This document provides an overview of the biomechanics of various knee ligaments and structures. It describes the anatomy and function of the medial collateral ligament, lateral collateral ligament, anterior cruciate ligament, posterior cruciate ligament, posterior capsule ligaments, and iliotibial band. Each structure's role in resisting different motions at the knee joint is discussed, as well as how their function may change with knee position. Muscular effects on ligament strain are also reviewed.
The document discusses open and closed kinetic chain exercises. It defines an open kinetic chain as having a free distal segment, like in a knee extension where the lower leg can move freely. Open chain exercises isolate single joints with rotary motion in one plane. Closed kinetic chain exercises have both segments stationary, like in a squat where the feet don't move. Closed chain exercises work multiple joints simultaneously and produce linear motion patterns at joints from axial loading. Examples of both open and closed chain upper and lower body exercises are provided.
The foot is a complex biomechanical structure that must provide both stability and mobility. It is composed of 26 bones arranged in 3 sections - the rearfoot, midfoot, and forefoot. The main joints of the foot include the subtalar, transverse tarsal, tarsometatarsal, metatarsophalangeal, and interphalangeal joints. These joints allow for pronation, supination, and a metatarsal break during gait to absorb shock and efficiently propel the body forward. The foot's unique bone structure and motion are finely tuned to support weight-bearing activities while accommodating varied surfaces.
BIOMECHANICS OF HIP JOINT BY Dr. VIKRAMVicky Vikram
The hip joint is a ball-and-socket joint that allows flexion, extension, abduction, adduction, and rotation. It is formed by the acetabulum of the pelvis articulating with the femoral head. The primary function is to support the weight of the upper body. Key biomechanical aspects include the angles of inclination and torsion of the femur, congruence of the joint surfaces, and forces transmitted during weight bearing that are balanced by the joint capsule and trabecular bone structure. Motion occurs through tilting and rotation of the pelvis on a fixed femur. Surrounding muscles provide dynamic stability and control movement.
3. biomechanics of Patellofemoral jointSaurab Sharma
The patellofemoral joint is one of the most incongruent joints in the body. It depends on static structures like the lateral lip of the femoral condyle and the length of the patellar tendon for stability. Forces through the joint increase significantly during activities like squatting or ascending stairs. Pathologies of the patellofemoral joint can include osteoarthritis, ligament injuries, meniscal tears, and patellofemoral pain syndrome resulting from an imbalance of forces through the joint.
As a general term, traction means pulling on part of the body.
Most often, traction uses mechanical force (sometimes generated by weights and pulleys) to put tension on a displaced bone or joint, such as a dislocated shoulder, to put it back in position and keep it still. In the medical field, traction refers to the practice of slowly and gently pulling on a fractured or dislocated body part. It’s often done using ropes, pulleys, and weights. These tools help apply force to the tissues surrounding the damaged area.
The document summarizes the anatomy and biomechanics of the shoulder joint. It describes the three joints that make up the shoulder complex - the sternoclavicular joint, acromioclavicular joint, and glenohumeral joint. For each joint, it outlines the bony structures, ligaments, range of motion, and stabilizing muscles involved. It then discusses the kinetics of the glenohumeral joint, including the static stabilization of the humeral head both with the arm unloaded and loaded at the side through the resultant force of surrounding structures.
The document discusses open and closed kinetic chain exercises. It defines an open kinetic chain as having a free distal segment, like in a knee extension where the lower leg can move freely. Open chain exercises isolate single joints with rotary motion in one plane. Closed kinetic chain exercises have both segments stationary, like in a squat where the feet don't move. Closed chain exercises work multiple joints simultaneously and produce linear motion patterns at joints from axial loading. Examples of both open and closed chain upper and lower body exercises are provided.
The foot is a complex biomechanical structure that must provide both stability and mobility. It is composed of 26 bones arranged in 3 sections - the rearfoot, midfoot, and forefoot. The main joints of the foot include the subtalar, transverse tarsal, tarsometatarsal, metatarsophalangeal, and interphalangeal joints. These joints allow for pronation, supination, and a metatarsal break during gait to absorb shock and efficiently propel the body forward. The foot's unique bone structure and motion are finely tuned to support weight-bearing activities while accommodating varied surfaces.
BIOMECHANICS OF HIP JOINT BY Dr. VIKRAMVicky Vikram
The hip joint is a ball-and-socket joint that allows flexion, extension, abduction, adduction, and rotation. It is formed by the acetabulum of the pelvis articulating with the femoral head. The primary function is to support the weight of the upper body. Key biomechanical aspects include the angles of inclination and torsion of the femur, congruence of the joint surfaces, and forces transmitted during weight bearing that are balanced by the joint capsule and trabecular bone structure. Motion occurs through tilting and rotation of the pelvis on a fixed femur. Surrounding muscles provide dynamic stability and control movement.
3. biomechanics of Patellofemoral jointSaurab Sharma
The patellofemoral joint is one of the most incongruent joints in the body. It depends on static structures like the lateral lip of the femoral condyle and the length of the patellar tendon for stability. Forces through the joint increase significantly during activities like squatting or ascending stairs. Pathologies of the patellofemoral joint can include osteoarthritis, ligament injuries, meniscal tears, and patellofemoral pain syndrome resulting from an imbalance of forces through the joint.
As a general term, traction means pulling on part of the body.
Most often, traction uses mechanical force (sometimes generated by weights and pulleys) to put tension on a displaced bone or joint, such as a dislocated shoulder, to put it back in position and keep it still. In the medical field, traction refers to the practice of slowly and gently pulling on a fractured or dislocated body part. It’s often done using ropes, pulleys, and weights. These tools help apply force to the tissues surrounding the damaged area.
The document summarizes the anatomy and biomechanics of the shoulder joint. It describes the three joints that make up the shoulder complex - the sternoclavicular joint, acromioclavicular joint, and glenohumeral joint. For each joint, it outlines the bony structures, ligaments, range of motion, and stabilizing muscles involved. It then discusses the kinetics of the glenohumeral joint, including the static stabilization of the humeral head both with the arm unloaded and loaded at the side through the resultant force of surrounding structures.
The document discusses biomechanics of the knee complex, focusing on tibiofemoral joint function and kinematics. It describes the primary motions of the knee as flexion/extension along with lesser rotations and translations. Flexion/extension occurs through rolling and gliding motions of the femur on the tibia. The cruciate ligaments and menisci help guide these motions while allowing for joint incongruence. Range of motion depends on other factors like flexion angle and involvement of other joints.
This document provides an overview of the anatomy of the knee joint. It describes the bones that make up the knee (femur, tibia, patella). It then discusses the tibiofemoral joint and patellofemoral joint. It provides details on the degrees of freedom in the knee joint and the ligaments, menisci, and other structures that are involved in the knee joint.
The document discusses static and dynamic stability of the glenohumeral joint. Statically, the joint is stabilized by the humeral head resting in the glenoid fossa, creating negative pressure. The rotator cuff muscles and deltoid provide a vertical force to counteract gravity. Dynamically, the deltoid, rotator cuff, biceps and scapulohumeral rhythm work together to precisely guide humeral movement and stabilize the joint throughout its range of motion. Scapulohumeral rhythm involves greater scapular movement in the first 90 degrees of arm elevation compared to humeral movement.
The document discusses the scapulohumeral rhythm, which is the coordinated movement between the glenohumeral joint and scapulothoracic joint during shoulder movement. Specifically, it notes that for every 2 degrees of shoulder abduction or flexion, the scapula upwardly rotates approximately 1 degree. This ratio maintains proper shoulder range of motion and prevents impingement. Clinical issues like frozen shoulder and scapular winging can result from impairments affecting the scapulothoracic joint.
