Nelson Alexis K, Fong Hailey, Carnall Alexander M, Puppa Melissa J, Beeler Derek, Stickley Cris, Mihalko William, Powell Douglas W
Interdisciplinary Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN, USA.
College of Health Sciences, University of Memphis, Memphis, TN, USA.
Int J Exerc Sci. 2023 Aug 1;16(1):942-953. doi: 10.70252/YBRI4742. eCollection 2023.
The purpose of this study was to investigate the influence of simulated changes in body mass on lower extremity joint work and relative joint contributions during stair descent. Ten healthy recreationally active college-age participants performed five stair descent trials in each of five loading conditions: no added load and with an additional 5%, 10%, 15% and 20% of their body weight. Three-dimensional ankle, knee and hip joint powers were calculated using a six degree-of-freedom model in Visual3D (C-Motion Inc., Germantown, MD, USA). Sagittal plane joint work was calculated as the joint power curve integrated with respect to time during the period between initial contact and toe off. Prism 9.0 (GraphPad Inc., San Diego, CA) was used to perform univariate 1 × 5 repeated measures analyses of variance to determine the effect of added mass on absolute and relative joint work values for total and for each lower extremity joint independently. Increasing added mass was associated with greater total lower extremity negative work during the stair descent task ( 0.001). At the ankle, increasing added mass was associated with increasing magnitudes of negative joint work. Increasing added mass was associated with greater relative contributions of the ankle and reduced knee contributions to total negative lower extremity joint work ( 0.014 and 0.006). The current findings demonstrated increases in ankle joint contributions to total lower extremity work while knee joint contributions to total lower extremity work were reduced in response to increasing added mass.
本研究的目的是调查模拟体重变化对下楼梯时下肢关节功及相对关节贡献的影响。十名健康、有休闲运动习惯的大学生参与者在五种负荷条件下各进行五次下楼梯试验：无额外负荷以及额外增加其体重的5%、10%、15%和20%。使用Visual3D（美国马里兰州日耳曼敦市C-Motion公司）中的六自由度模型计算三维踝关节、膝关节和髋关节功率。矢状面关节功计算为从初始接触到足趾离地期间关节功率曲线相对于时间的积分。使用Prism 9.0（美国加利福尼亚州圣地亚哥市GraphPad公司）进行单变量1×5重复测量方差分析，以确定增加的质量对总下肢以及每个下肢关节的绝对和相对关节功值的影响。在下楼梯任务中，增加的质量与更大的总下肢负功相关（P<0.001）。在踝关节处，增加的质量与负关节功大小的增加相关。增加的质量与踝关节对总下肢负关节功的相对贡献增加以及膝关节贡献减少相关（P分别为0.014和0.006）。当前研究结果表明，随着增加的质量增加，踝关节对总下肢功的贡献增加，而膝关节对总下肢功的贡献减少。
