Background. Tai chi is recognized worldwide for its rehabilitation abilities and healthcare benefits. However, in recent years, some movements associated with tai chi have been shown to damage the lower limb joints. The purpose of this study was to investigate and compare the effects of different movements, postures, center of mass (COM) movements, and range of knee movement of tai chi exercises on knee joint load. Methods. Fourteen professional tai chi practitioners in two postures (high and low) were enrolled to perform the following four typical tai chi movements: wild horse’s mane (WHM), repulse monkey (RM), wave-hand in cloud (WHIC), and grasp the bird’s tail (GBT). Kinematic and kinetics data were synchronously collected using the Vicon infrared high-speed motion capture system and a three-dimensional (3D) force measurement platform. Variance analysis and partial correlation analysis were performed to investigate factors influencing peak knee joint moment and vertical ground reaction force (VGRF). Results. The results showed that the peak knee extension and abduction moment were larger in WHM and RM than those in WHIC and GBT ( ). WHM was associated with greater rotation moment than the other typical movements ( ). VGRF and joint moment among different poses were significantly different. Low-pose tai chi typical movements were associated with greater VGRF, knee joint extension and abduction, and rotation moments than high-pose movements ( ). The anteroposterior and mediolateral COM displacements were strongly and positively associated with VGRF ( ), while the mediolateral COM displacement was negatively associated with knee extension moment ( ). The knee internal-external rotation ROM and anteroposterior and mediolateral COM displacements were positively associated with knee abduction moment ( ). Conclusion. For long-term tai chi exercises, choosing a suitable posture based on an individual exercise level and reasonable control of knee ROM and COM displacement can reduce the risk of knee injury during exercise.

This study aimed to compare the knee and ankle joint load characteristics of high and low Tai Chi postures, focusing on three typical Tai Chi movements: Wild Horse Mane (WHM), Repulse Monkey (RM), and Wave Hand in Cloud (WHC). It further explored how different postures affect lower limb loading in practitioners with varying skill levels to provide optimal guidance for Tai Chi practice. A total of 26 male participants were enrolled, divided into the professional group (PG, n = 13) and the interest group (IG, n = 15). A three‐dimensional (3D) high‐speed motion capture system was employed to record participants’ Tai Chi movements, while a force platform was used concurrently to collect kinematic and dynamic data. For the knee joint, both groups exhibited significantly higher peak moments in the sagittal and coronal planes during the low posture than the high posture across all three movements ( p < 0.05). During WHM, significant differences in peak ankle moments (sagittal and coronal planes) were noted between the two groups. In RM, the IG showed significantly higher peak ankle moments (sagittal and coronal planes) than the PG ( p < 0.05). A significant positive correlation was found between posture/skill level and lower limb joint loading, with the knee joint being most affected. Professional practitioners should strengthen the muscles surrounding the knee and ankle joints to enhance joint protection during high‐intensity practice and prevent chronic sports injuries resulting from long‐term joint fatigue. For amateurs, a gradual transition from high to low postures is recommended to adapt to and enhance joint load‐bearing capacity. Additionally, beginners should prioritize ankle flexibility training to improve ankle stability and lower injury risk.