Poster 199: Support specific modulation of grip force in persons with hemiparesis.

Abstract

Objective: To characterize changes in the grip force with provision of a support while performing the tasks of lifting and transporting a cup. Design: Seated subjects lifted and transported a cup that was instrumented with 2 strain gauges with no support, while the arm was positioned on a freely moving skateboard, and with a light touch of the index finger of the contralateral arm. Setting: Free-standing acute inpatient rehabilitation hospital. Participants: 6 persons with unilateral hemiparesis and 6 healthy control subjects. Interventions: Not applicable. Main Outcome Measures: Normalized grip force and temporal coupling between the grip force application and lift-off of the cup. Results: In the no-support conditions, persons with hemiparesis applied significantly larger grip force with the affected arm compared with the control subjects (57.5%±18.49% vs 38.78%±21.12%, P<.05). In the light-touch conditions, both groups needed smaller grip force to lift and transport the same cup (persons with hemiparesis, 51.05%±21.36%; healthy subjects, 33.52%±22.65%). Persons with hemiparesis demonstrated statistically significant prolongation of timing between the grip force application and the lift-off of the object as compared with the control subjects ( P<.05). Conclusions: Providing supports to the affected extremity while lifting and manipulating an object could be a useful strategy in reducing grip force and improving functional performance in persons with impaired upper-extremities force control.