Efficacy of three interventions at mitigating the adverse effects of muscle fatigue on postural control.
Lin-D; Nussbaum-MA; Madigan-ML
Ergonomics 2012 Jan; 55(1):103-113
This study evaluated the efficacy of three interventions at reducing the adverse effects of muscle fatigue on postural control. The first provided rest breaks according to perceived decrements in postural stability, while the other two involved auditory stimulations (static pure tone and moving conversation). Sixteen participants performed repetitive box handling (lifting + lowering) over 1.5 h to induce muscle fatigue mainly in the lumbar extensors. Trials of quiet upright stance were completed at 10-min intervals, during which the interventions (or a control condition) were applied. Postural control was assessed using perceived stability (PS) and several measures derived from centre-of-pressure (COP) time series. Allowance of rest breaks did not significantly affect any of the objective measures, though a trend indicated an offset to fatigue-induced decreases in PS. Both the static pure tone and moving conversation led to significant changes in the dependent measures indicating a mitigation of fatigue-induced postural instability. PRACTITIONER SUMMARY: We examined the effects of three control strategies on postural control in the presence of muscle fatigue induced by a simulated occupational task. The findings can facilitate the development of future strategies or practical interventions to reduce falling risk and prevent falls.
Biomechanics; Muscle-physiology; Muscles; Posture; Fatigue; Muscle-function; Humans; Manual-lifting; Manual-materials-handling; Repetitive-work; Acoustics; Stimulants; Rest-periods; Work-intervals; Control-methods; Task-performance; Simulation-methods; Measurement-equipment; Injury-prevention; Accident-potential; Accident-prevention; Voice-communication;
Author Keywords: postural control; muscle fatigue; intervention; auditory stimulation; falls; quiet stance
Maury A. Nussbaum, Department of Industrial and Systems Engineering, Virginia Tech, Blacksburg, VA 24061, USA
Virginia Polytechnic Institute and State University