[Biomechanical analysis of ankle-foot complex during a typical Tai Chi movement-Brush Knee and Twist Step].

The purpose of this study is to analyze the biomechanics of ankle cartilage and ligaments during a typical Tai Chi movement-Brush Knee and Twist Step (BKTS). The kinematic and kinetic data were acquired in one experienced male Tai Chi practitioner while performing BKTS and in normal walking. The measured parameters were used as loading and boundary conditions for further finite element analysis. This study showed that the contact stress of the ankle joint during BKTS was generally less than that during walking. However, the maximum tensile force of the anterior talofibular ligament, the calcaneofibular ligament and the posterior talofibular ligament during BKTS was 130 N, 169 N and 89 N, respectively, while it was only 57 N, 119 N and 48 N during walking. Therefore, patients with arthritis of the ankle can properly practice Tai Chi. Practitioners with sprained lateral ligaments of the ankle joint were suggested to properly reduce the ankle movement range during BKTS.

Tai Chi Is Safe and Effective for the Hip Joint: A Biomechanical Perspective.

There is little research related to the biomechanical effects of Tai Chi on the hip joint. This study was aimed to analyze the biomechanical characteristic of a typical Tai Chi movement, Brush Knee and Twist Step. A total of 12 experienced older men voluntarily participated in this study. Each participant was requested to perform standard Brush Knee and Twist Step and normal walking. The scaled-generic musculoskeletal model of each participant was developed. A finite element model of the hip joint and pelvis was established and validated. Data from each trail were input to the model for simulation, and the biomechanics were compared between Brush Knee and Twist Step and walking. Compared with walking, Tai Chi may have better improvement in the range of motion of the hip joint and the coordination of the neuromuscular system under safer condition. It is suitable for patients with hip osteoarthritis and the older adults with severe muscle loss, and clinical studies are required to confirm it further.

Biomechanical analysis of the meniscus and cartilage of the knee during a typical Tai Chi movement-brush-knee and twist-step.

This study aimed to analyze the biomechanical response of the knee cartilage and meniscus to a typical Tai Chi (TC) movement, brush-knee and twist-step (BKTS). Kinematic and kinetic data was recorded while an experienced TC practitioner performed normal walking, jogging and BKTS. The kinetic data were then imported into a validated finite element model of the knee joint to examine the biomechanical response of the articular cartilage and meniscus. Compared with walking and jogging, the BKTS movement showed a greater increase in the range of motion (ROM) of the knee. The ROM in the sagittal plane was 56° (walking), 38° (jogging) and 93° (BKTS). In coronal plane, the knee ROM was 8° (walking), 11° (jogging) and 28° (BKTS). And in horizontal plane the ROM was 17° (walking), 15° (jogging) and 29° (BKTS). The finite element simulation demonstrated that the pressure contact stress is much more concentrated during walking and jogging than BKTS, which is consistent with the lower peak contact stresses recorded on the cartilage and meniscus. In conclusion, the TC movement produced a gentler stress state on the meniscus and cartilage, while also requiring a greater knee ROM. Practicing TC may have a lower risk of knee joint injury compared to walking and jogging.