This study evaluated the test-retest reliability of a standing isometric hamstring bridge test to measure peak hamstring force. Six subjects performed the test on two separate occasions. The test involved measuring force produced during a 3-second maximal isometric contraction of the hamstrings while standing with hip and knee angles controlled. Results found no significant differences between tests and high intraclass correlation, suggesting the test produces reliable measures of peak force. However, the typical error and limits of agreement were quite large at around 15-16% of average force. The study concluded the test shows promise but technique consistency and potential fatigue effects need further investigation to improve reliability.
This study examined ankle muscle activity in faster and slower basketball players during a reactive cutting task. Eighteen male basketball players completed the Y-shaped agility test while electromyography measured activity of ankle muscles. Faster players were quicker in both preferred and non-preferred cuts. For the preferred cut, only the peroneus longus on the inside cut leg showed significantly greater activity in faster players. Otherwise, ankle muscle activity did not generally differentiate faster from slower players. While ankle function is important for cutting, strength training should target all ankle muscles to support cutting demands.
This study examined the effects of fatigue on landing forces between males and females performing single leg drop landings. Five participants (3 males and 2 females) performed drop landings before and after a fatiguing exercise. Forces were measured and normalized against body weight. Males showed a smaller decrease in peak vertical force but an increase in mediolateral force compared to females after fatigue. Females showed larger decreases in all forces, suggesting decreased dynamic stability and increased risk of ACL injury when fatigued. However, kinematic analysis is still needed to understand the gender differences in joint movement.
This presentation summarizes research on the relationships between forearm girth, grip strength, thigh girth, and vertical jump height. Six subjects were measured for height, weight, forearm girth, grip strength, thigh girth, and vertical jump. Strong positive correlations were found between forearm girth and grip strength. However, a negative correlation was found between thigh girth and vertical jump height, contrary to the initial hypothesis. The results provide insights for athletes and clinicians on how to assess muscular strength and power.
Eight male subjects performed cutting maneuvers with different footwear on artificial turf to measure lower extremity forces. Peak vertical ground reaction forces were compared between football cleats and turf shoes. The only statistically significant difference was that forces on the left leg when cutting right were greater for cleats than turf shoes. While few differences were statistically significant, the study found trends such as higher forces on the push-off leg when cutting and evidence of limb dominance when running straight. Further analysis of shear forces during cutting may provide more insight into footwear effects on performance and injury risk.
This document contains assessment findings and proposed training program for a 25-year old client with anterior pelvic tilt, leg length discrepancy, foot hyperpronation, and limited range of motion. Static and functional assessments identified impairments including excessive foot pronation, weak gluteal muscles, and anterior pelvic tilt. The proposed training focuses on self-myofascial release, static stretching, isolated strengthening, and integration exercises for the feet, hips, and core to address imbalances and improve posture. Regular participation in the program was limited by the client's work commitments.
This study investigated hip muscle activation during common closed-chain rehabilitation exercises and running in runners. Electromyography was used to measure gluteus maximus and medius activation during a resisted hip external rotation exercise, single leg squat with trunk rotation, forward lunge with resisted abduction, and running. The forward lunge elicited the highest hip muscle activation, but activation was still substantially less than during running. While the exercises activated the hip muscles more than non-weight bearing exercises, there remains a disconnect between activation during exercises and running. Further research is needed to identify exercises that more closely mimic muscle demands during running.
This document discusses a study on the relationship between body composition, foot angle, and functional efficiency in volleyball boosters and smashers. The study collected data on body composition, foot angle, and variables measuring functional efficiency (e.g. vertical jump, strength) from 25 boosters and smashers. It found a significant correlation between leg strength and body composition in boosters. It also found a significant correlation between standing broad jump and foot angle in boosters. However, it found mostly insignificant correlations for smashers and between other variables. The results suggest body composition and foot angle have limited relationships to functional efficiency in volleyball players.
The hamstring muscle group is the most frequently injured, representing
approximately 12 to 24% of all athletic injuries.1,2 These injuries may be due to
disproportionate training performed for the quadriceps,3 with hamstring strains
occurring more frequently in those who demonstrated hamstring weakness, and
lower hamstring-to-quadriceps strength ratios.2 Thus, hamstring strength is impor-
tant for athletic performance and injury prevention in a variety of sports.
This study examined ankle muscle activity in faster and slower basketball players during a reactive cutting task. Eighteen male basketball players completed the Y-shaped agility test while electromyography measured activity of ankle muscles. Faster players were quicker in both preferred and non-preferred cuts. For the preferred cut, only the peroneus longus on the inside cut leg showed significantly greater activity in faster players. Otherwise, ankle muscle activity did not generally differentiate faster from slower players. While ankle function is important for cutting, strength training should target all ankle muscles to support cutting demands.
This study examined the effects of fatigue on landing forces between males and females performing single leg drop landings. Five participants (3 males and 2 females) performed drop landings before and after a fatiguing exercise. Forces were measured and normalized against body weight. Males showed a smaller decrease in peak vertical force but an increase in mediolateral force compared to females after fatigue. Females showed larger decreases in all forces, suggesting decreased dynamic stability and increased risk of ACL injury when fatigued. However, kinematic analysis is still needed to understand the gender differences in joint movement.
This presentation summarizes research on the relationships between forearm girth, grip strength, thigh girth, and vertical jump height. Six subjects were measured for height, weight, forearm girth, grip strength, thigh girth, and vertical jump. Strong positive correlations were found between forearm girth and grip strength. However, a negative correlation was found between thigh girth and vertical jump height, contrary to the initial hypothesis. The results provide insights for athletes and clinicians on how to assess muscular strength and power.
Eight male subjects performed cutting maneuvers with different footwear on artificial turf to measure lower extremity forces. Peak vertical ground reaction forces were compared between football cleats and turf shoes. The only statistically significant difference was that forces on the left leg when cutting right were greater for cleats than turf shoes. While few differences were statistically significant, the study found trends such as higher forces on the push-off leg when cutting and evidence of limb dominance when running straight. Further analysis of shear forces during cutting may provide more insight into footwear effects on performance and injury risk.
This document contains assessment findings and proposed training program for a 25-year old client with anterior pelvic tilt, leg length discrepancy, foot hyperpronation, and limited range of motion. Static and functional assessments identified impairments including excessive foot pronation, weak gluteal muscles, and anterior pelvic tilt. The proposed training focuses on self-myofascial release, static stretching, isolated strengthening, and integration exercises for the feet, hips, and core to address imbalances and improve posture. Regular participation in the program was limited by the client's work commitments.
This study investigated hip muscle activation during common closed-chain rehabilitation exercises and running in runners. Electromyography was used to measure gluteus maximus and medius activation during a resisted hip external rotation exercise, single leg squat with trunk rotation, forward lunge with resisted abduction, and running. The forward lunge elicited the highest hip muscle activation, but activation was still substantially less than during running. While the exercises activated the hip muscles more than non-weight bearing exercises, there remains a disconnect between activation during exercises and running. Further research is needed to identify exercises that more closely mimic muscle demands during running.