This document discusses trick movements, or unnatural movements that occur when a muscle is paralyzed or inhibited. It defines trick movements and describes several types: direct/indirect substitution where another muscle takes over the action of the paralyzed prime mover; accessory insertion where a muscle's insertion allows it to assist a weak muscle's movement; tendon action where shortening of a tendon produces movement; rebound where relaxation of an antagonist muscle causes apparent agonist contraction; and gravity assistance where body positioning uses gravity to assist weak muscles. Examples are provided for each type of trick movement.
This document discusses the structure and biomechanics of the hip joint. It describes the anatomy of the acetabulum and femoral head that form the ball and socket joint. It details the angles of the acetabulum, including the center edge angle and acetabular anteversion angle. It also describes the acetabular labrum and angles of the femur relative to the shaft. The primary function of the hip joint is to support weight and enable mobility through walking, running, and other activities.
The knee is a complex joint composed of the tibiofemoral and patellofemoral joints. It functions to provide mobility and support body weight during both static and dynamic activities. The knee joint contains menisci that increase joint congruence and distribute weight forces. It also contains cruciate and collateral ligaments that restrict motion and provide stability. During flexion and extension, the tibia glides and rotates on the femur through rolling and sliding motions controlled by the ligaments and menisci.
The document discusses the biomechanics of the hip joint, including its structure, motions, stability mechanisms, and common injuries. The hip is a ball-and-socket joint between the pelvis and femur that allows for flexion/extension, abduction/adduction, and internal/external rotation. Stability is provided by bony configuration, cartilage, ligaments like the iliofemoral and ischiofemoral, and large muscles like the gluteals. Common injuries include fractures from direct impacts or degenerative joint disease from repeated stresses.
This document summarizes the origins, insertions, actions and roles of various muscles around the hip and knee. It describes the rectus femoris, vastus intermedius, vastus lateralis, vastus medialis and other quadriceps muscles as knee extensors and hip flexors. It also outlines the hamstrings muscles and their actions as knee flexors and hip extensors. Additionally, it provides details on stabilizer muscles like the tensor fasciae latae, sartorius, gracilis, popliteus and others. The roles of these muscles in dynamic stabilization of the joints are emphasized.
The document defines the Q-angle as the angle formed between a line from the ASIS to the midpoint of the patella and a line from the midpoint of the patella to the tibial tubercle. It represents the angle of pull of the quadriceps muscles. The normal range is 10-14 degrees for men and 15-23 degrees for women. Factors that can increase the Q-angle include muscle imbalances, tight iliotibial bands, genu valgum, medial femoral torsion, and lateral tibial rotation.
This document discusses strategies to reduce force on the hip joint for individuals with hip osteoarthritis or weak hip abductor muscles. It analyzes using a lateral lean, cane on the same side, or cane on the opposite side. A lateral lean reduces gravitational torque but increases energy expenditure. A cane on the same side provides some relief but a cane on the opposite side may offset gravity's torque, reducing the need for abductor muscle force and joint compression to just body weight. However, the full distance between hand and hip may overestimate the cane's effectiveness.
Muscle energy techniques (MET) involve voluntary muscle contractions by the patient against a counterforce applied by the practitioner. The goal is to move restrictive barriers and normalize muscle and fascial restrictions. Key elements include controlled joint positioning, patient-applied muscle contractions in a specific direction, and operator counterforce. MET can be used to lengthen shortened muscles, strengthen weakened muscles, reduce pain and edema, and increase joint mobility. It relies on principles like post-isometric relaxation and reciprocal inhibition. Careful technique and patient/practitioner coordination are important for success. MET can help many somatic dysfunctions but requires an understanding of indications and contraindications.
This document provides an overview of biomechanics of the elbow, including its structure, function, kinematics, muscle actions, and stability mechanisms. It describes the three joints that make up the elbow complex - the humeroulnar joint, humeroradial joint, and proximal radioulnar joint. It details the motions of elbow flexion/extension and forearm pronation/supination, identifying the muscles, ligaments, and bony structures involved in each motion. Common injuries to the elbow from direct stresses and repeated stresses are also summarized.
Posture - a perquisite for functional abilities in daily life. Posture is a combination of anatomy and physiology with inherent application of bio-mechanics and kinematics. Sitting, standing, walking are all functional activities depending on the ability of the body to support that posture to carry out each activity. Injuries and pathologies either postural or structural can massively change the bio-mechanics of posture and thus affect functional abilities.
This document discusses biomechanics and activities of daily living. It defines biomechanics as the study of mechanics in the human body. Functional biomechanics looks at the link between the human body and its environment. Biomechanics consists of kinematics, the description of motion, and kinetics, the forces producing motion. Common activities like running, lifting, and walking are analyzed in terms of joint motion and ground reaction forces. Proper form and muscle engagement can reduce stresses, as seen in squat lifting versus stoop lifting.
This document provides an overview of the anatomy of the ankle and foot complex. It describes the bones and joints that make up the ankle, including the ankle joint (talocrural joint), subtalar joint, and other tarsal joints. It defines the motions of the ankle like dorsiflexion, plantarflexion, inversion, and eversion. It details the ligaments supporting each joint and their functions. It explains the axes of motion for the ankle and subtalar joints and how their motions change between weight-bearing and non-weight-bearing states.
This document discusses the biomechanics of the knee joint, including its structure, stability mechanisms, and kinetics. It describes the knee as a complex hinge joint made up of the femur, tibia, and patella. Key stabilizing structures include the collateral and cruciate ligaments, menisci, and surrounding muscles. The document outlines the knee's degrees of freedom and range of motion, including screw-home rotation. It also analyzes the forces acting on the knee during activities like walking, cycling, and squatting using free body diagrams and dynamic analysis.
This document discusses prehension, or gripping, which is made possible by the opposable thumb in humans. It describes two main types of grip: power grip, which involves the whole hand and is used to hold cylindrical or spherical objects, and precision grip, which requires finer motor control and pad-to-pad, tip-to-tip, or pad-to-side contact between the thumb and fingers. Specific grips like hook, spherical, and lateral grips are subtypes of power grip. Precision grips depend on intact sensation and muscles like the flexor pollicis brevis and opponens pollicis. The functional position of the wrist and fingers optimizes power and efficiency of grip.
The menisci of the knee play several important roles. They improve tibiofemoral congruence, distribute weight-bearing forces to reduce friction and act as shock absorbers. The medial meniscus is C-shaped while the lateral is four-fifths circular. Both are attached via ligaments to limit motion, with the medial having greater restraint. This reduces its mobility and increases injury risk. The menisci assume 50-70% of compressive loads. Their attachments help increase contact area between the femur and tibia, reducing joint stress on cartilage. Loss of a meniscus nearly doubles femoral and increases tibial plateau stresses, risking degeneration.
The document discusses the structure and function of the knee joint capsule. It describes how the capsule consists of an outer fibrous layer and inner synovial membrane. The synovial membrane folds within the joint and its intricate folds create separations within the capsule. The capsule provides stability and limits motion of the knee joint. It is reinforced medially, laterally and posteriorly by ligaments. The synovial membrane secretes and absorbs synovial fluid for joint lubrication.
