Foot anatomy specialization for postural sensation and control
- 29 February 2012
- journal article
- research article
- Published by American Physiological Society in Journal of Neurophysiology
- Vol. 107 (5), 1513-1521
- https://doi.org/10.1152/jn.00256.2011
Abstract
Wright WG, Ivanenko YP, Gurfinkel VS. Foot anatomy specialization for postural sensation and control. J Neurophysiol 107: 1513-1521, 2012. First published December 7, 2011; doi:10.1152/jn.00256.2011.-Anthropological and biomechanical research suggests that the human foot evolved a unique design for propulsion and support. In theory, the arch and toes must play an important role, however, many postural studies tend to focus on the simple hinge action of the ankle joint. To investigate further the role of foot anatomy and sensorimotor control of posture, we quantified the deformation of the foot arch and studied the effects of local perturbations applied to the toes (TOE) or 1st/2nd metatarsals (MT) while standing. In sitting position, loading and lifting a 10-kg weight on the knee respectively lowered and raised the foot arch between 1 and 1.5 mm. Less than 50% of this change could be accounted for by plantar surface skin compression. During quiet standing, the foot arch probe and shin sway revealed a significant correlation, which shows that as the tibia tilts forward, the foot arch flattens and vice versa. During TOE and MT perturbations (a 2- to 6-mm upward shift of an appropriate part of the foot at 2.5 mm/s), electromyogram (EMG) measures of the tibialis anterior and gastrocnemius revealed notable changes, and the root-mean-square (RMS) variability of shin sway increased significantly, these increments being greater in the MT condition. The slow return of RMS to baseline level (> 30 s) suggested that a very small perturbation changes the surface reference frame, which then takes time to reestablish. These findings show that rather than serving as a rigid base of support, the foot is compliant, in an active state, and sensitive to minute deformations. In conclusion, the architecture and physiology of the foot appear to contribute to the task of bipedal postural control with great sensitivity.Keywords
This publication has 58 references indexed in Scilit:
- Tonic postural lean after-effects influenced by support surface stability and dynamicsHuman Movement Science, 2011
- The proprioceptive and agonist roles of gastrocnemius, soleus and tibialis anterior muscles in maintaining human upright postureThe Journal of Physiology, 2009
- Identification of the Plant for Upright Stance in Humans: Multiple Movement Patterns From a Single Neural StrategyJournal of Neurophysiology, 2008
- Arch height change during sit‐to‐stand: an alternative for the navicular drop testJournal of Foot and Ankle Research, 2008
- The passive, human calf muscles in relation to standing: the non‐linear decrease from short range to long range stiffnessThe Journal of Physiology, 2007
- Effects of experimentally induced plantar insensitivity on forces and pressures under the foot during normal walkingGait & Posture, 2004
- Endurance running and the evolution of HomoNature, 2004
- Evaluation of early walking patterns from plantar pressure distribution measurements. First year results of 42 childrenGait & Posture, 2004
- Coding of modified body schema during tool use by macaque postcentral neuronesNeuroReport, 1996
- Task-dependent effects evoked by foot muscle afferents on leg muscle activity in humansElectroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, 1996