This document discusses a study on the relationship between body composition, foot angle, and functional efficiency in volleyball boosters and smashers. The study collected data on body composition, foot angle, and variables measuring functional efficiency (e.g. vertical jump, strength) from 25 boosters and smashers. It found a significant correlation between leg strength and body composition in boosters. It also found a significant correlation between standing broad jump and foot angle in boosters. However, it found mostly insignificant correlations for smashers and between other variables. The results suggest body composition and foot angle have limited relationships to functional efficiency in volleyball players.
The hamstring muscle group is the most frequently injured, representing
approximately 12 to 24% of all athletic injuries.1,2 These injuries may be due to
disproportionate training performed for the quadriceps,3 with hamstring strains
occurring more frequently in those who demonstrated hamstring weakness, and
lower hamstring-to-quadriceps strength ratios.2 Thus, hamstring strength is impor-
tant for athletic performance and injury prevention in a variety of sports.
1) The study examined jumping and landing symmetry in 15 female gymnasts between levels 4-6.
2) Significant asymmetry was found in the gymnasts' jumping and landing performance, with the "high" leg experiencing significantly higher forces than the "low" leg.
3) Most gymnasts showed over 10% asymmetry according to clinical standards, suggesting increased injury risk, with some over 20% asymmetry.
This study investigated the preparation phase of the seated double poling cycle in sledge hockey through biomechanical analysis. A solid-static prototype representing an adult male was used with motion capture and force plates to measure kinematics and kinetics. Results showed peak impact forces occurred before 5 milliseconds post contact. Forces were greatest when preparation began slightly below the horizon. Data provides baseline measures to understand preparation phase importance and insights to improve sledge hockey performance and shoulder joint health.
This study aimed to determine which exercises best activate the gluteus medius and superior portion of the gluteus maximus muscles while minimizing activation of the tensor fascia lata muscle. Researchers used fine-wire electromyography to measure muscle activity in the gluteus medius, gluteus maximus, and tensor fascia lata muscles during 11 different exercises in 20 healthy subjects. They found that the clam exercise, sidestepping, unilateral bridging, and quadruped hip extension activated the gluteal muscles significantly more than the tensor fascia lata muscle.
NSCA National Conference (2013) Podium Presentationcoachademia
This study examined changes in medial gastrocnemius (MG) muscle-tendon interaction following 8 weeks of resistance training in 11 trained males. Following training, MG muscle elongation increased more than MG tendon elongation at hopping frequencies of 2.5 Hz and 3.0 Hz. While ankle joint strength increased, ankle joint stiffness decreased at these hopping frequencies. The results suggest that short-term resistance training disproportionately increases muscle strength relative to tendon stiffness, leading to greater reliance on the tendon during fast stretch-shortening cycle tasks.
1) The study examined electromyographic (EMG) activity in the anterior, middle, and posterior subdivisions of gluteus medius (GM) muscle during three weight-bearing exercises: wall squat, pelvic drop, and wall press.
2) The results showed significant differences in activation levels between the three GM subdivisions and between the three exercises.
3) The wall press produced the highest activation overall and was most effective at activating the posterior GM subdivision, which typically displays higher activation than the other two subdivisions.
This study examined how varying ankle stiffness affects gait and muscle activity. Healthy individuals walked on a treadmill and overground with the anklebot applying different stiffnesses. Kinematic data and electromyography of four ankle muscles were measured. Results showed that increased stiffness reduced ankle inversion/eversion range of motion while decreased stiffness increased it. Soleus muscle activity significantly increased with decreased stiffness. Walking overground produced greater ankle and knee motions than treadmill walking. Understanding how ankle stiffness impacts gait can provide insights into locomotion.
John Orchard
Adjunct Associate Professor, Sydney Medical School, University of Sydney.
-
Hamstrings are most susceptible to injury during the late stance phase of sprinting
Relationship of two vertical jumping tests to sprint and change of direction ...Isaiah McFarland
This study examined the relationship between vertical jump performance and speed/agility tests in male and female collegiate soccer players. 36 NCAA Division II soccer players (20 males and 16 females) performed countermovement jumps, squat jumps, 10m and 30m sprint tests, and change of direction speed tests. Moderate to strong correlations were found between vertical jump heights and sprint/agility performance for both males and females. The results suggest power production, as measured by vertical jumps, is related to linear speed and change of direction ability in collegiate soccer players.
This study examined the metabolic activity patterns of hamstring muscles in football players with and without a history of hamstring injuries using MRI. It found that the semitendinosus muscle had significantly higher metabolic activity than the biceps femoris and semimembranosus muscles in both groups. In players with previous injuries, metabolic activity was more symmetric across hamstring muscles compared to controls, with lower semitendinosus and higher biceps femoris activity. This suggests biceps femoris compensates for weaker semitendinosus after injury, leading to less efficient movement and increased risk of reinjury. The study concludes rehabilitation should focus on strengthening the semitendinosus muscle.
Adding stiffness to the foot through shoes and insoles during walking:
1. Decreased the amount of energy dissipated by the foot and increased the gear ratio of the foot-ankle complex.
2. Increased soleus muscle peak force production and decreased soleus fascicle shortening speed, altering the muscle's force-velocity behavior.
3. Despite changes to soleus muscle mechanics, increased whole-body metabolic cost, likely due to the added force demand placed on the plantar flexor muscles.
This study compared the impact force and knee angle between barefoot and shod runners. Six participants ran trials barefoot and shod while force and joint angle data was collected. The results found no significant difference in impact force or knee joint angle between the two running conditions. Limitations of the small participant size and use of a force plate were noted.
This document describes a biomechanical analysis of a lower limb strengthening device consisting of a harness connecting tension bands from the hips to the ankles. The analysis found that using the device increases muscle forces in the legs while improving load distribution across the knee joint. It also does not significantly increase forces on knee cartilage surfaces. The device thus has potential benefits for knee rehabilitation by strengthening muscles and joints in a balanced manner without excessive stress on cartilage.
Anthony Shield - is nmi a risk factor for hamstring strain injury MuscleTech Network
Anthony Shield
Senior lecturer, School of Exercise and Nutrition Science Institute of Health and Biomedical Innovation Queensland University of Technology, Brisbane, Australia.
-
Is neuromuscular inhibition a risk factor for hamstring strain?
This study examined muscle activation patterns in the lower extremities during different squat techniques. 28 healthy subjects performed squats with neutral alignment (control), intentional frontal plane malalignment (medial knee displacement), and sagittal plane malalignment (anterior knee displacement). Electromyography was used to measure muscle activation in the quadriceps, hamstrings, and gastrocnemius. Results showed altered muscle activation patterns during the malaligned squats, with decreased quadriceps activation during medial knee displacement and changes in quadriceps and hamstring activation timing during anterior knee displacement compared to the control squat. The study provides information on how muscle activation changes with different squat alignments.
Knee strenght after total knee arthroplastyFUAD HAZIME
1) Knee strength was measured in 52 healthy control knees and 32 knees more than 2 years after total knee arthroplasty (TKA).
2) On average, isometric extension peak torque values in TKA patients were reduced by up to 30.7% compared to controls. Isometric flexion peak torque values in TKA patients were on average 32.2% lower than controls.