The document discusses biomechanics of the knee complex, focusing on tibiofemoral joint function and kinematics. It describes the primary motions of the knee as flexion/extension along with lesser rotations and translations. Flexion/extension occurs through rolling and gliding motions of the femur on the tibia. The cruciate ligaments and menisci help guide these motions while allowing for joint incongruence. Range of motion depends on other factors like flexion angle and involvement of other joints.
This document provides an overview of the anatomy of the knee joint. It describes the bones that make up the knee (femur, tibia, patella). It then discusses the tibiofemoral joint and patellofemoral joint. It provides details on the degrees of freedom in the knee joint and the ligaments, menisci, and other structures that are involved in the knee joint.
The document discusses static and dynamic stability of the glenohumeral joint. Statically, the joint is stabilized by the humeral head resting in the glenoid fossa, creating negative pressure. The rotator cuff muscles and deltoid provide a vertical force to counteract gravity. Dynamically, the deltoid, rotator cuff, biceps and scapulohumeral rhythm work together to precisely guide humeral movement and stabilize the joint throughout its range of motion. Scapulohumeral rhythm involves greater scapular movement in the first 90 degrees of arm elevation compared to humeral movement.
The document discusses the scapulohumeral rhythm, which is the coordinated movement between the glenohumeral joint and scapulothoracic joint during shoulder movement. Specifically, it notes that for every 2 degrees of shoulder abduction or flexion, the scapula upwardly rotates approximately 1 degree. This ratio maintains proper shoulder range of motion and prevents impingement. Clinical issues like frozen shoulder and scapular winging can result from impairments affecting the scapulothoracic joint.
This document discusses trick movements, or unnatural movements that occur when a muscle is paralyzed or inhibited. It defines trick movements and describes several types: direct/indirect substitution where another muscle takes over the action of the paralyzed prime mover; accessory insertion where a muscle's insertion allows it to assist a weak muscle's movement; tendon action where shortening of a tendon produces movement; rebound where relaxation of an antagonist muscle causes apparent agonist contraction; and gravity assistance where body positioning uses gravity to assist weak muscles. Examples are provided for each type of trick movement.
This document discusses the structure and biomechanics of the hip joint. It describes the anatomy of the acetabulum and femoral head that form the ball and socket joint. It details the angles of the acetabulum, including the center edge angle and acetabular anteversion angle. It also describes the acetabular labrum and angles of the femur relative to the shaft. The primary function of the hip joint is to support weight and enable mobility through walking, running, and other activities.
The knee is a complex joint composed of the tibiofemoral and patellofemoral joints. It functions to provide mobility and support body weight during both static and dynamic activities. The knee joint contains menisci that increase joint congruence and distribute weight forces. It also contains cruciate and collateral ligaments that restrict motion and provide stability. During flexion and extension, the tibia glides and rotates on the femur through rolling and sliding motions controlled by the ligaments and menisci.
The document discusses the biomechanics of the hip joint, including its structure, motions, stability mechanisms, and common injuries. The hip is a ball-and-socket joint between the pelvis and femur that allows for flexion/extension, abduction/adduction, and internal/external rotation. Stability is provided by bony configuration, cartilage, ligaments like the iliofemoral and ischiofemoral, and large muscles like the gluteals. Common injuries include fractures from direct impacts or degenerative joint disease from repeated stresses.
This document summarizes the origins, insertions, actions and roles of various muscles around the hip and knee. It describes the rectus femoris, vastus intermedius, vastus lateralis, vastus medialis and other quadriceps muscles as knee extensors and hip flexors. It also outlines the hamstrings muscles and their actions as knee flexors and hip extensors. Additionally, it provides details on stabilizer muscles like the tensor fasciae latae, sartorius, gracilis, popliteus and others. The roles of these muscles in dynamic stabilization of the joints are emphasized.
The document defines the Q-angle as the angle formed between a line from the ASIS to the midpoint of the patella and a line from the midpoint of the patella to the tibial tubercle. It represents the angle of pull of the quadriceps muscles. The normal range is 10-14 degrees for men and 15-23 degrees for women. Factors that can increase the Q-angle include muscle imbalances, tight iliotibial bands, genu valgum, medial femoral torsion, and lateral tibial rotation.
This document discusses strategies to reduce force on the hip joint for individuals with hip osteoarthritis or weak hip abductor muscles. It analyzes using a lateral lean, cane on the same side, or cane on the opposite side. A lateral lean reduces gravitational torque but increases energy expenditure. A cane on the same side provides some relief but a cane on the opposite side may offset gravity's torque, reducing the need for abductor muscle force and joint compression to just body weight. However, the full distance between hand and hip may overestimate the cane's effectiveness.
Muscle energy techniques (MET) involve voluntary muscle contractions by the patient against a counterforce applied by the practitioner. The goal is to move restrictive barriers and normalize muscle and fascial restrictions. Key elements include controlled joint positioning, patient-applied muscle contractions in a specific direction, and operator counterforce. MET can be used to lengthen shortened muscles, strengthen weakened muscles, reduce pain and edema, and increase joint mobility. It relies on principles like post-isometric relaxation and reciprocal inhibition. Careful technique and patient/practitioner coordination are important for success. MET can help many somatic dysfunctions but requires an understanding of indications and contraindications.
This document provides an overview of biomechanics of the elbow, including its structure, function, kinematics, muscle actions, and stability mechanisms. It describes the three joints that make up the elbow complex - the humeroulnar joint, humeroradial joint, and proximal radioulnar joint. It details the motions of elbow flexion/extension and forearm pronation/supination, identifying the muscles, ligaments, and bony structures involved in each motion. Common injuries to the elbow from direct stresses and repeated stresses are also summarized.
Posture - a perquisite for functional abilities in daily life. Posture is a combination of anatomy and physiology with inherent application of bio-mechanics and kinematics. Sitting, standing, walking are all functional activities depending on the ability of the body to support that posture to carry out each activity. Injuries and pathologies either postural or structural can massively change the bio-mechanics of posture and thus affect functional abilities.
This document discusses biomechanics and activities of daily living. It defines biomechanics as the study of mechanics in the human body. Functional biomechanics looks at the link between the human body and its environment. Biomechanics consists of kinematics, the description of motion, and kinetics, the forces producing motion. Common activities like running, lifting, and walking are analyzed in terms of joint motion and ground reaction forces. Proper form and muscle engagement can reduce stresses, as seen in squat lifting versus stoop lifting.
This document provides an overview of the anatomy of the ankle and foot complex. It describes the bones and joints that make up the ankle, including the ankle joint (talocrural joint), subtalar joint, and other tarsal joints. It defines the motions of the ankle like dorsiflexion, plantarflexion, inversion, and eversion. It details the ligaments supporting each joint and their functions. It explains the axes of motion for the ankle and subtalar joints and how their motions change between weight-bearing and non-weight-bearing states.
This document discusses the biomechanics of the knee joint, including its structure, stability mechanisms, and kinetics. It describes the knee as a complex hinge joint made up of the femur, tibia, and patella. Key stabilizing structures include the collateral and cruciate ligaments, menisci, and surrounding muscles. The document outlines the knee's degrees of freedom and range of motion, including screw-home rotation. It also analyzes the forces acting on the knee during activities like walking, cycling, and squatting using free body diagrams and dynamic analysis.
This document discusses prehension, or gripping, which is made possible by the opposable thumb in humans. It describes two main types of grip: power grip, which involves the whole hand and is used to hold cylindrical or spherical objects, and precision grip, which requires finer motor control and pad-to-pad, tip-to-tip, or pad-to-side contact between the thumb and fingers. Specific grips like hook, spherical, and lateral grips are subtypes of power grip. Precision grips depend on intact sensation and muscles like the flexor pollicis brevis and opponens pollicis. The functional position of the wrist and fingers optimizes power and efficiency of grip.
