The hypothesis that the pattern of muscle activation during a static voluntary effort exerted in different directions is oriented in the direction of the muscle's mechanical action was evaluated. The electromyographical (EMG) activation patterns of five hip muscles (gluteus medius, rectus femoris, tensor fasciae latae, gracilis and semitendinosus) and one knee muscle (vastus lateralis) were cha...

Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extensi...

Although the movement of the leg during swing phase is often compared to the unforced motion of a compound pendulum, the muscles of the leg are active during swing and presumably influence its motion. To examine the roles of muscles in determining swing phase knee flexion, we developed a muscle-actuated forward dynamic simulation of the swing phase of normal gait. Joint angles and angular veloc...

BACKGROUND Quadriceps function is an important measure in patients recovering postoperatively. Traditionally, strength measures that require high levels of resistance are contraindicated during the early postoperative phase. Thus it may be helpful to evaluate the utilization of other tools, such as ultrasound imaging, that allow for assessment during a position of low resistance. HYPOTHESIS T...

[Purpose] To compare the appearance time of the ventilatory threshold point and the electromyographic threshold in the activity of the vastus lateralis, rectus femoris, biceps femoris long head and gastrocnemius lateral head muscles during ramp cycling exercise in elderly males. [Subjects and Methods] Eleven community dwelling elderly males participated in this study. Subjects performed exercis...

BACKGROUND AND PURPOSE Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent-knee sit-up. The purpose of this study was to test the effectiveness o...

Imaging techniques allow in vivo measurement of parameters studied in vitro or ex vivo and thus greater reliability regarding muscle mechanics in real situations. Some muscle architecture parameters are directly related to force production, mainly the volume. It can be estimated by the sum of segmental volumes (product of the sum of crosssectional areas and the distance between them) of sequent...