Loverro Kari L, Khuu Anne, Kao Pei-Chun, Lewis Cara L
Department of Physical Therapy & Athletic Training, PhD Program in Rehabilitation Sciences, College of Health & Rehabilitation Sciences: Sargent College, Boston University, 635 Commonwealth Ave., Boston, MA, United States; Natick Soldier Research Development and Engineering Center, 10 General Greene Ave., Natick, MA, United States.
Department of Physical Therapy & Athletic Training, PhD Program in Rehabilitation Sciences, College of Health & Rehabilitation Sciences: Sargent College, Boston University, 635 Commonwealth Ave., Boston, MA, United States.
Gait Posture. 2019 Feb;68:545-554. doi: 10.1016/j.gaitpost.2019.01.007. Epub 2019 Jan 7.
Individuals with developmental dysplasia of the hip (DDH) often report hip pain and exhibit gait adaptations. Previous studies in this patient population have focused on average kinematic and acceleration measures during gait, but have not examined variability.
Do individuals with hip pain and DDH have altered kinematic variability or local dynamic stability (LDS) compared to individuals without hip pain?
Twelve individuals with hip pain and DDH and 12 matched controls walked for two minutes on a treadmill at three speeds: preferred, fast (25% faster than preferred), and prescribed (1.25 m/s). Kinematic variability of spatiotemporal measures, joint and segment angles, and LDS of the trunk were calculated for each speed.
At the prescribed speed, individuals with hip pain and DDH had more kinematic variability than controls at the hip, pelvis, and trunk as well as greater variability in spatiotemporal measures. LDS was not different between groups. Kinematic variability of the joints decreased and LDS of the trunk increased (i.e., increased gait stability) with increased speed.
Individuals with hip pain and DDH had greater kinematic variability compared to individuals without hip pain when walking at the same prescribed speed, indicating either an adaptation to pain or reduced neuromuscular control. LDS of the trunk was not different between groups, suggesting that hip pain does not affect overall gait stability. Kinematic variability and LDS were affected by walking speed, but in different ways, emphasizing that these measures quantify different aspects of walking behavior.
髋关节发育不良（DDH）患者常报告髋关节疼痛并表现出步态适应性改变。此前针对该患者群体的研究主要关注步态期间的平均运动学和加速度测量，但未考察变异性。
与无髋关节疼痛的个体相比，有髋关节疼痛的DDH患者的运动学变异性或局部动态稳定性（LDS）是否发生改变？
12名有髋关节疼痛的DDH患者和12名匹配的对照者在跑步机上以三种速度行走两分钟：偏好速度、快速（比偏好速度快25%）和规定速度（1.25米/秒）。计算每种速度下时空测量、关节和节段角度的运动学变异性以及躯干的LDS。
在规定速度下，有髋关节疼痛的DDH患者在髋关节、骨盆和躯干处的运动学变异性比对照组更大，在时空测量方面的变异性也更大。两组之间的LDS没有差异。随着速度增加，关节的运动学变异性降低，躯干的LDS增加（即步态稳定性增加）。
在相同规定速度行走时，有髋关节疼痛的DDH患者比无髋关节疼痛的个体具有更大的运动学变异性，这表明要么是对疼痛的适应，要么是神经肌肉控制能力下降。两组之间躯干的LDS没有差异，这表明髋关节疼痛不影响整体步态稳定性。运动学变异性和LDS受行走速度影响，但方式不同，这强调了这些测量量化了步行行为的不同方面。