3) Relatively greater quadriceps strength in TKA patients was associated with better Knee Society Functional Scores, while a higher hamstring to quadriceps ratio was associated with worse scores. Older and more overweight TKA patients also had lower strength.
Anthony Shield - does strength in the nhe predict hamstring injury MuscleTech Network
Anthony Shield
Senior lecturer, School of Exercise and Nutrition Science Institute of Health and Biomedical Innovation Queensland University of Technology, Brisbane, Australia.
-
Does strength in the Nordic hamstring exercise predict hamstring injury?
(&th MuscleTech Network workshop)
14th October, Barcelona
Laudner kajiyama the relationship between anterior gh laxity and propriocepti...Satoshi Kajiyama
This study examined the relationship between anterior glenohumeral laxity and proprioception in 30 asymptomatic collegiate baseball players. Anterior glenohumeral laxity was measured using an arthrometer and proprioception was assessed by measuring active joint position sense at various shoulder rotations. Linear regression analyses showed no relationship between anterior laxity and proprioception at 30 degrees of internal and external rotation. However, there was a moderate positive relationship between anterior laxity and proprioception at 75 degrees of external rotation, suggesting that proprioception decreases as anterior laxity increases at this position.
This study examined the effects of statin use on functional mobility and flexibility in 16 healthy masters swimmers aged 55-75 years old, with 7 taking statins and 9 not taking statins. While most functional mobility tests showed no significant differences, the statin group had significantly less shoulder flexibility compared to the non-statin group. As expected, total cholesterol and LDL levels were significantly lower in the statin group, confirming the drugs' effectiveness in lowering cholesterol. The authors concluded that while statins lower cholesterol, they may adversely impact flexibility, especially in the extremities.
Lorelei Scionti has over 25 years of experience in administrative assistance, project management, data entry, and quality assurance. She has a track record of developing efficient systems to improve workflows and reduce costs. Her most recent roles include providing animal care at a humane society shelter and serving as a training coordinator for the US Air Force, where she achieved high attendance rates and reduced training backlogs and errors. She holds a BA in Spanish and History from UMass Dartmouth.
El documento describe las principales instituciones administrativas del trabajo en Venezuela. Brevemente:
1) El Ministerio del Poder Popular para el Trabajo es el encargado de la materia laboral y de aplicar la legislación laboral.
2) Las Inspectorías del Trabajo tramitan procedimientos laborales por la vía administrativa e inspeccionan entidades.
3) Las Procuradurías defienden a trabajadores con salarios bajos en instancias administrativas y judiciales.
1) The study examined jumping and landing symmetry in 15 female gymnasts between levels 4-6.
2) Significant asymmetry was found in the gymnasts' jumping and landing performance, with the "high" leg experiencing significantly higher forces than the "low" leg.
3) Most gymnasts showed over 10% asymmetry according to clinical standards, suggesting increased injury risk, with some over 20% asymmetry.
This study investigated the preparation phase of the seated double poling cycle in sledge hockey through biomechanical analysis. A solid-static prototype representing an adult male was used with motion capture and force plates to measure kinematics and kinetics. Results showed peak impact forces occurred before 5 milliseconds post contact. Forces were greatest when preparation began slightly below the horizon. Data provides baseline measures to understand preparation phase importance and insights to improve sledge hockey performance and shoulder joint health.
This study aimed to determine which exercises best activate the gluteus medius and superior portion of the gluteus maximus muscles while minimizing activation of the tensor fascia lata muscle. Researchers used fine-wire electromyography to measure muscle activity in the gluteus medius, gluteus maximus, and tensor fascia lata muscles during 11 different exercises in 20 healthy subjects. They found that the clam exercise, sidestepping, unilateral bridging, and quadruped hip extension activated the gluteal muscles significantly more than the tensor fascia lata muscle.
NSCA National Conference (2013) Podium Presentationcoachademia
This study examined changes in medial gastrocnemius (MG) muscle-tendon interaction following 8 weeks of resistance training in 11 trained males. Following training, MG muscle elongation increased more than MG tendon elongation at hopping frequencies of 2.5 Hz and 3.0 Hz. While ankle joint strength increased, ankle joint stiffness decreased at these hopping frequencies. The results suggest that short-term resistance training disproportionately increases muscle strength relative to tendon stiffness, leading to greater reliance on the tendon during fast stretch-shortening cycle tasks.
1) The study examined electromyographic (EMG) activity in the anterior, middle, and posterior subdivisions of gluteus medius (GM) muscle during three weight-bearing exercises: wall squat, pelvic drop, and wall press.
2) The results showed significant differences in activation levels between the three GM subdivisions and between the three exercises.
3) The wall press produced the highest activation overall and was most effective at activating the posterior GM subdivision, which typically displays higher activation than the other two subdivisions.
This study examined how varying ankle stiffness affects gait and muscle activity. Healthy individuals walked on a treadmill and overground with the anklebot applying different stiffnesses. Kinematic data and electromyography of four ankle muscles were measured. Results showed that increased stiffness reduced ankle inversion/eversion range of motion while decreased stiffness increased it. Soleus muscle activity significantly increased with decreased stiffness. Walking overground produced greater ankle and knee motions than treadmill walking. Understanding how ankle stiffness impacts gait can provide insights into locomotion.
John Orchard
Adjunct Associate Professor, Sydney Medical School, University of Sydney.
-
Hamstrings are most susceptible to injury during the late stance phase of sprinting
Relationship of two vertical jumping tests to sprint and change of direction ...Isaiah McFarland
This study examined the relationship between vertical jump performance and speed/agility tests in male and female collegiate soccer players. 36 NCAA Division II soccer players (20 males and 16 females) performed countermovement jumps, squat jumps, 10m and 30m sprint tests, and change of direction speed tests. Moderate to strong correlations were found between vertical jump heights and sprint/agility performance for both males and females. The results suggest power production, as measured by vertical jumps, is related to linear speed and change of direction ability in collegiate soccer players.
This study examined the metabolic activity patterns of hamstring muscles in football players with and without a history of hamstring injuries using MRI. It found that the semitendinosus muscle had significantly higher metabolic activity than the biceps femoris and semimembranosus muscles in both groups. In players with previous injuries, metabolic activity was more symmetric across hamstring muscles compared to controls, with lower semitendinosus and higher biceps femoris activity. This suggests biceps femoris compensates for weaker semitendinosus after injury, leading to less efficient movement and increased risk of reinjury. The study concludes rehabilitation should focus on strengthening the semitendinosus muscle.
Adding stiffness to the foot through shoes and insoles during walking:
1. Decreased the amount of energy dissipated by the foot and increased the gear ratio of the foot-ankle complex.
2. Increased soleus muscle peak force production and decreased soleus fascicle shortening speed, altering the muscle's force-velocity behavior.
3. Despite changes to soleus muscle mechanics, increased whole-body metabolic cost, likely due to the added force demand placed on the plantar flexor muscles.
This study compared the impact force and knee angle between barefoot and shod runners. Six participants ran trials barefoot and shod while force and joint angle data was collected. The results found no significant difference in impact force or knee joint angle between the two running conditions. Limitations of the small participant size and use of a force plate were noted.
