FEEDBACK-BASED TRAINING OF GRIP FORCE CONTROL IN PATIENTS WITH BRAIN-DAMAGE

Objective: Feedback-based training of grip force control in patients w ith various brain lesions was evaluated. Design: Patients were instruc ted to hold a force transducer in a precision grip and to track with t heir grip force a moving target, which was presented together with the feedback signal on a monitor. Training performance was evaluated duri ng a maximum of 10 sessions. Before and after the training, performanc e in two transfer tasks, which differed in target characteristics from the training task, was examined. Patients: Ten patients with impaired grip force control, after brain lesions of different origin, were sel ected on the basis of a clinical examination of hand function. Main Ou tcome Measures: Tracking accuracy in training tasks and transfer tasks was evaluated by calculating the conventional root-mean-square error. Results: Nine out of the 10 patients reduced their tracking error con siderably during a maximum of 10 subsequent sessions (t test, p < 0.05 ), and most of them reached normal or near-normal performance. In addi tion, they improved in both transfer tasks (t test, p < 0.05). Detaile d analysis showed that impaired initial performance and improvement wa s not uniform among patients and could be attributed to individual asp ects of force control. Conclusions: In view of these results, a feedba ck-based training of grip force may be a useful enrichment of motor th erapy. (C) 1995 by the American Congress of Rehabilitation Medicine an d the American Academy of Physical Medicine and Rehabilitation