Department of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
Department of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece.
J Back Musculoskelet Rehabil. 2021;34(4):707-714. doi: 10.3233/BMR-200260.
Kinematic analysis has been a dominant tool for addressing the neuromuscular and proprioceptive alterations that occur in Low Back Pain (LBP) patients. Movement variability is a crucial component of this analysis. In the recent years application of non-linear indices seems to be showing the way.
The aim of the study was to compare movement variability, as expressed mainly by non-linear indices, at the pelvis and lumbar spine between LBP patients and healthy participants during gait.
Sixteen (16) LBP patients and thirteen (13) healthy control subjects (non-athletes) participated in the study. Participants walked on a treadmill at different walking conditions while recorded by a 6-infrared camera optoelectronic system. Kinematic variability of pelvic and lumbar movement was analyzed using linear (standard deviation - SD) and non-linear indices (Maximal Lyapunov Exponent - LyE and Approximate Entropy - ApEn).
Healthy subjects were found to have significantly greater mean values than LBP patients at seven pelvic and lumbar components in LyE, ApEn and SD. Specifically, the calculated LyE at the pelvis during normal gait was proven to have a sensitivity of 92.3% and a specificity of 90% in the discrimination of healthy subjects from LBP patients. Female subjects presented with higher variability in gait measures than males.
Healthy participants presented with higher movement variability in their kinematic behavior in comparison to LBP patients. Lower variability values may be partly explained by the attempt of LBP patients to avoid painful end of range of motion positions. In this perspective non-linear indices seem to relate to qualitive characteristics of movement that need to be taken into consideration during rehabilitation.
运动学分析一直是解决腰痛（LBP）患者出现的神经肌肉和本体感觉改变的主要工具。运动可变性是这种分析的一个关键组成部分。近年来，非线性指标的应用似乎显示出了一种趋势。
本研究的目的是比较 LBP 患者和健康参与者在步态中骨盆和腰椎的运动可变性，主要表现为非线性指标。
16 名 LBP 患者和 13 名健康对照组（非运动员）参加了研究。参与者在跑步机上以不同的行走条件行走，同时通过 6 个红外摄像头光电系统进行记录。使用线性（标准差-SD）和非线性指标（最大 Lyapunov 指数-LyE 和近似熵-ApEn）分析骨盆和腰椎运动的可变性。
健康受试者在 LyE、ApEn 和 SD 的七个骨盆和腰椎成分上的平均值明显大于 LBP 患者。具体来说，在正常步态下计算的骨盆 LyE 被证明在区分健康受试者和 LBP 患者方面具有 92.3%的敏感性和 90%的特异性。女性受试者在步态测量中的可变性高于男性。
与 LBP 患者相比，健康参与者的运动行为表现出更高的运动可变性。较低的可变性值部分可能是由于 LBP 患者试图避免疼痛的运动范围末端位置。从这个角度来看，非线性指标似乎与运动的定性特征有关，在康复过程中需要考虑这些特征。
