Hussain Asif, Balasubramanian Sivakumar, Lamers Ilse, Guy Sarah, Feys Peter, Burdet Etienne
Department of Bioengineering, Imperial College of Science, Technology and Medicine, UK.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
J Rehabil Assist Technol Eng. 2016 Aug 26;3:2055668316663977. doi: 10.1177/2055668316663977. eCollection 2016 Jan-Dec.
Isometric force assessment can provide insights into strength and motor control in patients with neurological disabilities. This study investigated the connection between isometric strength and control in nine multiple sclerosis (MS) patients and four healthy subjects using a compact isometric setup. The participants carried out isometric assessment tasks in both upper extremities in six directions. Strength was measured through maximum voluntary force/torque (MVF/T), while control ability was measured by applying a constant force/torque of 25% of MVF/T. Isometric control was quantified using coefficient of variation, force directing ability, sample-entropy and spectral bandwidth. The MS patients were also assessed using two impairment measures (Motricity Index and hand-grip strength), and two activity measures (Action Research Arm Test and Nine Hole Peg Test). The results indicate that isometric strength and control (measured by spectral bandwidth) were correlated in most directions. Among the four control measures, spectral bandwidth - a measure introduced in this study - was found to be strongly related to the force/torque regularity as measured by sample-entropy. Isometric strength and spectral bandwidth for all directions were well correlated with the impairment measures, but their correlation with the activity scales was moderate and direction-dependent. Overall the results show potential for using the isometric setup and protocol for assessment in MS population.
等长肌力评估可以为神经功能障碍患者的力量和运动控制提供见解。本研究使用紧凑的等长设置，调查了9名多发性硬化症（MS）患者和4名健康受试者的等长肌力与控制之间的联系。参与者在六个方向上对双侧上肢进行了等长评估任务。通过最大自主力量/扭矩（MVF/T）测量力量，而控制能力则通过施加MVF/T的25%的恒定力量/扭矩来测量。使用变异系数、力导向能力、样本熵和频谱带宽对等长控制进行量化。还使用两种损伤测量方法（运动指数和握力）以及两种活动测量方法（动作研究臂测试和九孔插钉测试）对MS患者进行了评估。结果表明，等长肌力和控制（通过频谱带宽测量）在大多数方向上具有相关性。在四种控制测量方法中，频谱带宽——本研究中引入的一种测量方法——被发现与通过样本熵测量的力/扭矩规律性密切相关。所有方向的等长肌力和频谱带宽与损伤测量方法密切相关，但它们与活动量表的相关性中等且依赖于方向。总体而言，结果显示了使用等长设置和方案对MS人群进行评估的潜力。
