Huang Meizhen, Tang Chak-Yin, Pang Marco Y C
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong.
Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong.
J Biomech. 2018 May 17;73:80-91. doi: 10.1016/j.jbiomech.2018.03.022. Epub 2018 Mar 17.
This study examined (1) the influence of whole body vibration (WBV) frequency (20 Hz, 30 Hz, 40 Hz), amplitude (low: 0.8 mm and high: 1.5 mm) and body postures (high-squat, deep-squat, tip-toe standing) on WBV transmissibility and signal purity, and (2) the relationship between stroke motor impairment and WBV transmissibility/signal purity. Thirty-four participants with chronic stroke were tested under 18 different conditions with unique combinations of WBV frequency, amplitude, and body posture. Lower limb motor function and muscle spasticity were assessed using the Fugl-Meyer Assessment and Modified Ashworth Scale respectively. Nine tri-axial accelerometers were used to measure acceleration at the WBV platform, and the head, third lumbar vertebra, and bilateral hips, knees, and ankles. The results indicated that WBV amplitude, frequency, body postures and their interactions significantly influenced the vibration transmissibility and signal purity among people with chronic stroke. In all anatomical landmarks except the ankle, the transmissibility decreased with increased frequency, increased amplitude or increased knee flexion angle. The transmissibility was similar between the paretic and non-paretic side, except at the ankle during tip-toe standing. Less severe lower limb motor impairment was associated with greater transmissibility at the paretic ankle, knee and hip in certain WBV conditions. Leg muscle spasticity was not significantly related to WBV transmissibility. In clinical practice, WBV amplitude, frequency, body postures need to be considered regarding the therapeutic purpose. Good contact between the feet and vibration platform and symmetrical body-weight distribution pattern should be ensured.
（1）全身振动（WBV）频率（20赫兹、30赫兹、40赫兹）、振幅（低：0.8毫米和高：1.5毫米）以及身体姿势（高蹲、深蹲、踮脚尖站立）对WBV传递率和信号纯度的影响；（2）中风运动障碍与WBV传递率/信号纯度之间的关系。34名慢性中风患者在18种不同条件下接受测试，这些条件为WBV频率、振幅和身体姿势的独特组合。分别使用Fugl-Meyer评估法和改良Ashworth量表评估下肢运动功能和肌肉痉挛程度。使用九个三轴加速度计测量WBV平台、头部、第三腰椎以及双侧髋部、膝盖和脚踝处的加速度。结果表明，WBV振幅、频率、身体姿势及其相互作用对慢性中风患者的振动传递率和信号纯度有显著影响。在除脚踝外的所有解剖标志点，传递率随频率增加、振幅增加或膝关节屈曲角度增加而降低。除了踮脚尖站立时脚踝处，患侧和非患侧的传递率相似。在某些WBV条件下，下肢运动障碍较轻与患侧脚踝、膝盖和髋部更高的传递率相关。腿部肌肉痉挛与WBV传递率无显著相关性。在临床实践中，应根据治疗目的考虑WBV振幅、频率和身体姿势。应确保双脚与振动平台之间良好接触以及对称的体重分布模式。
