Handel M, Horstmann T, Dickhuth H H, Gülch R W
Institute of Physiology II, University of Tübingen, Germany.
Eur J Appl Physiol Occup Physiol. 1997;76(5):400-8. doi: 10.1007/s004210050268.
The effects of an 8-week unilateral contract-relax (CR) stretching training program (passive stretch after isometric contraction) on muscular performance were investigated in a group of 16 athletes. The flexibility, maximum torque and angular position as well as contraction work in movements of the knee joint were determined before training and after 4 and 8 weeks of training. The torque measurements were performed under isokinetic conditions, eccentrically at angular velocities of 60 degrees x s(-1) and 120 degrees x s(-1), isometrically at five different joint positions, and concentrically at angular velocities of 60, 120, 180 and 240 degrees x s(-1) using an isokinetic dynamometer. A surface electromyogram (EMG) of the thigh muscles (quadriceps and hamstrings) was recorded simultaneously. As compared to untrained control limbs, significant improvements in active and passive flexibility (up to 6.3 degrees in range of motion), maximum torque (up to 21.6%) and work (up to 12.9%) were observed, and these were especially pronounced under eccentric load conditions. A comparison between integrated EMG recordings during eccentric and concentric loads, as well as the interpretation of the training-induced changes in the EMG, suggest that muscular activity under eccentric loads may be impaired by mental processes.
在16名运动员中研究了为期8周的单侧收缩-放松（CR）拉伸训练计划（等长收缩后进行被动拉伸）对肌肉性能的影响。在训练前以及训练4周和8周后，测定了膝关节运动中的灵活性、最大扭矩、角位置以及收缩功。扭矩测量在等速条件下进行，分别在角速度为60度×秒⁻¹和120度×秒⁻¹时进行离心测量，在五个不同关节位置进行等长测量，以及在角速度为60、120、180和240度×秒⁻¹时进行向心测量，使用等速测力计。同时记录大腿肌肉（股四头肌和腘绳肌）的表面肌电图（EMG）。与未训练的对照肢体相比，观察到主动和被动灵活性（运动范围提高多达6.3度）、最大扭矩（提高多达21.6%）和功（提高多达12.9%）有显著改善，并且这些在离心负荷条件下尤为明显。对离心和向心负荷期间的积分肌电图记录进行比较，以及对训练引起的肌电图变化的解释表明，离心负荷下的肌肉活动可能会受到心理过程的损害。
