Department of Physiotherapy, Hvidovre Hospital Kettegård Allé, 2950 Hvidovre, Denmark.
Clin Neurophysiol. 2012 Jul;123(7):1371-82. doi: 10.1016/j.clinph.2011.11.001. Epub 2011 Nov 25.
Spasticity is a common complication with neurological diseases and CNS lesions. Instrumented systems to evaluate spasticity often cannot provide an immediate result, thus limiting their clinical usefulness. In this study we investigated the accuracy and reliability of the portable Neurokinetics RA1 Ridgidity Analyzer to measure stiffness of the ankle joint in 46 controls, 14 spinal cord injured (SCI) and 23 multiple sclerosis (MS) participants.
Ankle stiffness measures were made twice by two raters, at speeds above and below the expected stretch reflex threshold. Ankle torque was measured with the portable device and a stationary torque motor. Inter- and intra-rater reliability was assessed with the intra-class correlation coefficient (ICC).
Stiffness measures with the portable and stationary devices were significantly correlated for controls and MS participants (p < 0.01). Intra-rater reliability for the portable device ranged from 0.60-0.89 (SCI) and 0.63-0.67 (control) and inter-rater reliability ranged from 0.70-0.73 (SCI) and 0.61-0.77 (control). Ankle stiffness measures in SCI and MS participants were significantly larger than in controls for both slow (p < 0.05) and fast movements (p < 0.01), with stiffness being larger for fast compared to slow movements in SCI and MS participants (p < 0.05), but not in controls (p = 0.5).
The portable device correlated well with measures obtained by a torque motor in both controls and MS participants, showed high intra- and inter-rater reliability for the SCI participants, and could easily distinguish between stiff and control ankle joints. However, the device, in its current form, may be less accurate during rapid movements when inertia contributes to stiffness and the shape of the air-filled pads did not provide a good interface with the foot.
This study demonstrates that a portable device can potentially be a useful diagnostic tool to obtain reliable information of stiffness for the ankle joint.
痉挛是神经疾病和中枢神经系统损伤的常见并发症。评估痉挛的仪器系统通常无法提供即时结果，因此限制了它们的临床实用性。在这项研究中，我们研究了便携式 Neurokinetics RA1 僵硬度分析仪测量 46 名对照者、14 名脊髓损伤 (SCI) 和 23 名多发性硬化 (MS) 参与者踝关节僵硬的准确性和可靠性。
由两名评分者以高于和低于预期牵张反射阈值的速度两次测量踝关节僵硬度。使用便携式设备和固定扭矩电机测量踝关节扭矩。使用组内相关系数 (ICC) 评估组内和组间可靠性。
便携式和固定式设备的僵硬度测量值在对照组和 MS 参与者中显著相关 (p < 0.01)。便携式设备的组内可靠性范围为 0.60-0.89 (SCI) 和 0.63-0.67 (对照)，组间可靠性范围为 0.70-0.73 (SCI) 和 0.61-0.77 (对照)。与对照组相比，SCI 和 MS 参与者的慢运动 (p < 0.05) 和快运动 (p < 0.01) 的踝关节僵硬度均显著增大，SCI 和 MS 参与者的快运动比慢运动的僵硬度更大 (p < 0.05)，但在对照组中则不然 (p = 0.5)。
该便携式设备与扭矩电机在对照组和 MS 参与者中的测量结果相关性良好，对 SCI 参与者具有较高的组内和组间可靠性，并且可以轻松区分僵硬和正常踝关节。然而，在当前形式下，当惯性对僵硬度有贡献且充气垫的形状不能与脚部很好地贴合时，该设备在快速运动中可能不太准确。
这项研究表明，便携式设备可能是一种有用的诊断工具，可用于可靠地获取踝关节僵硬度信息。