This document describes a biomechanical analysis of a lower limb strengthening device consisting of a harness connecting tension bands from the hips to the ankles. The analysis found that using the device increases muscle forces in the legs while improving load distribution across the knee joint. It also does not significantly increase forces on knee cartilage surfaces. The device thus has potential benefits for knee rehabilitation by strengthening muscles and joints in a balanced manner without excessive stress on cartilage.
Anthony Shield - is nmi a risk factor for hamstring strain injury MuscleTech Network
Anthony Shield
Senior lecturer, School of Exercise and Nutrition Science Institute of Health and Biomedical Innovation Queensland University of Technology, Brisbane, Australia.
-
Is neuromuscular inhibition a risk factor for hamstring strain?
This study examined muscle activation patterns in the lower extremities during different squat techniques. 28 healthy subjects performed squats with neutral alignment (control), intentional frontal plane malalignment (medial knee displacement), and sagittal plane malalignment (anterior knee displacement). Electromyography was used to measure muscle activation in the quadriceps, hamstrings, and gastrocnemius. Results showed altered muscle activation patterns during the malaligned squats, with decreased quadriceps activation during medial knee displacement and changes in quadriceps and hamstring activation timing during anterior knee displacement compared to the control squat. The study provides information on how muscle activation changes with different squat alignments.
Knee strenght after total knee arthroplastyFUAD HAZIME
1) Knee strength was measured in 52 healthy control knees and 32 knees more than 2 years after total knee arthroplasty (TKA).
2) On average, isometric extension peak torque values in TKA patients were reduced by up to 30.7% compared to controls. Isometric flexion peak torque values in TKA patients were on average 32.2% lower than controls.
3) Relatively greater quadriceps strength in TKA patients was associated with better Knee Society Functional Scores, while a higher hamstring to quadriceps ratio was associated with worse scores. Older and more overweight TKA patients also had lower strength.
Anthony Shield - does strength in the nhe predict hamstring injury MuscleTech Network
Anthony Shield
Senior lecturer, School of Exercise and Nutrition Science Institute of Health and Biomedical Innovation Queensland University of Technology, Brisbane, Australia.
-
Does strength in the Nordic hamstring exercise predict hamstring injury?
(&th MuscleTech Network workshop)
14th October, Barcelona
Laudner kajiyama the relationship between anterior gh laxity and propriocepti...Satoshi Kajiyama
This study examined the relationship between anterior glenohumeral laxity and proprioception in 30 asymptomatic collegiate baseball players. Anterior glenohumeral laxity was measured using an arthrometer and proprioception was assessed by measuring active joint position sense at various shoulder rotations. Linear regression analyses showed no relationship between anterior laxity and proprioception at 30 degrees of internal and external rotation. However, there was a moderate positive relationship between anterior laxity and proprioception at 75 degrees of external rotation, suggesting that proprioception decreases as anterior laxity increases at this position.
This study examined the effects of statin use on functional mobility and flexibility in 16 healthy masters swimmers aged 55-75 years old, with 7 taking statins and 9 not taking statins. While most functional mobility tests showed no significant differences, the statin group had significantly less shoulder flexibility compared to the non-statin group. As expected, total cholesterol and LDL levels were significantly lower in the statin group, confirming the drugs' effectiveness in lowering cholesterol. The authors concluded that while statins lower cholesterol, they may adversely impact flexibility, especially in the extremities.
Lorelei Scionti has over 25 years of experience in administrative assistance, project management, data entry, and quality assurance. She has a track record of developing efficient systems to improve workflows and reduce costs. Her most recent roles include providing animal care at a humane society shelter and serving as a training coordinator for the US Air Force, where she achieved high attendance rates and reduced training backlogs and errors. She holds a BA in Spanish and History from UMass Dartmouth.
El documento describe las principales instituciones administrativas del trabajo en Venezuela. Brevemente:
1) El Ministerio del Poder Popular para el Trabajo es el encargado de la materia laboral y de aplicar la legislación laboral.
2) Las Inspectorías del Trabajo tramitan procedimientos laborales por la vía administrativa e inspeccionan entidades.
3) Las Procuradurías defienden a trabajadores con salarios bajos en instancias administrativas y judiciales.
This document provides information about mass trauma packs available to Region 1 agencies for large-scale incidents. It discusses the need for aggressive bleeding control and rapid intervention at dynamic scenes. The packs contain tourniquets, dressings, chest seals, blankets, and litters to help control hemorrhaging within the C-TECC framework of threat suppression, hemorrhage control, rapid extrication, assessment, and transport. Proper use of these equipment can help save lives by controlling bleeding within the crucial 3 minute window.
Mahamadrafi N. Saiyad has over 10 years of experience in production planning, scheduling, inventory management, and supervision. He is currently a Senior Engineer of Production Planning at Shreenathji Engineering Co. in V.U. Nagar, Gujarat. Prior to this role, he held production planning and engineering positions at several manufacturing companies in Gujarat, including Elecon Engineering Co., Fluidline Valves Co., and Reliance Engineering Associates. He has expertise in production planning, scheduling, manufacturing processes, inventory management, and manpower planning.
This document contains personal and educational details of Rahul Kr Shaw, including his permanent and temporary addresses, contact information, objective, academic qualifications, training experience, skill set, languages known, areas of interest, and declaration. It summarizes his Bachelor of Technology degree in Civil Engineering from Budge Budge Institute of Technology, West Bengal, skills in computer programming languages like Java and C, and interest in reading, music, cricket and painting.
The document provides a summary of an individual's work experience and qualifications. It lists the applicant's employment history from 2014 to 1996 including roles as a heavy equipment mechanic and marine mechanic. Responsibilities in these roles involved troubleshooting, repairing, and overhauling various heavy machinery and engines. The applicant also provides personal details and education information.
Lorelei Scionti seeks a service department coordinator position. She has over 25 years of experience in project management, administration, data entry, and quality assurance. Most recently, she worked as an animal care provider and volunteer for the Humane Society and Shelter South Coast. Prior to that, she spent over 25 years in the United States Air Force where she held several roles including training program coordinator, operations manager, crew chief, and hydraulics technician. She has a proven track record of improving efficiency, reducing costs and errors, and ensuring compliance.
El documento describe la evolución de la tecnología y su impacto en la vida humana a través de la historia. El hombre primitivo utilizó herramientas de piedra y madera para satisfacer sus necesidades básicas de alimento y refugio, y con el tiempo desarrolló la agricultura, la ganadería y la metalurgia. La tecnología moderna ha cambiado significativamente la forma de vida de las personas y ha traído tanto beneficios como desafíos ambientales.
El documento describe la organización de los tribunales laborales en Venezuela. Está dividido en dos instancias: tribunales superiores en primera instancia y tribunales superiores en segunda instancia. En la primera instancia están los tribunales de sustanciación, mediación y ejecución del trabajo y los tribunales de juicio del trabajo. En la segunda instancia están los tribunales superiores del trabajo y el Tribunal Supremo de Justicia en sala de casación social.
