Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Germany.
Int J Sports Med. 2010 Apr;31(4):243-50. doi: 10.1055/s-0029-1242813. Epub 2010 Feb 23.
This study examined squat jumping (SJ) mechanics following length restricted strength training regimens of the knee extensors and flexors. SJ from a 110 degrees knee joint angle starting position and isometric moment-knee angle relations of knee extensors and flexors were analysed in 16 athletes before and directly after 8 weeks of strength training regimens that were restricted to knee joint angles corresponding to long muscle-tendon unit (MTU) length for the knee extensors and flexors. SJ mechanics were studied using a two-dimensional kinematic model with three rigid bodies (upper leg, lower leg, foot) in combination with force plates measurements of ground reaction force in the right and left lower extremity. Centre of mass jumping height significantly (p<0.05) increased post training, but this was not explained by enhanced absolute power generation in the knee joint. However, post training small but significant (p<0.05) shifts to smaller knee joint angles occurred in the normalized [% Max.] knee joint angle dependent power generation in the right and left knee joint during SJ. The isometric moment-knee angle relation of the knee extensors was also significantly (p<0.05) shifted to longer MTU lengths of knee extensors. Length restricted strength training may alter the mechanical situation during both isometric contractions and dynamic athletic movements.
本研究考察了限制膝关节伸肌和屈肌强度训练方案后深蹲跳（SJ）的力学性能。从 110 度膝关节角度开始进行 SJ，并分析了 16 名运动员在 8 周的强度训练方案前后的等长力矩-膝关节角度关系，这些方案限制在与膝关节伸肌和屈肌长肌腱-肌腱单位（MTU）长度对应的膝关节角度。使用二维运动学模型和三个刚体（大腿、小腿、脚）结合左右下肢地面反作用力的力板测量来研究 SJ 力学。训练后，质心跳跃高度显著增加（p<0.05），但这并不是由于膝关节绝对功率生成增强所致。然而，在 SJ 过程中，左右膝关节的归一化 [%Max.]膝关节角度依赖性功率生成中，膝关节角度的小但显著（p<0.05）的变化发生在较小的膝关节角度。膝关节伸肌的等长力矩-膝关节角度关系也显著（p<0.05）向更长的膝关节伸肌 MTU 长度转移。限制长度的力量训练可能会改变等长收缩和动态运动过程中的力学情况。