The menisci of the knee play several important roles. They improve tibiofemoral congruence, distribute weight-bearing forces to reduce friction and act as shock absorbers. The medial meniscus is C-shaped while the lateral is four-fifths circular. Both are attached via ligaments to limit motion, with the medial having greater restraint. This reduces its mobility and increases injury risk. The menisci assume 50-70% of compressive loads. Their attachments help increase contact area between the femur and tibia, reducing joint stress on cartilage. Loss of a meniscus nearly doubles femoral and increases tibial plateau stresses, risking degeneration.
The document discusses the structure and function of the knee joint capsule. It describes how the capsule consists of an outer fibrous layer and inner synovial membrane. The synovial membrane folds within the joint and its intricate folds create separations within the capsule. The capsule provides stability and limits motion of the knee joint. It is reinforced medially, laterally and posteriorly by ligaments. The synovial membrane secretes and absorbs synovial fluid for joint lubrication.
This document provides an overview of the biomechanics of the knee complex. It describes the anatomy of the tibiofemoral and patellofemoral joints, including the femoral condyles, tibial plateaus, and alignment of the femur and tibia. It also discusses how weight-bearing forces are distributed between the medial and lateral compartments during activities like standing, walking, and with conditions like genu valgum or genu varum. The complex biomechanics of the knee allow for both mobility and stability through interactions of its bones, cartilage, ligaments and muscles.
This document discusses forces on the hip joint during bilateral and unilateral stance. In bilateral stance, each hip experiences approximately one-third of body weight compression from gravity. Additional compression may come from hip muscles. In unilateral stance, the supporting hip experiences compression of approximately five-sixths of body weight from gravity. Additional compression comes from hip abductor muscle contraction needed to counter the adduction torque from the weight of the body. Together these forces can result in a total hip joint compression of around 2-3 times body weight in unilateral stance.
This document discusses the function and biomechanics of the hip joint. It describes the three motions of the hip joint - flexion/extension, abduction/adduction, and medial/lateral rotation - as movements of the femoral head within the acetabulum. It also discusses pelvic motions including anterior/posterior tilt, lateral tilt, and anterior/posterior rotation which produce the same motions at the hip joint. Compensatory lumbar spine motions that accompany various pelvic motions in weight-bearing are also described.
This document discusses the bursae of the knee complex. It notes that numerous bursae help prevent friction between ligaments, muscles, and bones during movement of the knee. Specifically, it describes the locations and functions of the suprapatellar, subpopliteal, and gastrocnemius bursae which connect to the synovial joint capsule. The positions of flexion, extension, and semiflexion of the knee affect the pressure on these bursae and distribution of synovial fluid within the joint. Additional bursae around the knee, such as the prepatellar and infrapatellar bursae, reduce friction and allow skin movement over the patella.
The document discusses various pathologies that can affect the hip joint due to alterations in biomechanics. Small changes in forces or joint structure can lead to increased stress and injury over time. Common issues include arthritis/arthrosis from wear and tear, and fractures of the femoral neck which become more likely with age-related bone loss. Conditions like coxa valga/vara and torsion abnormalities of the femur can further impact forces on the joint and predispose to problems. Understanding hip biomechanics and how dysfunctions can influence other areas is important for evaluation and treatment.
This document discusses the muscles that act on the knee joint. It describes the knee flexor and extensor muscle groups in detail, including their attachments, actions, and functional roles. Specifically, it outlines the seven muscles that flex the knee and notes their ability to produce various frontal and transverse plane motions. It then discusses the four muscles that make up the primary knee extensor group, the quadriceps femoris muscle, and how the patella influences their function.
Sacral fractures can result from a blow to the tailbone area from a fall. Women are more commonly affected than men. Physical examination may reveal bruising and tenderness over the sacrum or coccyx. X-rays sometimes do not show fractures if they are minor. More serious fractures are classified by Denis zones, with zone III fractures through the sacral body posing the highest risk of neurological injuries like loss of bladder control. Treatment depends on fracture stability and neurological involvement, ranging from rest and cushioning to sacral laminectomy or open reduction and internal fixation. Coccyx fractures from falls also cause severe pain but generally require only analgesics and cushioning.
The document discusses the muscles that act on the knee joint. It describes the seven muscles that flex the knee - the semimembranosus, semitendinosus, biceps femoris, sartorius, gracilis, popliteus, and gastrocnemius. It also discusses the four knee extensor muscles which make up the quadriceps group. Additionally, it explores how some muscles like the hamstrings and gastrocnemius act as both flexors and extensors depending on the position of other joints they cross.
The document provides details on a case history presentation for a 14-year-old soccer player named Nasser Naimi who injured his right ankle. It describes the anatomy of the ankle bones including the tibia, fibula, and talus. It outlines Nasser's injury occurring from being kicked on the outside of his ankle during a game. On examination, he had swelling, bruising, pain on all ankle movements and stability tests. Imaging showed a grade 3 tear of the ATFL ligament and high grade CFL tear. The diagnosis was lateral ligament tears and he was prescribed physical therapy including RICE treatment, bracing, and exercises to restore flexibility, strength, and function over 12 weeks.
This document discusses the biomechanics of the knee complex, focusing on tibiofemoral joint function and kinematics. It describes the primary motions of the knee as flexion/extension along with smaller amounts of medial/lateral rotation and varus/valgus motion. It explains how the cruciate ligaments and menisci facilitate and guide knee motion through rolling and gliding movements. The normal range of motion for flexion/extension is also outlined.
This document discusses the biomechanics of the patellofemoral joint. It describes the anatomy of the patella and its articulation with the femur. As the knee flexes and extends, the patella translates and rotates in complex motions to maintain contact within the femoral groove. The patellofemoral joint experiences high stresses from quadriceps forces, especially between 30-90 degrees of flexion when contact area is increasing. Several mechanisms help minimize stresses on the joint.
Rib fractures are commonly caused by blunt chest trauma and are often seen following motor vehicle crashes and falls. While usually not life-threatening on their own, they can indicate more severe underlying injuries to the chest or abdomen. Treatment focuses on pain management to prevent respiratory complications and complications are more common in elderly patients and those with multiple rib fractures.
The document discusses hip joint anatomy and biomechanics from the perspective of total hip arthroplasty. It describes key terms like kinematics and kinetics. It provides details on normal ranges of motion for the hip. It discusses femoral head anatomy and the forces acting on the hip during single leg stance, which can be up to 4 times body weight. Factors like leg length, weight, and abductor lever arm influence joint loading.
The document summarizes the roles and functions of various ligaments in the knee complex. It discusses the medial collateral ligament (MCL), lateral collateral ligament (LCL), anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and other ligaments. It describes how each ligament resists different motions like varus, valgus, rotation and translation. It also explains how the ligaments work together and how their functions change with the position of the knee. The roles of muscles in loading and stabilizing the ligaments is also summarized.
The document discusses internal derangements of the knee, focusing on injuries to ligaments and cartilages. It describes the anatomy of the knee joint and then examines several specific ligament injuries in more detail, including the medial collateral ligament, lateral collateral ligament, and anterior cruciate ligament. For each, it covers anatomy, mechanisms of injury, clinical findings, and treatment approaches. The most common derangements involve injuries to the medial collateral ligament, medial meniscus, and anterior cruciate ligament.
