Postural reorganization following lower limb amputation. Possible motor and sensory determinants of recovery.

Postural control was assessed in persons with a unilateral lower limb amputation before and after their rehabilitation. The centre-of-pressure fluctuations during quiet upright standing on a dual-plate force platform were registered with and without visual information in order to identify relevant determinants of balance restoration. In addition, static (weight distribution) as well as dynamic (control activity) asymmetry characteristics were examined. Besides a small improvement in balance control with full visual information (fore-aft sway, p less than 0.06; lateral sway, p less than 0.05), there was a major decrease in visual dependency (fore-aft and lateral sway, p less than 0.05) indicating a somatosensory re-integration process. Postural asymmetry in comparison with matched control subjects was most apparent and only significant in dynamic terms and remained constant across rehabilitation. It is concluded that after a lower limb amputation a central reorganization of postural control takes place, in which sensory determinants of motor recovery may play a critical role.