Study on the Influence of Elastic Compression Pants Elasticity and Movement Speed on Human Joint Protection

The aim of this study was to clarify how human movement speed and pants elasticity affect the athletic performance of knee joint protection by testing pants with different elastic properties: CP1 (tight pants) and CP2&CP3 (elastic compression pants), which reinforce the knee joint. In addition, CS (cotton sport pants) was developed as a control garment. Three subjects wore CP1, CP2, CP3 and CS while running on the treadmill at three kinds of human movement speed. A three-dimensional motion capture instrument was used to capture the three-dimensional trajectory of the marked points of lower limbs. As a result, the influence of the movement speed on the kinematic parameters (AKJ & gait cycle) was more obvious than the fabric elasticity. If elastic pants are worn during running, the change of AKJ will be stable with the increase of speed. When non-elastic pants are worn, the effect is opposite. Not only that, elastic compression pants are efficient in reducing the motion amplitude of the knee joint during the suspension period as far as 41°, making it highly practical in terms of stability. That is, the elastic fabric can protect the joints when the lower limbs are in motion. Moreover, with the increase of speed and elasticity, the elastic pants can reduce the gait cycle by up to 22% compared with non-elastic pants alone. Through the kinematics mechanism of human joints, these findings may translate into an effect on protective performance and a reduction in sport injuries. Therefore, it is necessary to wear elastic pants, especially compression pants, when running at higher speed, as the average gait cycle gradually decreases. This research shows that the knee joint protection functions of elastic compression garments differ according to the level of elasticity and differential movement speed, providing theoretical support for designing and producing elastic compression pants. It also acts as a guide for the research of lower limb joint protection.