PURPOSE Muscle power is a component of muscular fitness and is proportional to its volume. Reduced muscular fitness in children is linked to negative health outcomes. Associations between muscle volume (MV) and power have not been examined in young children and could reveal important insights into early neuromuscular development. METHOD Forty-four children (2-8 y) completed 3 tests of short-term muscular power: repeated anaerobic sprint test, vertical jump, and horizontal jump. MV was assessed using 3D ultrasound for 3 lower limb muscles (rectus femoris, medial gastrocnemius, and tibialis anterior) and summed for across legs. Associations between muscular power and summed MV were assessed using Pearson correlation (r). Sex-based differences in muscular power and MV were assessed using 1-way analysis of covariance. RESULTS Moderate-strong associations (r = .57 - .87) were found between muscular power and summed MV. No differences were found between boys and girls for height, weight, MV, or muscular power. CONCLUSIONS Young children who have larger lower limb muscles perform better at tasks dependent on short-term muscular power, such as running and jumping, compared with children with smaller muscles. Sex-based differences in short-term muscular power do not exist in young children and reflect similar anthropometry, including lower limb MV.

中文翻译：

---

短期肌肉力量与幼儿下肢肌肉量有关。

目的肌肉力量是肌肉健康的一个组成部分，与其体积成正比。儿童肌肉健康度下降与负面健康结果有关。肌肉体积 (MV) 和力量之间的关联尚未在幼儿中进行过研究，这可能揭示对早期神经肌肉发育的重要见解。方法 44 名儿童（2-8 岁）完成了 3 项短期肌力测试：重复无氧冲刺测试、垂直跳跃和水平跳跃。使用 3D 超声评估 3 块下肢肌肉（股直肌、腓肠肌内侧和胫骨前肌）的 MV，并对跨腿求和。使用 Pearson 相关性 (r) 评估肌肉力量和总 MV 之间的关联。使用协方差的单向分析评估肌肉力量和 MV 中基于性别的差异。结果 在肌肉力量和总 MV 之间发现了中等强度的关联 (r = .57 - .87)。男孩和女孩在身高、体重、MV 或肌肉力量方面没有差异。结论 与肌肉较小的儿童相比，下肢肌肉较大的幼儿在依赖短期肌肉力量的任务中表现更好，例如跑步和跳跃。短期肌肉力量的性别差异在幼儿中不存在，反映了相似的人体测量学，包括下肢 MV。与肌肉较小的儿童相比。短期肌肉力量的性别差异在幼儿中不存在，反映了相似的人体测量学，包括下肢 MV。与肌肉较小的儿童相比。短期肌肉力量的性别差异在幼儿中不存在，反映了相似的人体测量学，包括下肢 MV。