Mechanical arm trainer for the treatment of the severely affected arm after a stroke: a single-blinded randomized trial in two centers

Abstract

Objective: To test whether training with a new mechanical arm trainer leads to better outcomes than electrical stimulation of the paretic wrist extensors in subacute stroke patients with severe upper limb paresis. Electrical stimulation is a standard and reimbursable form of therapy in Germany.

Design: Randomized controlled trial of 54 inpatients enrolled 4-8 wks from stroke onset, mean upper-extremity subsection of Fugl-Meyer assessment (0-66) at admission less than 18. In addition to standard care, all patients practiced 20-30 mins arm trainer or electrical stimulation every workday for 6 wks, totaling 30 sessions. Primary outcome was the Fugl-Meyer assessment, secondary outcomes were the Box and Block test, the Medical Research Council and the modified Ashworth scale, blindly assessed at enrollment, after 6 wks, and at 3-mo follow-up.

Results: Both groups were homogeneous at study onset. Shoulder pain occurred in two arm trainer patients. The primary Fugl-Meyer assessment outcome improved for both groups over time (P < 0.001), but this improvement did not differ between groups. The initial (terminal) mean Fugl-Meyer assessment scores were 8.8 +/- 4.8 (19.2 +/- 14.5) for the arm trainer and 8.6 +/- 3.5 (13.6 +/- 7.9) for the electrical stimulation group. No patient could transport a block initially, but at completion significantly more arm trainer patients were able to transport at least three blocks (five vs. zero, P = 0.023). No significant differences were observed between the groups on the secondary Box and Block outcome at follow-up (eight vs. four patients). All Box and Block responders had an initial Fugl-Meyer assessment > or =10.

Conclusions: Arm trainer training did not lead to a superior primary outcome over electrical stimulation training. However, "good performers" on the secondary outcome seemed to benefit more from the arm trainer training.