Muscle And Synthesis Essay

Background of physiological context
Previously, Capaday and Stein (1986) had conducted a study which aimed at investigating the amplitude modulation of the soleus H-reflex during the step cycle of human locomotion. The walking and stance phases of locomotion were investigated. This study showed that the H-reflex during walking was modulated greater than in the stance phase. The outcome of this study concluded that there were other central neural mechanisms which modulated the amplitude of the H-reflex and it was not just the consequence of α-motor neuron excitation levels. In the current paper, Capaday and Stein investigated the modulation of the H-reflex and whether it is similar in running as it is in walking in the same subject. This investigation expected the modulation of the H-reflex to be different in the two separate locomotion types. It was said running would elicit a greater H-reflex amplitude due to the increase in impact force between the ankle and the ground. This greater H-reflex amplitude would have been required to further stiffen the ankle joint before impact. It was noted that if differences between H-reflex and e.m.g were observed between the two locomotion types this study would provide further evidence that modulation of the

Silver electrodes were used to record the e.m.g of the soleus muscle and tibialis anterior, and stimulate the tibial nerve below the popliteal fossa. The use of the electrodes to stimulate the tibial whilst walking and running was found to be problematic, this is because the nerves distance from the electrode was continually changing, therefore altering the stimulus strength. This was eradicated by repetition at different intensities and use of the M-wave, allowing comparison of similar stimulus intensities through the locomotion