The role of cutaneous receptors in the foot.

Cutaneous receptors in the foot sole appear to contribute to the control of human stance and locomotion. Two approaches were undertaken to establish the characteristics of the receptors in the sole. Psychophysical vibrotactile thresholds (range 25-400 Hz) were determined across the unloaded sole in young and elderly subjects. Thresholds were lower in the ball and arch of the sole, than in the heel and toe regions. Elderly subjects demonstrated significantly elevated thresholds for high-frequency vibration. Secondly, microneurographic recordings were made from skin afferents of the unloaded sole in young subjects. Results indicated that while similar types of cutaneous receptors exist in the sole of the foot and hand, there appear to be differences in receptor density and distribution. Our results demonstrate that cutaneous afferent inputs from the foot sole provide useful information for the control of posture and locomotion.