Akataki K, Mita K, Itoh K, Ono Y, Oki T, Ishida N
Institute for Developmental Research, Aichi Prefectural Colony, Kasugai, Japan.
Front Med Biol Eng. 1995;6(4):281-9.
This study was designed to develop a new index of muscle strength for children that was independent of body weight thus accommodated their developmental changes and to assess the quadriceps strength influencing ambulatory status in children with spina bifida. Maximum voluntary strength in isometric knee extension was measured from 60 children with spina bifida and 92 normal children. The measured strength was described in terms of torque. A muscle strength index (MSI) was defined as a unitless measure independent of the subject's body weight (i) by normalizing the residual of the maximum torque from the developmental regression line for normal children by body weight and, furthermore, (ii) by dividing the normalized residuals by their standard deviation among normal children. Children with spina bifida demonstrated a tendency to increase in maximum quadriceps torque with body weight; however, spina bifida children with a body weight above 30 kg showed a progressive decrease in MSI below a normal limit of muscle weakness. The MSI was closely related to both neurologic level and ambulatory ability compared with the maximum torque. These findings suggest MSI provides useful and detailed information for assessing and predicting ambulatory ability in children with spina bifida.
本研究旨在开发一种新的儿童肌肉力量指数，该指数独立于体重，从而适应其发育变化，并评估影响脊柱裂儿童步行状态的股四头肌力量。对60名脊柱裂儿童和92名正常儿童进行了等长膝关节伸展的最大自主力量测量。测量的力量用扭矩来描述。肌肉力量指数（MSI）被定义为一种与受试者体重无关的无量纲测量指标：（i）通过将正常儿童发育回归线的最大扭矩残差按体重进行归一化，并且（ii）通过将归一化残差除以其在正常儿童中的标准差。脊柱裂儿童表现出最大股四头肌扭矩随体重增加的趋势；然而，体重超过30 kg的脊柱裂儿童的MSI逐渐下降至低于肌肉无力的正常限度。与最大扭矩相比，MSI与神经学水平和步行能力均密切相关。这些发现表明，MSI为评估和预测脊柱裂儿童的步行能力提供了有用且详细的信息。
