KINEMATIC ANALYSIS BY GENDER IN DIFFERENT JUMP TESTS BASED ON A SMARTPHONE INERTIAL SENSOR

ABSTRACT Introduction: Vertical jump tests can be used as estimators of muscular power, physical capacity, motor development and functional capacity. The ability to jump can be analyzed with different methods, including the use of inertial sensors. Objective: To describe and analyze kinematic characteristics using the inertial sensor integrated into the iPhone 4S® and jump contact mat variables in the squat jump (SJ) and countermovement jump (CMJ) tests, and to determine the interaction between kinetic and kinematic variables. Methods: A cross-sectional study was conducted with 27 healthy young adults. The primary outcome measures were linear acceleration, flight time, contact time, jump height and dynamometry of the knee extensors. Spearman's rho was used to investigate the correlation between variables. The Mann–Whitney U rank-sum test was used for the analysis of intergender variance. Results: The greatest difference between groups (gender) was in the dynamometry variables (p<0.001) and contact mat variables (p<0.001). Between the jump tests, the greatest difference between groups (gender) was in the CMJ test (p<0.001). Conclusion: The inertial sensor embedded in the smartphone demonstrated a correlation with the jump mat and the dynamometry. Finally, the higher kinetic and kinematic scores observed in the jumps performed by male participants than in those performed by female participants suggest that they can be used to better characterize their jumping profile. Level of Evidence IV; Diagnostic Studies - Investigating a Diagnostic Test.

摘要
引言：垂直跳跃测试可作为肌肉力量、身体机能、运动发育与功能能力的评估指标。跳跃能力可通过多种方法分析，其中包括惯性传感器（inertial sensor）的应用。
研究目的：本研究旨在利用集成于iPhone 4S®的惯性传感器，对深蹲跳（Squat Jump, SJ）与反向跳跃（Countermovement Jump, CMJ）测试中的运动学特征及跳跃接触垫变量进行描述与分析，并探究动力学与运动学变量间的相互作用。
研究方法：本研究纳入27名健康青年成年人开展横断面研究。主要结局指标包括线性加速度、腾空时间、接触时间、跳跃高度以及膝伸肌肌力测定结果。采用斯皮尔曼rho系数（Spearman's rho）分析变量间的相关性，采用曼-惠特尼U秩和检验（Mann–Whitney U rank-sum test）分析性别间差异。
研究结果：两组（性别）间的最大差异出现在肌力测定变量（p<0.001）与接触垫测试变量（p<0.001）中。在不同跳跃测试中，两组间的最大差异出现在反向跳跃（CMJ）测试中（p<0.001）。
研究结论：本研究证实，集成于智能手机的惯性传感器与跳跃垫测试结果及肌力测定结果存在相关性。最终，男性受试者在各项跳跃测试中展现出的动力学与运动学评分均高于女性受试者，提示上述指标可用于更精准地刻画受试者的跳跃能力特征。
证据等级IV；诊断性研究——诊断测试相关研究。