Goudriaan Marije, Nieuwenhuys Angela, Schless Simon-Henri, Goemans Nathalie, Molenaers Guy, Desloovere Kaat
KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Neuromotor Rehabilitation Research Group, Leuven, Belgium.
KU Leuven-University of Leuven, Department of Development and Regeneration, Organ Systems, Leuven, Belgium.
PLoS One. 2018 Jan 11;13(1):e0191097. doi: 10.1371/journal.pone.0191097. eCollection 2018.
The main goal of this validation study was to evaluate whether lower limb muscle weakness and plantar flexor rate of force development (RFD) related to altered gait parameters in children with cerebral palsy (CP), when weakness was assessed with maximal voluntary isometric contractions (MVICs) in a gait related test position. As a subgoal, we analyzed intra- and intertester reliability of this new strength measurement method.
Part 1 -Intra- and intertester reliability were determined with the intra-class correlation coefficient (ICC2,1) in 10 typical developing (TD) children (age: 5-15). We collected MVICs in four lower limb muscle groups to define maximum joint torques, as well as plantar flexor RFD. Part 2 -Validity of the strength assessment was explored by analyzing the relations of lower limb joint torques and RFD to a series of kinematic- and kinetic gait features, the GDI (gait deviation index), and the GDI-kinetic in 23 children with CP (GMFCS I-II; age: 5-15) and 23 TD children (age: 5-15) with Spearman's rank correlation coefficients.
Part 1 -The best reliability was found for the torque data (Nm), with the highest ICC2,1 (0.951) for knee extension strength (inter) and the lowest (0.693) for dorsiflexion strength (intra). For plantar flexor RFD, the most reliable window size was 300 milliseconds (ICC2,1: 0.828 (inter) and 0.692 (intra)). Part 2 -The children with CP were significantly weaker than the TD children (p <0.001). Weakness of the dorsiflexors and plantar flexors associated with delayed and decreased knee flexion angle during swing, respectively. No other significant correlations were found.
While our new strength assessment was reliable, intra-joint correlations between weakness, RFD, and gait deviations were low. However, we found inter-joint associations, reflected by a strong association between plantar- and dorsiflexor weakness, and decreased and delayed knee flexion angle during swing.
本验证研究的主要目标是评估当在与步态相关的测试位置通过最大自主等长收缩（MVIC）评估下肢肌肉无力时，脑瘫（CP）患儿的下肢肌肉无力和跖屈肌力量发展速率（RFD）是否与步态参数改变有关。作为一个次要目标，我们分析了这种新的力量测量方法在测试者内部和测试者之间的可靠性。
第1部分 - 在10名发育正常（TD）儿童（年龄：5 - 15岁）中，使用组内相关系数（ICC2,1）确定测试者内部和测试者之间的可靠性。我们收集了四个下肢肌肉群的MVIC，以确定最大关节扭矩以及跖屈肌RFD。第2部分 - 通过分析23名CP患儿（GMFCS I - II；年龄：5 - 15岁）和23名TD儿童（年龄：5 - 15岁）的下肢关节扭矩和RFD与一系列运动学和动力学步态特征、步态偏差指数（GDI）以及GDI - 动力学之间的关系，采用Spearman等级相关系数来探索力量评估的有效性。
第1部分 - 扭矩数据（Nm）的可靠性最佳，膝关节伸展力量（测试者间）的ICC2,1最高（0.951），背屈力量（测试者内）的ICC2,1最低（0.693）。对于跖屈肌RFD，最可靠的窗口大小为300毫秒（ICC2,1：测试者间为0.828，测试者内为0.692）。第2部分 - CP患儿明显比TD儿童虚弱（p <0.001）。背屈肌和跖屈肌的无力分别与摆动期膝关节屈曲角度延迟和减小有关。未发现其他显著相关性。
虽然我们新的力量评估是可靠的，但无力、RFD和步态偏差之间的关节内相关性较低。然而，我们发现了关节间的关联，表现为跖屈肌和背屈肌无力之间的强烈关联，以及摆动期膝关节屈曲角度减小和延迟。