Anatomy and Biomechanics of the Elbow Jointorthoprince
The elbow is stabilized both statically by bony articulations and ligaments, and dynamically by muscles. The three primary static stabilizers are the ulnohumeral articulation, anterior bundle of the MCL, and lateral collateral ligament complex. Muscles that cross the elbow act as dynamic stabilizers. The coronoid process, radial head, and ligaments all play important roles in stability, with the MCL and LCL being the primary soft tissue constraints. Proper biomechanics and force distribution across the elbow joint are necessary for normal function.
This document discusses knee injuries and disorders (IDKs) of the ligaments and cartilages. It begins by describing the anatomy of the knee joint, which is the largest joint in the body. It is a synovial hinge joint composed of the femur, tibia, patella, and fibula. The knee joint contains ligaments like the anterior and posterior cruciate ligaments, and medial and lateral collateral ligaments that stabilize the knee. It also contains menisci that act as shock absorbers. Common knee disorders involve sprains or tears of these ligaments and tears of the menisci. Physical trauma is usually the cause of IDKs, often from sports injuries or accidents. The document then
The document summarizes the biomechanics of the elbow joint. It discusses the static and dynamic stabilizers of the elbow, including the primary static constraints of the ulnohumeral articulation, anterior bundle of the MCL, and lateral collateral ligament complex. It also describes the osteology and articular surfaces of the elbow joint and how flexion and extension enhance osseous stability. Key soft tissues like the medial and lateral collateral ligament complexes are explained. The roles of the coronoid process, radial head, and muscles in dynamic stabilization are highlighted. Joint forces at the elbow are distributed between the ulnohumeral and radiocapitellar joints.
This document provides an overview of the biomechanics of the knee complex. It describes the anatomy of the tibiofemoral and patellofemoral joints, including the femoral condyles, tibial plateaus, and alignment of the femur and tibia. It also discusses how weight bearing forces are distributed during static and dynamic activities, and how malalignment can increase stresses on the medial or lateral compartments.
The shoulder is one of the most unstable joints in the body due to its anatomy. Recurrent dislocations are influenced by age, return to contact sports, hyperlaxity, and glenoid or humeral defects. Younger patients and those returning to contact sports have higher recurrence rates. The glenohumeral ligaments, labrum, rotator cuff muscles, scapular positioning, and force couples work together to provide stability. Instability can be caused by traumatic injuries like Bankart lesions or atraumatic factors like muscle imbalances. Classification systems categorize instability as acute/chronic, directional, traumatic/atraumatic, and whether surgery or rehabilitation is typically required.
The shoulder is one of the most unstable joints in the body due to its anatomy. Recurrent dislocations are influenced by age, return to contact sports, hyperlaxity, and glenoid or humeral defects. Younger patients and those returning to contact sports have higher recurrence rates. The glenohumeral ligaments, labrum, rotator cuff muscles, scapular positioning, and force couples work together to provide stability. Instability can be caused by traumatic injuries like Bankart lesions or atraumatic factors like muscle imbalances. Classification systems categorize instability as acute/chronic, directional, traumatic/atraumatic, and whether surgery or rehabilitation is typically required.
This document provides an overview of the biomechanics of the knee complex. It describes the anatomy of the tibiofemoral and patellofemoral joints, including the femoral condyles, tibial plateaus, and surrounding ligaments. It explains that the knee allows for flexion, extension, and rotation. It also discusses how the alignment of the femur and tibia influences weight distribution and stresses on the medial and lateral compartments during activities like walking. Abnormal alignments like genu valgum or varum can increase risks of conditions like osteoarthritis.
The ankle/foot complex allows both stability and mobility through its structures. It bears weight and provides stability through the ankle joint and subtalar joint. The ankle joint permits dorsiflexion and plantarflexion around an oblique axis between the talus and tibia/fibula mortise. Ligaments including the deltoid and collateral ligaments support the joints. The talus wedging in the mortise enhances stability in dorsiflexion. Plantarflexion provides less stability.
This document discusses biomechanics concepts related to total hip arthroplasty (THA). It begins by defining key terms like force, vector, moment, work, and Newton's laws of motion. It then discusses biomechanical factors specific to the hip joint and THA, including joint reaction forces, component positioning and orientation, impingement, range of motion, and fixation methods. The focus is on how component design and surgical technique can affect stability, range of motion, wear and longevity of the hip replacement.
acl arthroscopic reconstruction single bundle vs double bundledrabhichaudhary88
The document discusses anterior cruciate ligament (ACL) repair, including a comparison of single bundle versus double bundle ACL reconstruction techniques. It provides details on ACL anatomy, biomechanics, injury mechanisms, treatment options, and surgical procedures. It also reviews findings from journal articles regarding clinical outcomes of single versus double bundle reconstruction.
1. The vertebral column is made up of 33 vertebrae divided into 5 regions with intervertebral discs between them.
2. It has both primary curves that are present from birth and secondary curves that develop with upright posture.
3. Each vertebra has a vertebral body in front and a vertebral arch in back, connected by pedicles with trabecular systems inside responding to stresses.
4. The intervertebral discs have a gelatinous nucleus pulposus surrounded by an outer fibrous anulus fibrosus and cartilage end plates separating it from the vertebrae.
Vertebral column... and Biomechanics.pptxsacootcbe
The vertebral column is a complex structure composed of 33 vertebrae and intervertebral disks that meets the demanding needs of mobility and stability. It protects the spinal cord and attaches the pelvis. Each vertebra has a cylindrical vertebral body anteriorly and an irregularly shaped neural arch posteriorly. The vertebrae are arranged into five regions with variations to meet functional demands. Curves in the vertebral column provide increased resistance to compression and change throughout development. Intervertebral disks separate and cushion vertebrae. The vertebral column undergoes motions of flexion, extension, lateral flexion, and coupled rotations which place structures under varying degrees of compression and tension resisted by ligaments, disks, and facets.
1. The elbow joint includes the humeroradial, humeroulnar, and superior radioulnar joints.
2. Flexion and extension at the elbow occurs around a fixed axis through the trochlea and capitulum.
3. Several ligaments and muscles work together to provide stability and control motion at the elbow and radioulnar joints during activities of daily living.
Total knee arthroplasty by dr..ammar m.sheetAmmar Sheet
This document provides information on total knee arthroplasty (TKA). It discusses knee anatomy and biomechanics. It describes the different designs of knee prostheses including unconstrained, constrained, and mobile bearing. It outlines surgical techniques for TKA including approaches, alignment, and balancing ligaments. It discusses indications and contraindications for TKA as well as techniques to ensure proper patellar tracking and joint line restoration. The goal of TKA is to relieve pain, correct alignment and restore function of the knee joint.
This is the Presentation on the topic "Pathomechanics of Knee Joint".
The presentation includes images and a clip for proper understanding. The sentences are framed in the way that you can learn it in a easy way.
This document discusses ankle instability and chronic ankle sprains. It begins by describing the anatomy of the ankle joint and its ligaments. It then explains that ankle sprains are common injuries, often caused by an inversion mechanism. Chronic ankle instability can develop after repeated sprains and is characterized by recurrent sprains, pain, and a feeling of the ankle giving way. Treatment of ankle sprains focuses on RICE initially, followed by bracing and physical therapy to improve strength, range of motion and proprioception. Surgery is rarely needed except for severe, unresolving cases.