Este documento describe los objetivos y contenidos de la selección de cojinetes de rodamientos. Explica que los cojinetes sirven para apoyar ejes y árboles que giran, y pueden ser de deslizamiento o de rodamiento. También describe los elementos que componen los cojinetes de rodamiento, como bolas, aros, jaulas, sellos y lubricantes. Finalmente, detalla el proceso para seleccionar el cojinete adecuado según las cargas y especificaciones requeridas.
Lorelei Scionti has over 25 years of experience in project management, customer support, and aircraft maintenance. She has a track record of developing efficient systems to improve processes and reduce costs. Her resume highlights skills in organization, compliance, attention to detail, project tracking, and data management. Scionti held several leadership roles in the Air Force where she coordinated training programs, managed maintenance schedules, and ensured aircraft safety and mission readiness. More recently, she has worked in animal care positions at a local humane society shelter.
This document is an architecture portfolio belonging to Sean Qing Xiaolin. It contains documentation of design projects including a pedestrian bridge connecting two landmarks in Newcastle, a railway interchange building in Manors, and case studies of listed buildings. It also includes sketches and photographs illustrating important architectural aspects. The portfolio demonstrates Sean's interest in exploring the relationship between architecture, culture, and users through both analytical case studies and creative design projects.
The Royce Code promises immediate profits of $1,500 within 3 hours of signing up through their automated trading software. However, the review finds the website lacks basic details and the CEO's identity is fake, having been used in previous scams. While online trading can be legitimate, this program is likely a scam as it demands an upfront payment of $250 and promises unrealistic profits without explaining how the trading works. The review recommends avoiding this program and using only licensed platforms.
Richard Joralmon has over 15 years of experience leading military medical clinics with annual budgets ranging from $2.2 million to $38 million. He has successfully led clinics through Joint Commission surveys with no deficiencies. As Director of various clinics, he improved access to care through appointment scheduling changes and standardization of exam rooms, resulting in increased productivity and available appointments. He also developed initiatives to decrease wait times for specialty services. Joralmon has advanced degrees in health sciences, public administration, and dentistry.
Jurgen Put is a Global Category Manager at Nokia responsible for defining cybersecurity and IoT strategy. He has over 20 years of experience in procurement and R&D project management. He holds a degree in Industrial Engineering from KU Leuven and is fluent in Dutch, English, and proficient in French. Prior to his current role, he held various procurement positions at Alcatel and Nokia, managing suppliers and commodity categories globally. He has also worked in R&D managing testing projects and as a service engineer.
This document provides a summary of Ghandi MohammadMousaAl Bakkar's professional experience and qualifications. It outlines his extensive experience managing programs for refugees and displaced people in Jordan, including over $8 million in grants. It also details his experience developing training programs, materials, and strategies in areas like child protection, early childhood development, career counseling, and life skills. A variety of qualifications are listed, including education in sociology and chemical engineering, as well as language skills in Arabic and English.
The document introduces a group of students from the village of Krokos in Greece. Krokos has around 5,000 residents and is known for cultivating saffron, which the village is named after. Saffron is harvested each autumn and is considered one of the highest quality varieties worldwide. The major economic activity of Krokos is saffron cultivation, and the spice is widely used in local cooking. The village has several cultural and educational institutions that promote the local way of life.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
El documento describe los principales símbolos patrios del Perú: la bandera, el escudo y el himno nacional. La bandera peruana data de 1825 y consiste en tres franjas verticales roja, blanca y roja. El escudo también se estableció en 1825 y representa las riquezas del Perú a través de la vicuña, la quina y la cornucopia. El himno nacional fue adoptado en 1822 y es considerado uno de los himnos más hermosos del mundo junto con la Marsellesa francesa.
663229 - Reliability of Power Output in Single Leg Counter Movement Jump in E...Sergio Gaggioni
This document summarizes a study that assessed the reliability of using single leg countermovement jumps (CMJs) to measure power output in elite rugby players. Twenty professional rugby players performed 3 maximal single leg CMJs with each leg. Power output was measured using a force platform. Results showed excellent reliability for power output measurements between jumps, with intraclass correlation coefficients of 0.963-0.974 for left and right legs. Power output was similarly reliable when comparing forwards and backs, suggesting single leg CMJs could reliably measure limb asymmetries and be used to assess an athlete's readiness to return to play following injury. However, further research is needed to address limitations like jumping form.
1) The study examined the effects of different heel lift heights (0.64 cm, 1.27 cm, 2.54 cm, 3.18 cm) on back squat performance and biomechanics in one male participant.
2) Preliminary results found that trunk lean was lowest at heel heights above 0.64 cm, suggesting weightlifting shoes with heels over 0.64 cm may reduce risk of back injury during squats.
3) Increasing heel height reduced ankle range of motion but increased peak ankle flexion, indicating a more vertical shank position conducive to proper squat form. Knee displacement did not significantly change with heel height.
This document examines how experience level of experimenters placing markers for multi-segment foot kinematic analysis affects the reliability of the results. Three experimenters with different levels of experience (experienced, intermediate, novice) placed markers on 12 participants on two occasions. Kinematic data of the foot segments during walking were analyzed within and between experimenters. The results showed significant differences between experimenters and within the novice experimenter for several discrete kinematic parameters. Reliability as measured by ICCs was highest for the experienced experimenter and lowest or absent for the novice experimenter, suggesting experimenter experience impacts reliability of multi-segment foot kinematic data.
Poster: Knee Control as a Risk Factor for Injury in Youth Soccer. Anu RäisänenUKK-instituutti
Poster by researcher Anu Räisänen in CASEM’s Annual Sport Medicine Symposium in Halifax, Canada on June 6-9, 2018. Poster was presented by assistant professor Kati Pasanen.
Poster: Examining knee control as a risk factor for non-contact lower extremity injury: A prospective study in youth soccer
Research Group: Anu M Räisänen, Hillevi Arkkila, Tommi Vasankari, Kathrin Steffen, Jari Parkkari, Pekka Kannus, Hannele Forsman, Kati Pasanen
Tampere Research Center of Sport Medicine, UKK Institute, Finland
1) Bilateral and unilateral isometric squat strength assessments were reliable measures for youth athletes and improved with maturation. Bilateral strength predicted change-of-direction (COD) performance over short distances, while unilateral strength predicted longer COD courses.
2) Acute turn-around time (4mTAT) was useful for assessing COD performance but not as a standalone test. As maturation and COD course distances increased, correlations between COD performance and isometric strength also increased.
3) Researchers examined relationships between isometric squat strength, COD performance, and maturation in youth athletes over different COD course lengths and distances. Bilateral and unilateral strength improved with maturation and better predicted longer COD courses.
LOWER LIMB ANGULAR KINEMATICS AND HOW IT EFFECTS GAIT SPEEDJohn Joe Magee
This study examined the relationship between lower limb angular kinematics and gait speed. The researcher measured peak knee flexion in the stance and swing phases and peak plantarflexion in a participant walking at various speeds. Results showed no significant correlation between knee flexion in stance and speed. However, there was a strong positive correlation between knee flexion in swing and speed, as well as between plantarflexion and speed. These findings support previous research indicating that knee flexion in swing and plantarflexion are important mechanisms for achieving higher gait velocities.
