Dual-task assessment of reorganization of postural control in persons with lower limb amputation

Postural control in persons with lower limb amputation was studied using a cognitive approach to motor learning. The aim of this study was to show that an important characteristic of the central reorganization process after a lower limb amputation is the gradually decreasing need of attentional resources to perform a motor task. A dual-task procedure was developed to estimate the level of automaticity of a quiet, upright standing task. The effect of a concurrent attention-demanding task (Stroop task) on the efficiency of balance control was determined using force-platform measurements at the start and the end of the rehabilitation process. In contrast with a control group, the amputation group showed interference effects on body sway caused by the concurrent task both at the start (p less than .05) and, less severe, at the end of rehabilitation (p less than .05). Improvement of balance control was significant only for the dual-task condition (p less than .05). The results corroborated the hypothesis that dual tasks give information about the restoration of automaticity of postural control as an essential characteristic of the central reorganization process in persons with lower limb amputation. The role of dual-task procedures as a useful approach to skill assessment is discussed.