FATIGUE-INDUCED EARLY ONSET OF ANTICIPATORY POSTURAL ADJUSTMENTS: HOW IS EARLY ONSET FUNCTIONAL?
To examine how fatigue-induced early onset of anticipatory postural adjustments (APAs) are functional, APAs of 30 participants were recorded before and after conditions of either rest (control group, n = 15) or a dead-lift task performed to exhaustion (fatigue group, n = 15). APAs were induced using a unilateral arm-raising maneuver, and were analyzed in the following muscles; lumbar paraspinal, thoracic paraspinal, and the hamstring group. Postural stability was assessed using a force plate. Fatigue had no effect on postural stability, and yet caused earlier APA onsets in 3 of the 6 postural muscles evaluated. Nevertheless, just 1 of the 3 muscles exhibiting early APA onset registered a greater APA EMG integral after the fatiguing task. The findings are consistent with the hypothesis that fatigue-induced early APA onset functions by affording the generation of a muscular impulse similar to that which would be generated in a non-fatigued state.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:postural control feedforward anticipatory adjustment
Date of Publication:01/01/2005