Comparative effects of dynamic and static stretching on spasticity reduction in stroke patients using a robotic hand-wrist stretching device

Background: Spasticity is a common consequence of upper motor neuron syndrome, affecting approximately 42.6% of stroke patients and impairing quality of life. Although stretching is widely used, the optimal type and parameters remain unclear. Objective: This study investigates the immediate effects of dynamic and static stretching on spasticity reduction and motor function improvement in stroke patients using a robotic hand-wrist stretching device (RHWSD). Methods: This study was a randomized crossover trial with double-blind design. Thirty-one stroke patients with wrist flexor spasticity were randomly assigned to three RHWSD stretching protocols: 30° dynamic stretching (30° DS), 60° static stretching (60° SS), and 60° dynamic stretching (60° DS). Each protocol involved a 3-minute session with 20-minute rest intervals. Wrist flexor spasticity was assessed with the Modified Ashworth Scale (MAS). Active range of motion (AROM) and passive range of motion (PROM) of wrist extension and finger metacarpophalangeal (MP) extension, were measured at baseline and after each session. Results: Significant reductions in MAS scores were observed with both dynamic stretching protocols (30° DS: 2.45 ± 0.72; 60° DS: 2.48 ± 0.63) compared to static stretching (60° SS: 2.94 ± 0.51; p <.000). Both dynamic protocols yielded significantly greater gains in AROM and PROM for wrist and finger MP extension than static stretching (all p <.001). Conclusions: Dynamic stretching is more effective at reducing spasticity in stroke patients. A stretching angle of 80% of the normal range (60°) is sufficient to achieve significant improvements in ROM. The RHWSD was effective in providing consistent stretching.