The study assessed the validity and reliability of the Myotest Pro wireless accelerometer for measuring muscular force during countermovement jumps. 48 subjects performed countermovement jumps on a force plate and while wearing the accelerometer on two separate occasions. The accelerometer showed high correlation with the force plate but overestimated force production by 7.8%. Both devices demonstrated good reliability. However, the accelerometer's calculation method that treats mass as constant may overestimate force values compared to the force plate, as lifting of the lower leg during the jump causes mass to vary.
The document discusses a study that tested whether a Constant Force Resistive Exercise Unit (CFREU) machine could maintain muscle strength over 10 weeks as effectively as free weights. 9 subjects were split into CFREU and free weight groups and performed leg exercises 3 times per week. The CFREU group saw significantly greater improvements in strength gains compared to the free weight group. The results suggest the CFREU machine was as effective or possibly more effective than free weights at maintaining muscle strength over time.
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A Comparative Study of the Clinical and Functional Outcome Anterior Cruciate ...TheRightDoctors
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This randomized controlled trial examined the effects of two modified posterior shoulder stretching exercises (PSSEs) on shoulder mobility, pain, and dysfunction in patients with subacromial impingement syndrome (SIS). 67 patients with SIS and internal rotation deficit were assigned to receive either a modified cross-body stretch, modified sleeper stretch, or a control treatment of modalities and exercises without PSSEs. Both stretching groups demonstrated greater improvements in pain with activity, internal rotation range of motion, function, and disability compared to the control group. However, there was no significant difference between the two stretching groups. All treatments led to improvements in pain, shoulder mobility, function, and disability.
This document summarizes several studies related to foot and ankle research. It highlights studies on muscle strength in patients with gout, muscle and joint factors associated with foot deformities in diabetics, the effectiveness of extracorporeal shock wave therapy for lower limb tendinopathies, and multidisciplinary management of diabetic foot disease. It also reviews evidence on treatments for plantar heel pain and vascular assessment techniques used by podiatrists. The introduction provides an overview of various foot and ankle conditions and clinical factors considered by clinicians in lower limb rehabilitation.
This study examined the effects of a 6-week isokinetic resistance training program on quadriceps and hamstrings peak torque and standing long jump performance in 12 untrained men. The training consisted of 3 sets of 10 repetitions at 100°/s, 3 days per week for 6 weeks. After training, quadriceps peak torque increased by an average of 10.5% but there was no significant change in hamstrings peak torque or standing long jump performance. The major finding was that gains in isokinetic strength did not translate to improvements in functional performance, likely due to the training lacking eccentric loading which is an important component of the standing long jump.
This study compared the placement of a counterforce brace for treating lateral epicondylitis (tennis elbow) in two positions: directly over the origin of the extensor carpi radialis brevis muscle or in the customary position over the proximal forearm. Seven participants performed various activities while surface electromyography measured muscle activity. Results showed stronger grip strength with the customary proximal forearm placement, but more advantageous muscle activity patterns with the origin placement. The study suggests the origin placement is more beneficial but a larger sample size is needed to definitively conclude effectiveness.
Changes During Passive Recovery In Lower Limbs Tiredness After Strenuous WorkoutIOSR Journals
Abstract: Lower limbs tiredness is a widely accepted indicator for recovery state prediction. The study was
designed and purposed to know the rate and trend of lower limbs tiredness recovery after strenuous workout in
passive state. Ten athletes from LNIPE, Gwalior having almost similar anthropometric measurements,
physiological capacity, chronological age(18-19 year), training age(5-6 year), event(sprinters) etc. residing in
same campus having similar daily routine were selected as participant in this experiment. The experiment was
conducted in a highly controlled environment using sophisticate equipments. Target Heart Rate Zone of the
workout lasting for 20 minutes was 80%-90% of their Maximum Heart Rate. Three readings including pre, post
and 30 minutes post workout was considered for both the two tests (Isometric Leg Strength Test and Sergeant
Jump Test) selected for the purpose. rANOVA was employed separately to derive out meaningful information
from the raw data. In both the tests well controlled workout for 20 minutes resulted in significant increase state
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promote lower limbs tiredness recovery during this post recovery period.
Keyword: Isometric Leg Strength Test, Sergeant Jump Test, Recovery, rANOVA
1) The study examined whether previous ballistic or dynamic conditioning contractions could enhance subsequent throwing performance in competitive rugby players.
2) The results showed that a ballistic conditioning contraction significantly improved maximum displacement and velocity in the subsequent throw, while both ballistic and dynamic contractions significantly improved peak velocity and velocity at peak power.
3) The findings indicate that ballistic activity can improve aspects of throwing performance related to velocity and distance, while dynamic and ballistic contractions can both enhance velocity.
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Test-retest reliability of a standing isometric hamstring bridge test using force platforms to
examine isometric peak hamstring force in the dominant vs non-dominant leg
Introduction
Hamstring strains are common in a number of sports, most notably invasions games such as
football, where dynamic movements such as jumping and sprinting are frequent. In an
epidemiological study by Cohen et al (2011), the average number of training sessions and games
missed through hamstring strains were 11.3 and 2.6 respectively over a ten year period, with the
number of games missed ranging from 0-16 across the 39 subjects. A number of factors affect the
amount of time spent on the side-lines, including the player’s age, injury history and the grade of
the injury, which over a season and within a large squad of players represents a major disadvantage
for a sports team. Muscle strains have a high rate of recurrence (Orchard, Best and Verrall, 2005)
often due to incomplete rehabilitation through returning to play too quickly. As such, reliably
assessing the ability of the player to safely return to play is crucial for reducing the recurrence rate
and improving player availability over the entire season. One such way of assessing muscle
damage and readiness to return to play is by measuring isometric peak hamstring force (IPHF).
Whilst accurate measures of IPHF can be obtained using an isokinetic dynamometer, the
equipment is expensive and lack portability. Isometric contractions has been proven to be a safer
modality for reporting peak force than eccentric contractions, due to its little or no structural
muscle damage in comparison (Nosaka, Newton and Sacco, 2002). McCall et al (2015) presented
two simple tests that produced reliable measures of IPHF that could be implemented in
significantly less time and in a field setting. The method involved subjects lying supine in two
conditions; a) with the hip at 90° (from full hip extension) and the foot resting on a force platform,
raised to elicit a knee angle of 90° (from full knee extension); or b) with the knee at 30° and hip
angle at 30°. During a 3 second contraction, the coefficient of variation for IPHF in both dominant
and non-dominant legs for both tests, were reported as lower than the 10% cut-off used to declare
reliability. However, it was suggested that the force produced during this test may have been
influenced by activation of the hip extensor muscles which would incorrectly reflect IPHF. This
problem was also experienced during pilot testing of a similar supine protocol from our group,
with subjects facing difficulty resisting hip extension. Standing upright as opposed to lying supine
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may limit the extent of hip extension and as such, provide a more accurate assessment of IPHF,
whilst maintaining the quick and easy to administer characteristics of the former test. Therefore,
the aim of the study was to investigate the test-retest reliability of a standing isometric hamstring
test reporting IPHF.
