Biomechanical Evaluation of Dynamic Splint Based on Pulley Rotation Design for Management of Hand Spasticity

Abstract

A dynamic splint is superior to traditional static splint, offering more benefits such as reduced spasticity, allowing comfortable stretch, repositioning fingers in extension positions, and increasing hand performance. This paper suggested the development of a dynamic splint based on a pulley rotation with a locking system as a home rehabilitation device to reduce hand spasticity in stroke patients. Moreover, this study consisted of two main activities: simulation using finite element analysis and clinical experimental trials. Eight stroke patients participated in 4 weeks of intervention using the proposed dynamic splint for a combined total of least 3 hours per day at home. Outcome measures included Fugl-Meyer Assessment (FMA) and Modified Modified Ashworth Scale (MMAS) at baseline, 2 weeks, and 4 weeks. After 4 weeks of wearing, participants were also asked to fill out a satisfaction questionnaire. The results showed that wearing this proposed dynamic splint over 4 weeks, the hand function of participants increased significantly(p < 0.05), and the spasticity of the hand muscles decreased significantly(p < 0.05). With an overall rating of 8 out of 10 points, stroke participants had a high level of satisfaction with this home-use dynamic splint. The findings indicated that stroke patients who used this proposed splint showed substantial changes in hand function and reduced hand spasticity.

Effectiveness of a New 3D-Printed Dynamic Hand–Wrist Splint on Hand Motor Function and Spasticity in Chronic Stroke Patients

“…Several previous studies have described a variety of dynamic splints that effectively improved motor function and relieved spasticity in stroke patients [ 16 , 17 , 32 , 42 ]. In comparison to a static splint, a dynamic splint consists of a static base that forms the foundation of the splint, and an outrigger, the mobile part consisting of levers, springs, or pulleys.…”

“…In addition, the fingers could be stretched in extension with the wrist, extended by a simple locking mechanism for a prolonged time. Our previous study had shown that stretching three fingers (thumb, index, and middle fingers) reduced the finger flexors’ spasticity, and the splint was easy to self-use at home [ 32 ]. Therefore, we used a 3D-printed dynamic splint with a novel three-finger design in the current study.…”

“…To overcome the problems, we developed a dynamic splint based on a pulley rotation design. The results demonstrated the beneficial effects of this dynamic splint in eight chronic stroke patients, during a 4-week intervention [ 32 ]. However, the dynamic splint was found to have some limitations in some chronic stroke survivors.…”

“…This dynamic splint was intended to be effective in reducing spasticity, easy to fabricate, convenient to operate, and comfortable to wear. Moreover, based on our previous research, we observed that chronic stroke patients who wore the dynamic splints for longer than scheduled showed tremendous improvement, as compared to the group who had a schedule of wearing the splints 3 h a day [ 32 ]. A previous study had also indicated that the use of a dynamic splint for at least 6 h per day significantly reduced wrist contractures, causing less pain [ 17 ].…”

Quantitative Elbow Spasticity Measurement Based on Muscle Activation Estimation Using Maximal Voluntary Contraction

“…The limitation of joint range of motion and exaggeration of stretch reflexes increase with the severity of spasticity [1], which impacts the life quality for stroke patients and brings challenges to rehabilitation therapies. Previous studies demonstrated that comprehensive evaluation of spasticity improved the efficiency of rehabilitation [2], [3]. Conventionally, the most commonly used spasticity measurement methods in practice are clinical scales, e.g., Modified Ashworth Scale (MAS) [4], [5], and Australian Spasticity Assessment Scale (ASAS) [6].…”