Effect of light finger touch on postural sway after lower-limb muscular fatigue.

OBJECTIVE

To investigate whether a light finger touch can compensate for the increased postural sway induced by lower-limb muscular fatigue.

DESIGN

Before-after trials.

SETTING

General community.

PARTICIPANTS

Nine healthy university students (mean age, 23.8+/-2.6y; mean body weight, 72.7+/-6.9 kg; mean height, 177.2+/-7.5 cm).

INTERVENTIONS: Participants stood with their feet together and eyes closed. They were asked to sway as little as possible in 4 conditions: no fatigue/no touch, no fatigue/touch, fatigue/no touch, and fatigue/touch. Calf muscle fatigue was induced by having participants stand on their toes until exhaustion. Touch conditions involved a gentle light touch with the right index finger on a nearby surface at waist height.

MAIN OUTCOME MEASURES: Center of pressure displacements were recorded by using a force platform.

RESULTS

Light finger touch resulted in decreased postural sway in the no-fatigue and fatigue conditions. Interestingly, this stabilizing effect was more accentuated in the fatigue condition.

CONCLUSIONS

Results suggest that the contribution of the haptic cues from the finger for regulating postural sway increases after muscular fatigue. These findings could have implications in clinical and rehabilitative areas.