Patients with Duchenne muscular dystrophy (DMD) develop skeletal muscle weakness and cardiomyopathy. Validated skeletal muscle outcome measures are limited to ambulatory patients, but most DMD patients in cardiac trials are non-ambulatory. New objective functional assessments are needed. This study's objective was to assess the correlation and longitudinal change of two measures: quantitative muscle testing (QMT) and accelerometry. Patients with DMD were prospectively enrolled and underwent QMT and wore wrist and ankle accelerometers for seven days at baseline, 1-, and 2-years. QMT measures were indexed to age. Accelerometer recordings were total vector magnitudes and awake vector magnitude. Correlations were assessed using a Spearman correlation, and longitudinal change was evaluated using a paired t-test or a Wilcoxon signed rank test. Forty-eight participants were included. QMT and accelerometry measures had a moderate or strong correlation, particularly indexed arm QMT with total wrist vector magnitude (rho=0.85, p<0.001), total indexed QMT with total wrist vector magnitude (rho=0.8, p<0.001) and indexed leg QMT with total ankle vector magnitude (rho=0.69, p<0.001). QMT and accelerometry measures declined significantly over time. Accelerometry correlates with QMT and indexed QMT in boys with DMD. A combination of QMT and accelerometry may provide a complementary assessment of skeletal muscle function in non-ambulatory boys with DMD.

中文翻译：

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超越步行：测量患有杜兴氏肌营养不良症的青年人的身体活动

杜氏肌营养不良症 (DMD) 患者会出现骨骼肌无力和心肌病。经过验证的骨骼肌结果测量仅限于门诊患者，但心脏试验中的大多数 DMD 患者是非门诊患者。需要新的客观功能评估。本研究的目的是评估两种测量的相关性和纵向变化：定量肌肉测试 (QMT) 和加速度计。DMD 患者被前瞻性地纳入并接受 QMT，并在基线、1 年和 2 年时佩戴手腕和脚踝加速度计 7 天。QMT 措施与年龄挂钩。加速度计记录是总矢量幅度和清醒矢量幅度。使用 Spearman 相关性评估相关性，并使用配对 t 检验或 Wilcoxon 符号秩检验评估纵向变化。包括四十八名参与者。QMT 和加速度计测量具有中度或强相关性，特别是索引手臂 QMT 与总手腕矢量幅度（rho=0.85，p<0.001），总索引 QMT 与总手腕矢量幅度（rho=0.8，p<0.001）和索引腿QMT 与全踝矢量幅度 (rho=0.69, p<0.001)。随着时间的推移，QMT 和加速度计测量值显着下降。加速度计与患有 DMD 的男孩的 QMT 和索引 QMT 相关。QMT 和加速度计的组合可以为患有 DMD 的非卧床男孩的骨骼肌功能提供补充评估。带有总手腕矢量幅度的总索引 QMT（rho=0.8，p<0.001）和带有总脚踝矢量幅度的索引腿 QMT（rho=0.69，p<0.001）。随着时间的推移，QMT 和加速度计测量值显着下降。加速度计与患有 DMD 的男孩的 QMT 和索引 QMT 相关。QMT 和加速度计的组合可以为患有 DMD 的非卧床男孩的骨骼肌功能提供补充评估。带有总手腕矢量幅度的总索引 QMT（rho=0.8，p<0.001）和带有总脚踝矢量幅度的索引腿 QMT（rho=0.69，p<0.001）。随着时间的推移，QMT 和加速度计测量值显着下降。加速度计与患有 DMD 的男孩的 QMT 和索引 QMT 相关。QMT 和加速度计的组合可以为患有 DMD 的非卧床男孩的骨骼肌功能提供补充评估。