Methods
Subjects Characteristics
Six subjects (five male, one female) working at St George's Park completed the study. All subjects
completed the IPHF testing at least 1 week prior to testing in order to familiarise themselves with
the protocol. All subjects reported a healthy state on the day of testing with no previous lower limb
injuries.
Protocol
Subjects were required on two separate days, separated by 24 hours, for testing and retesting with
the same protocol used on each day. Subjects completed a standardised warm up at 80-90 watts on
a watt-bike for five minutes. Following a five minute rest, testing began. Subjects placed their
dominant leg on a zeroed force plate (Pasco Scientific, Inc. Roseville, CA, USA, PS-2141), which
was attached to a flat, solid board ratcheted to couch that could be adjusted for height and
proximity. With their foot placed in the centre of the force plate, the couch was adjusted until hip
angle was at 90° and knee angle was at 20° from full extension. An allowance of 5° either side
was given. Angles were measured using a handheld goniometer. To calculate force production
relative to leg mass, the leg to be worked was weighed upon the force plate. The subjects were
instructed to stand with the head, upper back, buttocks and heel flat against the wall and their arms
across their chest. In order to fully activate the hamstring muscles, after a three second countdown
the subjects were instructed to push down on the platform through the heel, by attempting to curl
their heel back towards the wall for three seconds. Following the effort, subjects were allowed to
surrender the hamstring bridge position and rest for two minutes before completing the next two
trials in order to negate the effects of fatigue on force production. For the repeated efforts, the foot
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was placed again on the centre of the platform and the trials completed without re-measurement
of angles to replicate the field testing procedure. Following completion of the dominant leg, the
non-dominant leg underwent the same test and within a week the testing protocol was repeated
again to determine test-retest reliability. During each trial, isometric peak force was recorded along
with the rate of force development (RoFD) at 100, 150 and 200ms.
Statistical Analysis
A Shapiro-Wilk test was used to test the data for normal distribution, with a paired sample t-test
used to test for differences between the test and retest averages for the dominant and non-dominant
legs. Significance was set at p < 0.05. A spreadsheet by Hopkins (2002) was used to determine the
change in mean (CIM) between the test and retest trials, the typical error of measurement (TE) and
the intraclass correlation coefficient (ICC) at 90% confidence limits. The minimal difference need
to be considered as real (MD) was calculated as (TE x 1.96) x √2 (Weir, 2005). The limits of
agreement for IPHF were calculated in SPSS (SPSS 22.0) and plotted using the Bland-Altman
method. Effect sizes for normally distributed between test comparisons were calculated using
Cohen’s d.
Results
Dominant and non-dominant IPHF and RoFD were reported as normally distributed. Following
paired sample t-tests, no significant difference was reported in dominant and non-dominant IPHF
respectively, results of which are shown in Table 1. Paired sample t-tests were also ran for the
RoFD for the non-dominant leg at 100ms, 150ms and 200ms respectively (t = -.232, p = .826; ES
= -0.03; t = -.138, p = .896; ES = -0.02; t = .073; p = .945; ES = -0.02). RoFD for the dominant
leg was also reported as normally distributed, with no significantly difference reported for
100ms, 150ms and 200ms respectively (t = -1.730, p = .144; ES = -0.21; t = -.700, p = .515; ES =
-0.07; t = -.551, p = .605; ES = -0.07). All effect sizes were reported as small. Table 2 presents
the reliability variables for IPHF (typical error, change in mean, intraclass coefficient and
minimal difference) of the tests performed on the force plate. Tables 3 and 4 present the same
reliability variables for RoFD of the dominant and non-dominant legs of the test respectively.
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Table 1. t-test means, standard deviations, effect sizes and the magnitude of the effect sizes for
dominant and non-dominant IPHF.
Table 2. Reliability of simple and quick test for isometric peak hamstring force in standing
subjects.
Note: TE - typical error of measurement; ICC – intraclass correlation coefficient; MD - minimal
difference.
Table 3. Reliability of simple and quick test for rate of force development in dominant leg of
standing subjects.
Table 4. Reliability of simple and quick test for rate of force development in non-dominant leg
of standing subjects.
A Bland-Altman Plot was used to determine the limits of agreement for the IPHF in the
dominant and non-dominant legs (Bland and Altman, 1986). Data points lying between these two
lines indicate good test-retest reliability. Figures 1 and 2 show the test-retest averages for each
IPHF t -test ES ES Magnitude Mean Std.Deviation
Dominant -2.123; p = -0.087 -0.11 Small -9.51 10.97
Non-Dominant -2.195; p = 0.080 -0.12 Small -11.8 13.17
TE (90% CL) Change in mean (90% CL) ICC (90% CL) MD
RoFD at 100ms (N/ms) 46.96 (31.56 - 98.12) 46.91 (-7.73 - 101.55) 0.92 (0.67 - 0.98) 130.17
RoFD at 150ms (N/ms) 37.46 (25.18 - 78.26) 15.14 (-28.44 - 58.72) 0.99 (0.93 - 1.0) 103.8
RoFD at 200ms (N/ms) 40.36 (27.12 - 84.31) 12.84 (-34.11 - 59.79) 0.98 (0.89 - 0.99) 111.85
TE (90% CL) Change in mean (90% CL) ICC (90% CL) MD
Dominant Leg Test (N) 7.76 (5.22 - 16.22) 9.52 (0.48 - 18.55) 0.99 (0.95 - 1.0) 21.51
Non-Dominant Leg Test (N) 9.31 (6.26 - 19.46) 11.80 (0.97 - 22.63) 0.99 (0.94 - 1.0) 25.81
TE (90% CL) Change in mean (90% CL) ICC (90% CL) MD
RoFD at 100ms (N/ms) 83.15 (55.88 - 173.73) 11.15 (-85.59 - 107.89) 0.93 (0.71 - 0.98) 230.49
RoFD at 150ms (N/ms) 65.87 (44.27 - 137.62) 5.25 (-71.38 - 81.88) 0.93 (0.70 - 0.98) 182.6
RoFD at 200ms (N/ms) 70.66 (47.49 - 147.62) -2.99 (-85.19 - 79.22) 0.87 (0.46-0.96) 195.9
Table 4. Reliability of simple and quick test for rate of force development in non- dominant leg of standing participants.
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subject plotted against the test-retest difference and the subsequent limits of agreement. See
appendices for RoFD and corresponding limits of agreement (Figures 3-8).
Figure 1. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for IPHF in the dominant leg. Note: SD = standard deviation
Figure 2. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for IPHF in the non-dominant leg. Note: SD = standard deviation.
- 1.96 SD
-29.2
Mean
-9.51
+ 1.96 SD
10.1
+ 1.96 SD
11.76
Mean
-11.8
- 1.96 SD
-35.36
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Mean and limits of agreement were used to determine the range of the test-retest difference for
both the dominant and non-dominant IPHF; the results of which are shown below in Table 5.
Table 5. Mean difference, upper and lower limits of agreement and the range of both dominant
and non-dominant isometric peak hamstring force.
