Kinesiology 4430F/G Lecture Notes - Lecture 10: Caffeine, Motor Cortex, Myosin

• School: Western University
• Department: Kinesiology
• Course: Kinesiology 4430F/G
• Professor: Charles Rice

Document Summary

Different fibres were measured during different forces and durations of contractions. At low force, someone is holding the contraction for 20-30 seconds. At high force, someone is holding a high force contraction for awhile, but during the high force contraction they can only hold it for a few seconds. Recruitment may be more prevalent at lower forces and firing rates more for higher forces, but they co-exist. Different muscles = different tasks, = different combinations of rate coding/recruitment. Steady state force is maintained without additional recruitment, but decline in firing rates. The system wants to conserve as much as possible to get the job done. A fixed, maximal stimulus will cause a single twitch in the muscle. When placed at a higher frequency, a higher force will be produced. After receding, we give the same muscle the same fixed, maximal stimulus as before (no frequency) This causes a greater/larger twitch than the first twitch, which is called the post-