Abstract Aims: To establish anthropometric-related percentile curves for muscle size and strength in a cohort of typically developing (TD) children and to demonstrate their use through applications in children with cerebral palsy (CP) and Duchenne muscular dystrophy (DMD). Methods: Lower limb muscle size and strength were assessed in a large cross-sectional cohort of TD children with 3D freehand ultrasound (four muscles, n=154, ♂/♀=82/72, age range: 0y7mo-17y10mo) and fixed dynamometry (seven muscle groups, n=153, ♂/♀=108/45, age range: 4y6mo-16y1mo), respectively. Generalized additive models for location, scale and shape were used to estimate anthropometric-related, i.e. body mass and height, TD percentile curves and to convert outcomes of individual patients with CP and DMD into z-scores. Results: Muscle size and strength, as well as their inter-subject variation, increased with increasing anthropometric values. Individual patients exhibited negative z-scores, indicating muscle size and strength deficits in reference to TD peers. Interpretation: The established anthropometric-related percentile curves for muscle size and strength in a cohort of TD children can successfully be used to express patient outcomes in reference to TD. This facilitates the interpretation of muscle size and weakness in children with a motor disability and allows for the evaluation of the disease progression and treatment impact during growth.

中文翻译：

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典型发育儿童下肢肌肉大小和强度的人体测量相关百分位数曲线

摘要 目的：建立一组典型发育（TD）儿童的肌肉大小和力量的人体测量相关百分位曲线，并通过在脑瘫（CP）和杜氏肌营养不良（DMD）儿童中的应用来证明其用途。方法：使用 3D 徒手超声（四块肌肉，n=154，♂/♀=82/72，年龄范围：0y7mo-17y10mo）和固定测力法对 TD 儿童的下肢肌肉大小和力量进行评估（七个肌肉群，n=153，♂/♀=108/45，年龄范围：4y6mo-16y1mo）。位置、尺度和形状的广义相加模型被用来估计人体测量相关的，即体重和身高、TD百分位数曲线，并将患有CP和DMD的个体患者的结果转换成z分数。结果：肌肉大小和力量及其个体间差异随着人体测量值的增加而增加。个别患者表现出负 z 分数，表明与 TD 同龄人相比，肌肉尺寸和力量存在缺陷。解释：在 TD 儿童队列中建立的与人体测量相关的肌肉大小和力量百分位数曲线可以成功地用于表达与 TD 相关的患者结果。这有助于解释运动障碍儿童的肌肉大小和肌无力，并可以评估生长过程中的疾病进展和治疗影响。