12-year-old Male with Slipped Capital Femoral Epiphysis_ CurranCara Curran
This case report describes a 12-year-old male who presented to physical therapy 10 weeks post-op for an in-situ pinning procedure on his right hip due to a stable slipped capital femoral epiphysis. He had a history of hypothyroidism and obesity. Physical therapy focused on reducing pain and improving mobility, strength, and coordination through manual therapy, exercises, and neuromuscular retraining. Outcome measures showed a 72% increase on the Modified Harris Hip Score and decreased risk of injury on the Star Excursion Balance Test by the end of treatment. The report provides insight into examining and treating similar pediatric orthopedic patients.
Similar to Biomechanics of knee complex 4 ligaments (20)
Spondylolisthesis is the forward slippage of one vertebra over another and most commonly occurs between L4-L5 or L5-S1. It can be caused by developmental abnormalities, stress fractures of the pars interarticularis, degeneration of the disc and facets, trauma or tumors. Symptoms include lower back pain and sciatica. Conservative treatment involves rest and bracing while surgery is indicated for progressive, high grade or neurologically compressive slips. Surgical options include fusion with or without instrumentation to reduce the slip and decompress the nerves.
Hammer toe is a deformity of the toes characterized by an abnormal flexion of the proximal interphalangeal (PIP) joint. It is typically caused by tightness of the long flexor tendon or an underlying condition like bunions. Physical examination reveals calluses and accentuated toe flexion while standing. Treatment ranges from padding and stretching for mild cases to surgical correction involving tendon release or joint replacement for severe, fixed deformities.
The document discusses various measurements and lines used in chiropractic analysis of cervical and lumbar spine x-rays. In the cervical spine, measurements include the atlantodental interval and retrotracheal/retropharyngeal intervals. Key lines are the cervical gravity line and George's/spinolaminar lines. In the lumbar spine, measurements include the lumbar gravity line and Ulman's line is used to assess for spondylolisthesis. These measurements and lines help evaluate for conditions like trauma, degeneration, inflammation and abnormal spinal alignment.
This document discusses the classification, causes, symptoms, and treatment of kyphosis, which is an excessive curvature of the spine. It is classified into 15 major groups including postural disorders, Scheuermann's kyphosis, congenital disorders, paralytic disorders, and others. Treatment involves exercise, bracing, medication management, and surgery to correct the deformity and relieve pain or neurological symptoms. Surgical techniques range from posterior fusion to osteotomies to combined anterior-posterior procedures depending on the severity and rigidity of the deformity. The goals of surgery are to restore spinal alignment and remove any neural compression.
The document discusses Klippel-Feil syndrome, a congenital fusion of two or more cervical vertebrae. It causes a short neck and restricted neck movement. The cause is unknown but may involve failed segmentation of cervical vertebrae in fetal development. Patients can experience neck pain, torticollis, scoliosis, or neurological issues. Diagnosis involves physical exam and imaging like x-rays or MRI. Treatment depends on symptoms but may include surgery for deformity, instability, or neurological problems. Physiotherapy can help prevent degenerative changes while surgery can relieve pain or nerve compression.
Lymphoedema is a chronic condition caused by a buildup of lymphatic fluid in tissues, causing swelling. It can be primary, due to abnormalities in the lymphatic system, or secondary, caused by external factors like infection, inflammation, trauma, or cancer treatment. Management involves manual lymphatic drainage to promote fluid movement, compression therapy with bandages or garments, exercises, and skin care. Assessment measures swelling, skin changes, and limb function. Treatment aims to reduce swelling and prevent complications through a multi-modal approach as outlined by international lymphedema guidelines.
Lymphoedema is a chronic condition caused by a buildup of lymphatic fluid in tissues, causing swelling. It can be primary, due to abnormalities in the lymphatic system, or secondary, caused by external factors like infection, inflammation, trauma, or cancer treatment. Symptoms include swelling, heaviness, skin changes, and reduced mobility. Management involves manual lymphatic drainage to drain fluid, compression therapy with bandages or garments, exercises, and skin care. Additional treatments may include kinesiotaping or pneumatic compression pumps. The goal of treatment is to reduce swelling and prevent complications through proper lymphatic drainage and compression.
1. A Jefferson fracture is a burst fracture of the C1 vertebra (atlas) that results in a break of both the anterior and posterior arches of the ring.
2. It is caused by axial compression, often from a fall on the head, and may not be evident on lateral x-rays but displacement of the lateral masses on open-mouth views suggests a Jefferson fracture.
3. Treatment involves halo traction followed by a halo vest or posterior fusion to stabilize and fuse the fracture, with the goals of maintaining spinal alignment and preventing neurological injury.
1) Tibial shaft fractures occur in the diaphyseal region of the tibia and can result from high or low energy trauma.
2) Treatment goals are to restore proper alignment, stability, and allow bone healing within 10-12 weeks while rehabilitation lasts 12-24 weeks.
3) Treatment methods include casting, intramedullary nailing, or plating and depend on the fracture pattern and stability. Complications addressed include compartment syndrome, fat embolism, and nonunion.
Patellar fractures can be classified as displaced or nondisplaced. Treatment depends on the type of fracture and may include casting, open reduction and internal fixation, or partial/total patellectomy. The rehabilitation goals are to restore full range of motion, improve muscle strength and balance especially of the quadriceps, and normalize gait. Long-term considerations include the potential for loss of correction, degenerative changes, quadriceps shortening, knee flexion contractures, and chondromalacia patella.
This document discusses the physiotherapy management of femoral shaft fractures. It defines a femoral shaft fracture and notes they are usually caused by high-energy trauma. The treatment goals of orthopaedic and rehabilitation management are to restore alignment, stability, range of motion, muscle strength, and a normal gait pattern. Surgical treatment methods include intramedullary nail fixation, open reduction and internal plate fixation, external fixation, and skeletal traction. Rehabilitation focuses on regaining knee and hip range of motion and quadriceps and hamstring strength over 12-16 weeks.
This document discusses the physiotherapy management of femoral shaft fractures. It defines a femoral shaft fracture and explains that they are usually caused by high-energy trauma. The goals of treatment are to restore alignment, stability, range of motion, muscle strength, and normal gait. Surgical options include intramedullary nail fixation, open reduction and internal plate fixation, external fixation, and skeletal traction. Post-operative rehabilitation focuses on regaining knee and hip range of motion over 12-16 weeks. Complications may include nonunion, hardware pain, quadriceps adhesions, and hamstring shortening.
This document discusses supracondylar fractures of the femur. It defines these fractures as involving the distal aspect of the femur, including the distal 8 to 15 cm. Complex classification systems exist to define the degree of comminution and displacement. Treatment goals are to restore alignment with less than 1-2mm of articular step-off and achieve stability through restored bony congruity and rigid hardware fixation. Rehabilitation involves initial non-weight bearing, active range of motion exercises, and progressing to full weight bearing over 3 months.
1) Pelvic fractures are potentially life-threatening injuries that are increasing in incidence due to high-velocity trauma. Mortality rates are 10-15% and increase to 50% if the patient is hypotensive on initial presentation.
2) Surgical stabilization is usually indicated for rotationally or vertically unstable fractures (Tile B/C injuries). Non-operative treatment may be appropriate for stable fractures (Tile A) if displacement is minimal.
