CONTEXT Female soccer athletes are at greater risk of anterior cruciate ligament (ACL) injury than males. Sex differences in muscle activation may contribute to the increased incidence of ACL injuries in female soccer athletes. OBJECTIVE To examine sex differences in lower extremity muscle activation between male and female soccer athletes at the National Collegiate Athletic Association Divis...

CONTEXT Fatigue appears to influence musculoskeletal injury rates during athletic activities, but whether males and females respond differently to fatigue is unknown. OBJECTIVE To determine the influence of fatigue on vertical leg stiffness (K (VERT)) and muscle activation and joint movement strategies and whether healthy males and females respond similarly to fatigue. DESIGN Repeated-measu...

We discovered that the contemporary procedure for assessing voluntary activation of knee extensor muscles with transcranial magnetic stimulation (TMS) is invalid. TMS activates too few agonist quadriceps motoneurons and many antagonist hamstrings to estimate resting twitch accurately. A modified procedure, in which TMS-evoked superimposed twitches are considered together from femoral nerve stim...

PURPOSE To assess the immediate effect of hamstring and abdominal activation on pain levels as measured by the Numeric Pain Scale (NPS) and hip range of motion as measured by Ober's Test in people with lumbopelvic pain. METHODS Thirteen participants with lumbopelvic pain and positive Ober's Tests completed an exercise developed by the Postural Restoration Institute™ to recruit hamstrings and ...

Children with cerebral palsy often walk with reduced knee extension in terminal swing, which can be associated with short length or slow lengthening velocity of hamstrings muscles during gait. This study investigated the role of two factors that may contribute to such short and slow hamstrings: walking speed and spasticity. 17 children with spastic cerebral palsy and 11 matched typically develo...

BACKGROUND Anterior cruciate ligament (ACL) injuries often occur during landing, with female athletes at higher injury risk than male athletes. Interestingly, female dancers have lower ACL injury rates than do female athletes in general. HYPOTHESIS Female dancers will have earlier and greater lower extremity muscle activity and higher sagittal knee joint and leg stiffness than will female bas...

In healthy subjects, electromyography (EMG) reveals that well-coordinated walking can be produced by exciting four co-activation modules: Module 1 (hip and knee extensors) in early stance, Module 2 (ankle plantarflexors) in late stance, Module 3 (tibialis anterior and rectus femoris) during swing, and Module 4 (hamstrings) in late swing and early stance [1]. These modules, comprised of timing a...

Aims: To investigate the effect of hamstrings’ cooling and short-duration Cryostretching on sit and reach flexibility test (SR) performance. Study Design: Crossover Randomized Clinical Trial. Place and Duration of the Study: Department of Physical Therapy, Technological Educational Institute (TEI) of Western Greece, Aigio Achaias, Greece, 3 months. Methodology: Eighteen (18) healthy male (age: ...