Brown E W, Abani K
Med Sci Sports Exerc. 1985 Oct;17(5):554-66.
This study documented characteristics of the dead lift of teenage lifters. Films of 10 "skilled" and 11 "unskilled" contestants in a Michigan Teenage Powerlifting Championship provided data for analysis. Equations of motion, force, and moments were developed for a multisegment model of the lifters' movement in the sagittal plane and applied to the film data. Analysis was limited to 1) body segment orientations, 2) vertical bar accelerations, 3) vertical joint reaction forces, 4) segmental angular accelerations, 5) horizontal moment arms of the bar to selected joints, and 6) intersegmental resultant moments. Significant differences (P less than 0.05) in body segment orientation indicated a more upright posture at lift-off in the skilled group. Maximum vertical bar acceleration and angular acceleration of the trunk tended to occur near lift-off in the skilled lifters. The unskilled subjects demonstrated greater variability and magnitude in linear and angular acceleration parameters. In all lifters, maximum vertical force was experienced at the ankle joint. Within each subject, the hip joint experienced the greatest torque because of the relatively large horizontal moment arm of the bar (dominant mass in the system) to this joint. In all subjects, the magnitude of the mass lifted, and not the technique, was the primary determinant in the intersegmental resultant moment acting at the hip and the vertical force experienced at the ankle, knee, and hip joints.
本研究记录了青少年举重运动员硬拉的特征。密歇根青少年力量举重锦标赛中10名“熟练”和11名“不熟练”参赛者的影片提供了分析数据。针对举重运动员矢状面运动的多节段模型建立了运动方程、力方程和力矩方程，并应用于影片数据。分析限于：1）身体节段方位；2）杠铃垂直加速度；3）垂直关节反作用力；4）节段角加速度；5）杠铃至选定关节的水平力臂；6）节段间合力矩。身体节段方位的显著差异（P小于0.05）表明熟练组在起始时姿势更直立。熟练举重运动员的最大杠铃垂直加速度和躯干角加速度往往在起始时出现。不熟练受试者在直线和角加速度参数方面表现出更大的变异性和幅度。在所有举重运动员中，踝关节承受最大垂直力。在每个受试者中，由于杠铃（系统中的主要质量）至该关节的水平力臂相对较大，髋关节承受最大扭矩。在所有受试者中，举起的质量大小而非技术，是作用于髋关节的节段间合力矩以及踝关节、膝关节和髋关节所承受垂直力的主要决定因素。
