The aim of this study was to investigate the kinematical movements and electromyographic activities of the trunk and hip during trunk flexion and extension at different velocities. Thirteen male subjects performed trunk flexion and extension movements for 5 times at three different velocities of 1 s, 3 s, and 5 s in the standing position. Sagittal angular displacements of the lumbar spine, pelv...

CONTEXT The overhead throwing motion is complex, and restrictions in range of motion (ROM) at the hip may place additional demands on the shoulder that lead to injury. However, the relationship between hip and shoulder ROM in athletes with and without a history of shoulder injury is unknown. OBJECTIVE To (1) determine if differences exist in hip and shoulder ROM between professional baseball ...

BACKGROUND Hip strength is associated with numerous orthopaedic and neuromuscular injuries and/or pathologies and may be assessed with a variety of anatomic testing positions and techniques. Isokinetic dynamometers are generally too cumbersome and intricate for efficient use in mass screenings (for prognostic studies of risk for injury) as well as with special populations. The reliability of is...

INTRODUCTION The floor reaction ankle-foot orthosis is commonly prescribed in the attempt to decrease knee flexion during the stance phase in the cerebral palsy (CP) gait. Reported information about this type of orthosis is insufficient. PURPOSE The purpose of this study was to determine the effect of clinically prescribed floor reaction ankle-foot orthosis on kinematic parameters of the hip,...

Farm youth often carry loads that are proportionally large and/or heavy, and field measurements have determined that these tasks are equivalent to industrial jobs with high injury risks. The purpose of this study was to determine the effects of age, load amount, and load symmetry on lower extremity joint moments during carrying tasks. Three age groups (8-10 years, 12-14 years, adults), three lo...

BACKGROUND The anterior approach to the hip gained popularity for total hip arthroplasty in recent years. Distal extension of the anterior approach, sometimes needed intraoperatively, potentially endangers neurovascular structures to the quadriceps. The aim of this study was to determine the anatomical structures placed at risk by distal extension of the anterior approach to the hip. METHODS ...

The biomechanical characteristics of stiff knee gait following neurological injury include decreased knee flexion velocity at toe-off, which may be due to exaggerated quadriceps activity. The neuromuscular mechanism underlying this abnormal activity is unclear, although hyperexcitable heteronymous reflexes may be a source of impaired coordination. The present study examines the contribution of ...

There are no direct recordings of obturator internus muscle activity in humans because of difficult access for electromyography (EMG) electrodes. Functions attributed to this muscle are based on speculation and include hip external rotation/abduction, and a role in stabilization as an "adjustable ligament" of the hip. Here we present (1) a technique to insert intramuscular EMG electrodes into o...

Injuries to the sciatic nerve are an occasional complication of surgery to the hip and acetabulum, and traction is frequently the causative mechanism. In vitro and animal experiments have shown that increased tensile strain on peripheral nerves, when applied for prolonged periods, impairs nerve function. We have used video-extensometry to measure strain on the human sciatic nerve during total h...