3) Anterior pelvic ring injuries involving >2.5cm of symphysis displacement are typically treated with open reduction and internal fixation. Posterior injuries are stabilized through approaches to the sacroiliac joint or ilium, using techniques like iliosacral
Osteotomy is a surgical procedure that cuts or divides bone to improve the function of a limb or provide stability to a joint. It involves three stages - dividing the bone, immobilizing it to allow correction and realignment, and physiotherapy to restore full function. Different types of osteotomies like closing wedge, opening wedge, and oblique cuts are used to correct various bone deformities and dysfunctions. Post-surgery physiotherapy focuses on reducing pain and swelling, maintaining stability, and gradually improving range of motion and strength. Complications can include under or overcorrection of deformity, nerve damage, compartment syndrome, and non-union of bone.
Biomechanics of knee complex 9 frontal plane patellofemoral jt stabilityDibyendunarayan Bid
The document discusses frontal plane patellofemoral joint stability. It describes the various soft tissue structures that provide stability to the patella, including the quadriceps muscles, retinaculum, and patellofemoral ligaments. Proper balance and tension between these structures is important for normal patellar tracking and preventing instability or increased stress.
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
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Rasamanikya is a excellent preparation in the field of Rasashastra, it is used in various Kushtha Roga, Shwasa, Vicharchika, Bhagandara, Vatarakta, and Phiranga Roga. In this article Preparation& Comparative analytical profile for both Formulationon i.e Rasamanikya prepared by Kushmanda swarasa & Churnodhaka Shodita Haratala. The study aims to provide insights into the comparative efficacy and analytical aspects of these formulations for enhanced therapeutic outcomes.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
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Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...
Biomechanics of knee complex 4 ligaments
1. Biomechanics
of the
Knee Complex : 4
DR. DIBYENDUNARAYAN BID [PT]
THE SARVAJANIK COLLEGE OF PHYSIOTHERAPY,
RAMPURA, SURAT
2. Ligaments
The roles of the various ligaments of the knee have
received extensive attention, which reflects their
importance for knee joint stability and the frequency
with which function is disrupted through injury.
3. Given the lack of bony restraint to virtually any of
the knee motions, the knee joint ligaments are
variously credited with resisting or controlling:
1. excessive knee extension
2. varus and valgus stresses at the knee (attempted
adduction or abduction of the tibia, respectively)
3. anterior or posterior displacement of the tibia beneath
the femur
4. medial or lateral rotation of the tibia beneath the
femur
5. combinations of anteroposterior displacements and
rotations of the tibia, together known as rotatory sta-
bilization of the tibia
4. The large body of literature available on ligamentous
function of the knee joint can be confusing and
appears contradictory.
This may be due to some confusion in terms as to
whether the tibia or the femur is being referenced,
but it is more likely due to complex and variable
functioning and to dissimilar testing conditions.
5. It is clear that ligamentous function can change,
depending on the position of the knee joint, on how
the stresses are applied, and on what active or
passive structures are concomitantly intact.
6. Medial Collateral Ligament
The MCL can be divided into a superficial portion
and a deep portion that are separated by a bursa.
The superficial portion of the MCL arises proximally
from the medial femoral epicondyle and travels
distally to insert into the medial aspect of the
proximal tibia distal to the pes anserinus (Fig. 11-15).
7.
8. The deep portion of the MCL is continuous with the
joint capsule, originates from the inferior aspect of
the medial femoral condyle, and inserts on the
proximal aspect of the medial tibial plateau.
Throughout its course of travel, the deep portion of
the MCL is rigidly affixed to the medial border of the
medial meniscus (see Fig. 11-10).
9. The MCL, specifically the superficial portion, is the
primary restraint to excessive abduction (valgus) and
lateral rotation stresses at the knee.
The knee joint is best able to resist a valgus stress at
full extension because the MCL is taut in this
position.
As joint flexion is increased, the MCL becomes more
lax and greater joint space opening is allowed
(medially gapping).47
10. With the knee flexed, the MCL plays a more critical
role in resisting valgus stress despite the permitted
joint gapping.
Grood et al. determined that at close to full
extension, the MCL accounted for 57% of the
restraining force against valgus opening, but at 25°
of knee flexion, the MCL accounted for 78% of the
load.
11. This difference is likely due to the greater bony
congruence and inclusion of other soft tissue
structures (e.g., posteromedial capsule, ACL) that at
full extension can more effectively assist with
checking a valgus stress.
The MCL also plays a supportive role in resisting
anterior translation of the tibia on the femur in the
absence of the primary restraints against anterior
tibial translation.
12. The MCL has the capacity to heal when ruptured or
damaged, because of its rich blood supply.
An isolated injury, therefore, does not often
necessitate surgical stabilization but is often left to
heal on its own, although this remodeling process
can take up to a year.
13. Lateral Collateral Ligament
The lateral collateral ligament (LCL) is located on
the lateral side of the tibiofemoral joint,
beginning proximally from the lateral femoral
condyle.
The LCL then travels distally to the fibular head
(Fig. 11-16), where it joins with the tendon of the
biceps femoris muscle to form the conjoined
tendon.
14.
15. Unlike the MCL, the LCL is not a thickening of the
capsule but is separate throughout much of its length
and is thereby considered to be an extracapsular
ligament.
The LCL is primarily responsible for checking varus
stresses, and like the MCL, limits varus motion most
successfully at full extension.
16. Grood et al. reported that at 5° of knee flexion, the
LCL accounted for 55% of the restraining force
against varus stress.
This capacity increased to 69% with the knee flexed
to 25°.
Although the LCL’s primary role is to resist varus
stresses, its orientation enables the LCL to limit
excessive lateral rotation of the tibia as well.
17. Anterior Cruciate Ligament
The relatively high rate of injury of the ACL by
athletes and other active individuals has resulted in
the ACL’s being one of the most highly researched
ligaments in the human body.
The ACL is attached to the anterior tibial spine (see
Fig. 11-9), where it extends superiorly and
posteriorly to attach to the posteromedial aspect of
the lateral femoral condyle (Fig. 11-17).
18.
19. The ACL courses posteriorly, laterally, and superiorly
from tibia to femur.
In addition, the ACL twists inwardly (medially) as it
travels proximally.
The ACL may also be considered to consist of two
separate bands that wrap around each other.
20. Each of these bands is thought to have a different
role in controlling tibiofemoral motion.
The anteromedial band (AMB) and the
posterolateral band (PLB) are each named for their
origins on the tibia.
The major blood supply to the ACL arises primarily
from the middle genicular artery.
21. The ACL functions as the primary restraint against
anterior translation (anterior shear) of the tibia on
the femur.
This role, however, belongs to either the AMB or the
PLB, depending on the knee flexion angle.
With the knee in full extension, the PLB is taut; as
knee flexion increases, the PLB loosens and the AMB
becomes tight, as demonstrated by the data plotted
in Figure 11-18.
22.
23. This shift in tension between the bands allows some
portion of the ACL to remain tight at all times.
In the intact joint, forces producing an anterior
translation of the tibia will result in maximal
excursion of the tibia at about 30° of flexion when
neither of the ACL bands are particularly tensed.
The ACL is also responsible for resisting
hyperextension of the knee.
24. There appears to be essentially no anterior
translation of the tibia possible in full extension
when many of the supporting passive structures of
the knee are taut (including the PLB of the ACL).
25. In addition to its primary restraint against anterior
shear, the ACL can act as a secondary restraint
against either varus or valgus motions (adduction
and abduction rotations respectively) at the knee.
With valgus loading, the lengths of both bands of the
ACL increase as knee flexion increases.
After injury to the MCL, a valgus moment will
increase the strain on the ACL throughout the flexion
range.
26. Although the ACL may not make an important
contribution to limiting medial rotation of the tibia,
medial rotation of the tibia on the femur increases
the strain on the AMB of the ACL, with the peak
strain occurring between 10° and 15°.
