Erlandson M C, Hounjet S, Treen T, Lanovaz J L
a College of Kinesiology , University of Saskatchewan , Saskatoon , Canada.
J Sports Sci. 2018 Jul;36(14):1640-1647. doi: 10.1080/02640414.2017.1407438. Epub 2017 Dec 4.
Weight bearing (WB) activity is important for healthy skeletal development. The magnitude of loading during WB activities, especially upper limb impacts, has yet to be quantified in children. This study quantifies ground reaction forces (GRF) experienced by children performing WB activities and examines the contribution of body weight (BW) to GRF. Fifty children, aged 8-12 were recruited (34 males). GRF were measured using force plates during 20 upper and lower limb activities (such as landing on the feet and hands). Sex differences in GRF and associations between peak force and BW were examined using independent sample t-tests and linear regressions (p < 0.05), respectively. Lower limb GRF varied from 2-6x BW with no significant sex differences. GRF during upper limb activities varied from 1/3-1.7x BW with males experiencing significantly greater GRF for 25% of activities. BW was significantly associated with peak force in almost all activities; however, GRF variation explained by BW was wide-ranging across activities and not dependent on limb or activity type (static vs dynamic). Therefore, factors other than BW, such as technique, may be important in determining forces experienced by children performing WB activity and should be considered when choosing activities for WB activity interventions.
负重（WB）活动对健康的骨骼发育很重要。儿童负重活动期间的负荷大小，尤其是上肢冲击，尚未得到量化。本研究量化了进行负重活动的儿童所经历的地面反作用力（GRF），并研究了体重（BW）对GRF的贡献。招募了50名8至12岁的儿童（34名男性）。在20项上肢和下肢活动（如用脚和手着地）期间使用测力板测量GRF。分别使用独立样本t检验和线性回归（p<0.05）来检验GRF的性别差异以及峰值力与BW之间的关联。下肢GRF在2至6倍BW之间变化，无显著性别差异。上肢活动期间的GRF在1/3至1.7倍BW之间变化，男性在25%的活动中经历的GRF显著更大。BW在几乎所有活动中都与峰值力显著相关；然而，BW所解释的GRF变化在不同活动中差异很大，且不取决于肢体或活动类型（静态与动态）。因此，除BW之外的因素，如技术，在确定进行负重活动的儿童所经历的力时可能很重要，并且在选择负重活动干预的活动时应予以考虑。
