Muscle preactivation control: simulation of ankle joint adjustments at touchdown during running on uneven ground.

摘要: In locomotion, humans have to deal with irregularities in the ground. When they encounter uneven terrain changes vertical height, adjust geometry of their legs. Recent investigations shown that preactivation gastrocnemius muscle (GM) correlates ankle angle at touchdown, but it is as yet unclear why these adjustments were achieved by GM and not tibialis anterior (TA). To examine differences between TA regulation regarding (1) adjustment (2) joint stiffness, we used a three-segment musculoskeletal model two antagonistic muscles (GM, TA). During regulation, was adjusted from 121° 109° (dorsiflexion) 41% decrease activation. activation must be increased about 52%. addition, found stiffness most sensitive decreased 20% while adjusting angle. contrast, remains similar when using regulation. Thus, more adequate for joint, enabling sufficient stiffness.