Physical Education and Sports Science, National Institute of Education, Nanyang Technological University, Singapore.
College of Art and Design, Shaanxi University of Science and Technology, Xi'an, China.
J Sports Sci. 2024 Jun;42(12):1147-1156. doi: 10.1080/02640414.2024.2386211. Epub 2024 Aug 1.
This study examines the effects of limb dominance and lead limb in task initiation on the kinetics and kinematics of step-off drop landings. Nineteen male participants performed drop landings led by the dominant and non-dominant limbs at 45-cm and 60-cm drop heights. Ground reaction force (GRF) and lower body kinematic data were collected. Between-limb time differences at the initial ground contact were calculated to indicate temporal asymmetry. Statistical Parametric Mapping (SPM) was applied for waveform analysis while two-way repeated measures ANOVA was used for discrete parameters. SPM results revealed greater GRF and lesser ankle dorsiflexion in the lead limb compared to the trail limb in 3 out of 4 landing conditions. The dominant limb displayed a greater forefoot loading rate (45 cm: =.009, = 0.438; 60 cm: =.035, = 0.225) and greater ankle joint quasi-stiffness (45 cm: < .001, = 0.360; 60 cm: < .001, = 0.597) than the non-dominant limb. Not all 380 trials were lead-limb first landings, with a smaller between-limb time difference (=.009, = 0.60) at 60 cm (4.1 ± 2.3 ms) than 45 cm (5.6 ± 2.7 ms). In conclusion, the step-off drop landing is not an ideal protocol for examining bilateral asymmetry in lower limb biomechanics due to potential biases introduced by limb dominance and the step-off limb.
本研究考察了起始任务时的肢体优势和主导肢体对台阶式跳下着陆动力学和运动学的影响。19 名男性参与者分别以优势腿和非优势腿在 45cm 和 60cm 的跳下高度进行跳下着陆。采集地面反作用力（GRF）和下半身运动学数据。通过计算初始地面接触时的两腿之间的时间差来表示时间不对称性。统计参数映射（SPM）用于波形分析，而双向重复测量方差分析用于离散参数。SPM 结果显示，在 4 种着陆条件中的 3 种中，主导腿的 GRF 更大，踝关节背屈更小。在 380 次试验中，主导腿的前脚加载率更大（45cm：=.009， = 0.438；60cm：=.035， = 0.225），踝关节准刚度更大（45cm： < .001， = 0.360；60cm： < .001， = 0.597）。并非所有 380 次试验都是主导腿先着陆，60cm（4.1 ± 2.3 ms）的两腿之间的时间差小于 45cm（5.6 ± 2.7 ms）（= .009， = 0.60）。总之，由于肢体优势和台阶式着陆腿引入的潜在偏差，台阶式跳下着陆不是检查下肢生物力学双侧不对称性的理想方案。
