Characteristics of F-wave in different stretched positions of the affected arm in patients with cerebrovascular diseases

To investigate the effect of continued stretching of affected arms in patients with cerebrovascular disease (CVD), F-wave was tested from the abductor pollicis brevis (APB) during relaxation (trial 1) and 3 different continued stretches: stretched position with shoulder abduction (trial 2), stretched position with shoulder abduction and elbow extension (trial 3), and stretched position with shoulder abduction, elbow extension and wrist extension (trial 4) of the affected arm for 1 min. in 20 hemiparesis patients with moderate hypertonus (modified Ashworth scale of 2 or 3) caused by CVD (mean age of 49.5 years). Persistence and amplitude ratio of F/M in trial 2 were the same as those in trial 1. Persistence and amplitude ratio of F/M in trials 3 and 4 were significantly lower than those in trial 1. It was suggested that excitability of spinal neural function of the distal part, the APB, of the affected arm was reduced during continued stretching of the proximal part, shoulder and elbow joints, or all of the shoulder, elbow and wrist joints in hemiparesis patients with moderate hypertonus caused by CVD.