KNPE 261 Lecture Notes - Lecture 8: Proprioception, Motor System, High Force
11 Mar 2018
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Low speed= high accuracy (more time to correct errors) Mvts (cid:272)a(cid:374) (cid:271)e (cid:395)ui(cid:272)k @ the (cid:272)ost of a(cid:272)(cid:272)u(cid:396)a(cid:272)y o(cid:396) a(cid:272)(cid:272)u(cid:396)ate at the (cid:272)ost of speed (cid:271)ut it"s diffi(cid:272)ult to do both. If trying to produce same force over and over, actual force is inconsistent: caused by noisy processes that convert cns impulses into activation of muscle mu. Motor variability is proportional to amount of force produced. Subject generates fixed level of force as force increases, more variable in maintaining constant force level. Muscle contractions @ 80% max voluntary contraction have higher variability: close to 100%, force actions amt of variability decreases again. Muscle contractions @ 20% max voluntary contraction have low variability. Peak force variability at 70-75% mvc and slightly until 100% mvc. Behaviour shows similar decrease in variability near max exertion. Decrease in variability for near max, very fast movement. Faster movement is more variable (more force required so more variability)
