This document discusses the biomechanics of various knee ligaments including the medial collateral ligament (MCL), lateral collateral ligament (LCL), anterior cruciate ligament (ACL), and posterior cruciate ligament (PCL). It describes the anatomy and function of each ligament, noting that they resist different motions like valgus, varus, anterior/posterior tibial translation, and rotation. The roles and tensions of the ligaments change with knee position. Muscle forces can also impact ligament strains.
this slideshow describes about the hip joint anatomy, biomechanics and its pathomechanics along with angles of hip joint. the slide show also briefs about the pelvic femoral rhythm in daily activities
THis PPT will give you knowledge about the principles of shoulder; articulating surface, motions, ligamentous structure and musculature structure that related to shoulder region.
this is a slide show which gives in brief about anatomy and detailed description about biomechanics as well as pathomechanics of shoulder joint. various rhythms of shoulder complex are discussed as well along with the stability factors
1. Biomechanics of ankle joint subtalar joint and footSaurab Sharma
Biomechanics of Ankle joint- intended to share the powerpoint with first year undergraduate students at Kathmandu University School of Medical Sciences, Nepal.
Includes detailed description of BIOMECHANICS & PATHOMECHANICS OF KNEE JOINT AND PATELLOFEMORAL JOINT with recent evidences . Hope you find it useful!!
this slideshow describes about the hip joint anatomy, biomechanics and its pathomechanics along with angles of hip joint. the slide show also briefs about the pelvic femoral rhythm in daily activities
THis PPT will give you knowledge about the principles of shoulder; articulating surface, motions, ligamentous structure and musculature structure that related to shoulder region.
this is a slide show which gives in brief about anatomy and detailed description about biomechanics as well as pathomechanics of shoulder joint. various rhythms of shoulder complex are discussed as well along with the stability factors
1. Biomechanics of ankle joint subtalar joint and footSaurab Sharma
Biomechanics of Ankle joint- intended to share the powerpoint with first year undergraduate students at Kathmandu University School of Medical Sciences, Nepal.
Includes detailed description of BIOMECHANICS & PATHOMECHANICS OF KNEE JOINT AND PATELLOFEMORAL JOINT with recent evidences . Hope you find it useful!!
Extensor mechanism of finger, very easy notes. Referred from cynthia norkin. In this ppt in last two slides u can see the identify the parts. Its like a quiz for candidates who studying this ppt. They can able to know that how well they prepared this topic.
Thank you, From Liki pedia
(A student physiotherapist)
Biomwchanics of wrist and hand
- Kinematics and Kinetics of joints including flexion and extension mechanism
-Pathomechanics
- Prehension
-Functional position of wrist
Femoral Head (Superiorly, Medially, Anteriorly).
Acetabulum (Inferiorly, Laterally, Anteriorly).
Horseshoe-shaped (Acetabular Notch).
The deepest portion (Acetabular Fossa).
Labrum Acetabular:
Is a wedged fibrocartilaginous ring inserted into the acetabular rim to increase the acetabular concavity.
this PPT contain detailed kinetics & kinematics of ankle joint & all joints of foot complex, muscles of ankle & foot complex, plantar arches & weight distribution during standing.
Extensor mechanism of finger, very easy notes. Referred from cynthia norkin. In this ppt in last two slides u can see the identify the parts. Its like a quiz for candidates who studying this ppt. They can able to know that how well they prepared this topic.
Thank you, From Liki pedia
(A student physiotherapist)
Biomwchanics of wrist and hand
- Kinematics and Kinetics of joints including flexion and extension mechanism
-Pathomechanics
- Prehension
-Functional position of wrist
Femoral Head (Superiorly, Medially, Anteriorly).
Acetabulum (Inferiorly, Laterally, Anteriorly).
Horseshoe-shaped (Acetabular Notch).
The deepest portion (Acetabular Fossa).
Labrum Acetabular:
Is a wedged fibrocartilaginous ring inserted into the acetabular rim to increase the acetabular concavity.
this PPT contain detailed kinetics & kinematics of ankle joint & all joints of foot complex, muscles of ankle & foot complex, plantar arches & weight distribution during standing.
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.
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stockrebeccabio
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stock
Telegram: bmksupplier
signal: +85264872720
threema: TUD4A6YC
You can contact me on Telegram or Threema
Communicate promptly and reply
Free of customs clearance, Double Clearance 100% pass delivery to USA, Canada, Spain, Germany, Netherland, Poland, Italy, Sweden, UK, Czech Republic, Australia, Mexico, Russia, Ukraine, Kazakhstan.Door to door service
Hot Selling Organic intermediates
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Title: Sense of Smell
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 primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
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.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdf
Biomechanics of knee complex 4
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.