Force steadiness of the hip abductors is associated with postural sway in both young and older adults

The potential influence of hip muscle activity on the control of postural sway is often overlooked. To explore this, we used the NIH toolbox test of standing balance as well as tests of force steadiness and maximal voluntary contraction torque for the ankle flexors and extensors and the hip abductor and adductors. We found that when either visual or reliable proprioceptive feedback was available, hip abductor force steadiness emerged as a significant predictor of the variance in postural sway area.