Rapid unloading and a peak in power output of the ankle joint have been widely observed during push-off in human walking. Model-based studies hypothesize that this push-off causes redirection of the body center of mass just before touch-down of the leading leg. Other research suggests that work done by the ankle extensors provides kinetic energy for the initiation of swing. Also, muscle work is...

Electrical stimulation of the lateral gastrocnemius-soleus (LGS) nerve at group I afferent strength leads to adaptations in the amplitude and timing of extensor muscle activity during walking in the decerebrate cat. Such afferent feedback in the stance leg might result from a delay in stance onset of the opposite leg. Concomitant adaptations in hip abductor and adductor activity would then be e...

BACKGROUND The m. quadriceps femoris is the strongest muscle in the human body and plays an important role in sports, activities of daily living and independence. Two older studies showed increased electromyographic (EMG) activity of the quadriceps when the dorsal extensors of the foot were pre-activated. The aim was to physiologically replicate this finding by EMG and to verify it functionally...

The present study investigated the longitudinal growth of the vastus lateralis muscle using four eccentric exercise protocols with different mechanical stimuli by modifying the load magnitude, lengthening velocity and muscle length at which the load was applied. Thirty-one participants voluntarily participated in this study in two experimental and one control group. The first experimental group...

The ankle plantar flexors were previously shown to support the body in single-leg stance to ensure its forward progression [J. Biomech. 34 (2001) 1387]. The uni- (SOL) and biarticular (GAS) plantar flexors accelerated the trunk and leg forward, respectively, with each opposing the effect of the other. Around mid-stance their net effect on the trunk and the leg was negligible, consistent with th...

BACKGROUND The purpose of this study was to determine the effects of non-extensor muscles of the leg (i.e., muscles whose primary function is not leg extension) on the kinematics and kinetics of human maximal-effort countermovement jumping. Although it is difficult to address this type of question through experimental procedures, the methodology of computer simulation can be a powerful tool. ...

PURPOSE This study aimed to determine whether the tendency of women to exhibit higher knee extensor moments relative to hip extensor moments during the deceleration phase of landing can be explained by the relative strength of the knee and hip extensors. METHODS Forty recreationally active individuals participated in this study (20 men and 20 women). The maximum isometric strength of the knee...

purpose the purpose of this study was to evaluate the effect of an eight-week progressive resistance training and vibration program on strength and ambulatory function in multiple sclerosis (ms) patients. methods twenty-four female ms patients with the following demographics: age 27-45 years, and expanded disability status scale (edss) 2-4, participated in this study. the subjects were randomly...