Discussion
The primary aim of this study was to investigate the test-retest reliability of a standing hamstring
bridge test. To the best of our knowledge, this is the first study to examine this body position and
the results have been encouraging. Throughout testing, this novel method proved to be quick and
easy to administer, making it suitable for application within a practical setting. The IPHF values
recorded were not only highly correlated but also fell between the upper and lower limits of
agreements in both dominant and non-dominant legs.
The range difference between the upper and lower limits of agreement was 39.3N and 47.1N
respectively. In relation to the average means across the subjects, this represented a variance
equating to almost 16% of their average maximal effort (249N). A similar hamstring test by
McCall et al (2015) showed a mean difference of 11-16%,although this study focused on simulated
match fatigue. This study reported IPHF in a supine position as a useful tool for measuring
isometric force reductions in professional football players. Limits of agreement will differ
between studies but the range of difference between test and re-test averages of the McCall study
were consistent with the present study. A difference between 38N and 54N was recorded, although
this study was completed by professional French Ligue 1 football players so it can be expected
that their results would be more consistent than the recreationally active subjects used in the
present study.
IPHF Mean Difference Upper Limit Lower Limit Range
Dominant (N) -9.52 10.13 -29.16 39.3
Non-Dominant (N) -11.8 11.76 -35.36 47.1
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One key question to arise from this statement is whether this represents a justifiable and reliable
difference between trials for subjects. A possible reason for this high, but nonetheless reliable
fluctuation exists regarding the technique adopted by the subjects. Prior to testing, a pilot study
was carried out which highlighted a number of issues regarding the technique used to produce
force, such as hip extension, heel placement and arm position. This hip extension and subsequent
change in hip angle allowed for an increase in vertical force when compared with the original test
measures. For example, one subject exhibited an IPHF equal or greater than another subject despite
a noticeable difference in body type and limb length. Although anthropometry cannot be discarded
so easily, the results from this pilot study showed vast differences between test and retest trials
which correlated with an ever-changing technique adopted. Although these issues were resolved
in the present study, it remains important to continue enforcing strict coaching cues to remove
inconsistencies in technique and improve reliability. Furthermore, it is possible that the element of
competition, with the aim of beating previous scores or attempting to increase magnitude of the
force trace displayed to the subjects, influenced the subjects into producing force by any means
necessary, at the expense of correct form. Therefore in the present study, subjects were blinded to
their own and others’ scores and were unable to view the force trace until the test-retest protocol
has been completed in both legs.
Another noteworthy finding is that the majority of the subject test-retest averages fell between the
mean and lower limit of agreement, suggesting a fatiguing effect during trials. Each subject
completed three trial on each leg during both test and retest trials, with a two minute rest period
implemented between each trial. Verbal dialect with subjects during testing revealed a fatiguing
effect existing, with three subjects reporting tightness in their hamstrings, and another commenting
on the uncomfortable starting position for the IPHF recording. While the latter issue was removed
via two minutes of rest without maintaining the starting position, the former could be attributed to
the warm-up procedure adopted. For the present study, subjects were required to cycle for 5
minutes at a power output equivalent to between 80-90 watts. This protocol was accepted via
previous lab-based warm-ups for testing at the present study’s facilities, including heat chamber
exposure and isokinetic dynamometry tests. However, McCall et al (2015) implemented a 10-
minute warm up; seven minutes of pedalling at 90 watts followed by three minutes at 120 watts
for a supine isometric hamstring bridge test. It is worth mentioning that this study focussed on
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simulated match fatigue, as such a higher intensity warm-up was adopted. Although a fatiguing
effect will naturally occur during testing, the warm-up quality and quantity can play a significant
role in the severity of the fatiguing state experienced. Further testing could investigate the effect
of warm-up intensity on IPHF and to what extent the results lie within the limits of agreement in
order to determine the effectiveness of simulated match fatigue. Another potential avenue to
pursue is a study of test-retest versus a simulated fatigued state, in order to determine the impact
of an intense bout(s) of exercise would have on consistency.
Rate of force development (RoFD) was another variable collected throughout testing, with the
results published in the appendices of this report. Although considered an interesting data set to
examine, results showed a wide range of force development throughout subject trials. This could
stem from the informal countdown from three, with many subjects commencing their trial before
the end of the countdown, whilst others started after this. Although this relates to consistency in
coaching points and verbal instructions throughout testing, it is clear that rate of force development
was more consistent in the dominant leg than the non-dominant leg. Further research could
investigate torque ratios throughout testing and their effect on IPHF consistency.
.
Limitations
As only one practitioner was present for the trials, it is possible that technique may still have
been inconsistent despite attempts to standardise this. Employing a second practitioner to
monitor technique and manually limit hip extension and knee flexion would be recommended.
Although every effort was made to limit the movement of the couch, a sturdier but adjustable
platform specifically designed for IPHF testing may improve reliability further.
Conclusion
The present study has demonstrated that a standing hamstring bridge test is a reliable method for
determining IPHF in the general population. This method is more potentially more practical than
previously mentioned methods and as such represents a more suitable alternative for use within a
sports setting. Further research should focus on determining the sensitivity of the method with
regards to post-exercise fatigue, for example after a competitive match.
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References
Cohen, S. B., Towers, J. D., Zoga, A., Irrgang, J. J., Makda, J., Deluca, P. F., and Bradley, J. P.
(2011, 04). Hamstring Injuries in Professional Football Players: Magnetic Resonance Imaging
Correlation with Return to Play. Sports Health: A Multidisciplinary Approach, 3(5), 423-430.
Hopkins, W. G. (2015). Spreadsheets for analysis of validity and reliability. Sports Science, 19,
36-42.
McCall, A., Nedelec, M., Carling, C., Gall, F. L., Berthoin, S., and Dupont, G. (2015, 04).
Reliability and sensitivity of a simple isometric posterior lower limb muscle test in professional
football players. Journal of Sports Sciences, 33(12), 1298-1304.
Orchard, J., Best, T. M., and Verrall, G. M. (2005, 11). Return to Play Following Muscle Strains.
Clinical Journal of Sport Medicine, 15(6), 436-44.
Nosaka, K., Newton, M., and Sacco, P. (2002). Responses of human elbow flexor muscles to
electrically stimulated forced lengthening exercise. Acta Physiologica Scandinavica, 174, 137–
145.
Weir, J. P. (2005). Quantifying test-retest reliability using the intraclass coefficient and the
SEM. Journal of Strength & Conditioning Research, 19, 231–240.
Hopkins, W. G. (2002). A scale of magnitude for effect sizes. Retrieved from
http://www.sportsci.org/resource/stats/effectmag.html
Bland, J. M. and Altman, D. G. (1986). Statistical method for assessing agreement between two
methods of clinical measurement. The Lancet, 307-310.
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Appendices
Figure 3. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for RoFD at 100ms in the dominant leg.
Figure 4. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for RoFD at 150ms in the dominant leg.
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Figure 5. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for RoFD at 200ms in the dominant leg.
Figure 6. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for RoFD at 100ms in the non-dominant leg.
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Figure 7. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for RoFD at 150ms in the non-dominant leg.
Figure 8. Subject test-retest average plotted against the test-retest difference and the limits of
agreement for RoFD at 200ms in the non-dominant leg.