Segmental muscle vibration improves reaching movement in patients with chronic stroke. A randomized controlled trial

BACKGROUND: Segmental muscle vibration (SMV) has been used to improve gait and to reduce spasticity in stroke patients. No data exist about the possibility to improve upper limb motor function by using SMV. METHODS: Forty-four patients with hemiparesis following chronic stroke were randomized to an experimental (n = 24) and a control group (n = 20). Patients in the experimental group received two weeks of general physical therapy and SMV over the biceps brachii and flexor carpi ulnaris muscles of the paretic side, while those in the control group received two weeks of general physical therapy. Kinematic analysis of reaching movement was performed at baseline and two weeks after treatment ended. RESULTS: Normalized jerk, indicating the smoothness of movement, significantly improved in the experimental group, with significant difference emerging between groups at the post-treatment evaluation. Patients in the experimental group also displayed a significant improvement for mean linear velocity, mean angular velocity at shoulder, distance to target at the end of movement and movement duration. No differences emerged between baseline and post-treatment evaluations in the control group. CONCLUSIONS: when added to general physical therapy, SMV is effective in improving, in a short-term period, upper limb motor performances of reaching movement in chronic stroke patients.