This is most likely due to the orientation of the ACL,
inasmuch as it winds its way medially around the
PCL, becoming tighter with medial rotation.
27. Regardless of the rotational effect on the ACL’s
loading pattern, injury to the ACL appears to occur
most commonly when the knee is slightly flexed and
the tibia is rotated in either direction in weight-
bearing.
In flexion and medial rotation, the ACL is tensed as it
winds around the PCL. In flexion and lateral
rotation, the ACL is tensed as it is stretched over the
lateral femoral condyle.
28. The muscles surrounding the knee joint are capable
of either inducing or minimizing strain in the ACL.
With the tibiofemoral joint in nearly full extension, a
quadriceps muscle contraction is capable of genera-
ting an anterior shear force on the tibia, thereby
increasing stress on the ACL.
29. Fleming et al. reported that the gastrocnemius
muscle similarly has the potential to translate the
tibia anteriorly and strain the ACL
because the proximal tendon of the gastrocnemius
wraps around the posterior tibia, effectively pushing
the tibia forward
when the muscle becomes tense through active
contraction or passive stretch.
30. The hamstring muscles are capable of inducing a
posterior shear force on the tibia throughout the
range of knee flexion, becoming more effective in
this role at greater knee flexion angles.
31. The hamstrings, therefore, have the potential to
relieve the ACL of some of the stress of checking
anterior shear of the tibia on the femur.
With the foot on the ground, the soleus muscle may
also have the ability to posteriorly translate the tibia
and assist the ACL in restraining anterior tibial
translation (Fig. 11-19).
32.
33. Given the potential of individual muscles to either
increase or decrease loads on the ACL, it is not
surprising that co-contraction of multiple muscles
across the knee can influence the strain on the ACL.
34. For example, co-contraction of the hamstrings and
quadriceps muscles will allow the hamstrings to
counter the anterior translatory effect of the
quadriceps and reduce the strain on the ACL.
35. In contrast, activation of both the gastrocnemius and
the quadriceps muscles results in greater strain on
the ACL than either muscle alone would produce,
unless the hamstrings also co-contract to mitigate
the anterior translation imposed by the
gastrocnemius.
36. Although muscular co-contraction will limit the
strain imposed on the ligaments of the knee, it comes
at a price.
Co-contraction will reduce the anterior shear force
on the tibia, but it increases joint compressive loads.
37. Posterior Cruciate Ligament
The PCL attaches distally to the posterior tibial spine
(see Fig. 11-9) and travels superiorly and somewhat
anteriorly to attach to the lateral aspect of the medial
femoral condyle (see Fig. 11-17).
Like the ACL, the PCL is intracapsular but
extrasynovial.
The PCL is a shorter and less oblique structure than
the ACL, with a cross-sectional area 120% to 150%
greater than that of the ACL.
38. The PCL blends with the posterior capsule and
periosteum as it crosses to its tibial attachment.
The PCL, again like the ACL, is typically divided into
an AMB and a PLB that are each named for their
tibial origins.
When the knee is close to full extension, the larger
and stronger AMB is lax, whereas the PLB becomes
taut. At 80° to 90° of flexion, the AMB is maximally
taut and the PLB is relaxed.
39. The PCL serves as the primary restraint to posterior
displacement, or posterior shear, of the tibia beneath
the femur.
In the fully extended knee, the PCL will absorb 93%
of a posteriorly directed load applied to the tibia.
This ability of the PCL to assume such a large load in
full extension restricts posterior displacement to very
minimal amounts.
40. Unlike the ACL, which resists force better at full
extension, the PCL is more adept at restraining
motion with the knee flexed.
Maximal posterior displacement of the tibia occurs at
75° to 90° of flexion, however, because with greater
knee flexion, the secondary restraints against
posterior translation become ineffective.
Sectioning of the PCL, therefore, increases posterior
translation at all angles of knee flexion.
41. Like the ACL, the PCL has a role in restraining varus and
valgus stresses at the knee and appears to play a role in
both restraining and producing rotation of the tibia.
The orientation of the PCL may result in a concomitant
lateral rotation of the tibia when posterior translational
forces are applied to the tibia.
The PCL resists tibial medial rotation at 90° but less so
in full extension.
The PCL does not resist lateral rotation very well.
42. In the absence of the PCL, muscles must be recruited to
actively stabilize against excessive posterior tibial
translation.
The popliteus muscle shares the role of the PCL in
resisting posteriorly directed forces on the tibia and can
contribute to knee stability when the PCL is absent.
In contrast, an isolated hamstring con-traction might
destabilize the knee joint in the absence of the PCL
because of its posterior shear on the tibia in the flexed
knee.
43. Contraction of the gastrocnemius muscle also
significantly strains the PCL at flexion angles greater
than 40° ,
whereas quadriceps contraction reduces the strain in
the PCL at knee flexion angles between 20° and 60°.
44. Ligaments of the Posterior Capsule
Several structures reinforce the “corners” of the posterior
knee joint capsule (Fig. 11-21).
The posteromedial corner of the capsule is reinforced by
the semimembranosus muscle, by its tendinous expansion
called the oblique popliteal ligament, and by the stronger
and more superficial POL.
The posterolateral corner of the capsule is reinforced by
the arcuate ligament, the LCL, and the popliteus muscle
and tendon.
The arcuate ligament is a Y-shaped capsular thickening
found in nearly 70% of knees.
(Attachments of these ligaments are given in Table 11-1.)
45.
46. Both the POL and the arcuate ligaments are taut in
full extension and assist in checking hyperextension
of the knee; the POL and arcuate ligaments also
check valgus and varus forces, respectively.
The orientation of the lateral branch of the arcuate
ligament allows it to become tight in tibial lateral
rotation.
47.
48.
49. Iliotibial Band
The IT band (or ITB) or IT tract is formed proximally
from the fascia investing the tensor fascia lata, the
glu-teus maximus, and the gluteus medius muscles.
The IT band continues distally to attach to the lateral
inter-muscular septum and inserts into the
anterolateral tibia (Gerdy’s tubercle),
reinforcing the anterolateral aspect of the knee joint
(see Fig. 11-16).
50. Despite the muscular attachments to the IT band, it
remains an essentially passive structure at the knee
joint; a contraction of the tensor fascia lata (TFL) or
the gluteus maximus muscles that attach to the IT
band proximally produce only minimal longitudinal
excursion of the band distally.
The IT band moves anterior to the knee joint axis as
the knee is extended, and posteriorly over the lateral
femoral condyle as the knee is flexed (Fig. 11-22).
51. The IT band, therefore, remains consistently taut,
regardless of the hip or knee’s position.
The fibrous connections of the IT band to the biceps
femoris and vastus lateralis muscles form a sling
behind the lateral femoral condyle,
assisting the ACL in checking posterior femoral (or
anterior tibial) translation when the knee joint is
nearly full extension.
52. With the knee in flexion, the combination of the IT
band, the LCL, and the popliteal tendon crossing
over each other increases the stability of the lateral
side of the joint and
even more effectively assists the ACL in resisting
anterior displacement of the tibia on the femur (see
Fig. 11-22).
53.
54. Despite its lateral location, the IT band alone
provides only minimal resistance to lateral joint
space opening.
The IT band also attaches to the patella via the
lateral patellofemoral ligament of the lateral
retinaculum.
As we shall see, this attachment of the IT band to the
lateral border of the patella may affect
patellofemoral function.