Kinesiology 4430F/G Lecture Notes - Lecture 9: Functional Electrical Stimulation, Motor Neuron
2 Oct 2016
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Using electrodes to stimulate a muscle for exercise purposes. These electrodes stimulate the nerves, which excites the axonal tissue (not the muscle itself) Useful for individuals who have limbs that do not work: Violates recruitment order preferential activation of ft mus. Exceeds safety factor (pattern of stimulation)) = fatigue. Motor neurons are not being recruited at anything less than 6-8 hz. Slow motoneurons are closer to the left hand side of the graph, and the faster motoneurons are closer to the right hand side of the graph. Upper range: 1-3 pulses at 100-200hz; sustained (2-4s) at mvc 25-60hz. This means that the slow twitch fibres have a longer refractory period in order to protect itself. Low range: biophysical properties of the cell related to refractory period: after- hyperpolarization ahp. If you change the innervation (attach a slow twitch nerve to a fast twitch fibre, and vice versa), the muscle fibres will eventually change to match the repolarization stage.
