Background

Increment of lumbar lordosis, a frequent spinal finding in Duchenne Muscular Dystrophy (DMD), is a compensatory mechanism secondary to muscle weakness. However, excessive lumbar lordosis may change the position of the center of mass, and lead to balance and walking difficulties.

Objective

To study the relationship between factors that may influence ambulatory function in boys with DMD and to investigate the effects of lumbar lordosis increment on gait and balance perturbations.

Methods

Twenty-one ambulant patients with DMD and 10 healthy boys were included. Lumbar lordosis and thoracic kyphosis angles, dynamic and static balance tests, ambulatory function, muscle strength, and disease severity were assessed. Usage of steroids and orthotic devices were recorded. Scoliosis was assessed on radiographs. Receiver operator characteristic curves were formed and area under curve (AUC) measurements were performed to assess the ability of the tests to discriminate ambulatory status and optimal cut-off values were established according to the Youden index.

Results

The amount of lumbar lordosis correlated strongly and negatively with quality of ambulation (r = −0.710) and moderately with performance on balance tests. The strength of both upper limbs and lower limbs muscles were not associated with any of the variables. According to the AUC analysis, patients with a lumbar lordosis higher than 36° had worse scores on gait and dynamic balance tests.

Conclusion

Ambulation and dynamic balance are negatively affected by the increment of lumbar lordosis with a cut-off point of 36°in boys with DMD.

中文翻译：

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腰椎前凸增加对杜氏肌营养不良男孩步态恶化的影响：一项横断面研究

背景

腰椎前凸增加是杜氏肌营养不良症 (DMD) 中常见的脊柱表现，是继发于肌肉无力的一种代偿机制。但是，过度的腰椎前凸可能会改变重心的位置，导致平衡和行走困难。

客观的

研究可能影响DMD男孩步行功能的因素之间的关系，并研究腰椎前凸增加对步态和平衡扰动的影响。

方法

包括 21 名可走动的 DMD 患者和 10 名健康男孩。评估腰椎前凸和胸椎后凸角度、动态和静态平衡测试、行走功能、肌肉力量和疾病严重程度。记录类固醇和矫形器的使用情况。脊柱侧弯是通过射线照片评估的。形成接收操作者特征曲线，并进行曲线下面积 (AUC) 测量以评估测试区分行走状态的能力，并根据约登指数确定最佳截止值。

结果

腰椎前凸量与行走质量（r  = -0.710）强烈且负相关，与平衡测试表现中度相关。上肢和下肢肌肉的力量与任何变量均无关。根据 AUC 分析，腰椎前凸度高于 36° 的患者在步态和动态平衡测试中得分较差。

结论

行走和动态平衡受到 DMD 男孩腰椎前凸增加的负面影响，截止点为 36°。