The biomechanical assessment of the Tai Chi Chuan movement and implication in rehabilitation exercise
On the clinical side, the patients with movement disorders need to do reasonable exercise in rehabilitation. Tai Chi Chuan (TCC) is a type of traditional Chinese martial art and is considered benefiting physical fitness. Many studies have examined the effectiveness of TCC on lower limb biomechanics, balance, and muscle strength either in the healthy or patient conditions; the initial results have shown that TCC is good for some specific patient groups. However, these studies have some limitations such as single-gender and some studies had a small sample size, so the evidence of how TCC is beneficial to physical fitness is still inconclusive. So far, little research has been done on the relationship between joint kinetics of the TCC practitioners and walking gait. This study aimed to investigate whether TCC improves lower limb conditions. Also, the muscle forces during gait will be analysed using computer musculoskeletal models. Methods: Two groups of participants were recruited; 20 from TCC experienced ones and 25 from the Non-Tai Chi Chuan (NTCC) as control with matched age from 42-78 years old. We used the Vicon system to compare the lower limb gait, the force sensor (FS) device to measure lower limb and hand muscle strength, the electromyography (EMG) to measure lower limb muscles activities, the timers to measure two balance tests, and the musculoskeletal model to estimate the lower limb muscle forces. Results: In the gait test, the TCC practitioners could walk faster significantly compared to NTCC. Also, the TCC practitioners had larger range of motion (ROM) in the major joints (hip, knee, and ankle) than NTCC during the stance phase gait. Related to the FS measurements, it is found that the TCC practitioners were stronger than NTCC with significant differences in the knee extensor muscles. On the other hand, it isfound that the NTCC practitioners were stronger xix than TCC with significant differences in the hip extensor, knee flexor, and ankle plantar flexor muscles and there were no significant differences between the two groups in hand muscles forces. Moreover, single-leg stance (SLS) balance in the TCC practitioners has better stability in balance than NTCC with, while the four-step square test (FSST) did not show significant differences between the two groups. In conclusion: the TCC has better stability than NTCC, and also benefits for the knee extensor muscles, but not improve too much for hip extensor, knee flexor, and ankle plantar flexor muscles. So, the TCC could be considered as an effective rehabilitation exercise to improve people's health especially for the elderly.