Specific features that characterize the tai chi protocol include weight shifting and ankle sway, which move center of gravity toward the limits of stability ⁽²⁸⁾. Alternating narrow and wide stances continually change the base of support, increase support-leg standing and trailing-leg swing time, and encourage torso rotation with an upright posture. Forward heel-to-toe and backward toe-to-heel steps strengthen dorsiflexion and plantar flexion, respectively.

Regular tai chi practice also incorporates semi-squatting positions and abdominal breathing producing lower extremity muscle co-contractions that affect neuromuscular coordination, gait, and postural control, as well as bone mineral density by producing stress changes in the lumbar spine and femur ^(61) (63). Improved mobility is related to increased flexibility and balance ⁽⁶⁾, and are also the mechanisms by which tai chi practice helps prevent falls ⁽⁴¹⁾.

In patients with Parkinson’s disease, fMRI studies associated improved balance score with visual network changes, the reduced connections of which have been shown in PD patients with frozen gait ⁽⁶²⁾. Tai chi particularly appears to alleviate bradykinetic movements by improving gait characteristics such as maximum excursion, while reducing deviation in movement and markedly increasing gait velocity and stride length ⁽²⁸⁾. Reduced markers of inflammation and improvements in amino acid, energy, and neurotransmitter metabolism were also attributed to long-term effects on Parkinson’s severity and balance scores ⁽⁶²⁾.

Other studies evaluating biomarker changes suggest the physical aspects of tai chi mediate reductions in both decreased fat mass and IL-2 levels along with increased fat-free mass and IL-6, while the meditative component may also contribute to anti-inflammatory effects ⁽⁴²⁾. Declining pro-inflammatory cytokine IL-2 levels further result in increased bone formation and metabolism levels ⁽⁴³⁾. Other anti-inflammatory effects include increased superoxide dismutase activity with reduced IL-1β ⁽⁴⁴⁾.