Online control ability affects precision fitting performances of long-term Tai Chi practitioners in older adults

Age-related decline in goal-directed behavior could be risky for older adults to maintain daily activities. Our previous studies have shown that long-term Tai Chi (TC) practice could improve motor performance and postural control during goal-directed tasks. However, there was a paucity of studies examining TC's effects on online control of goal-directed action.

Do long-term TC practitioners have different kinematic characteristics in online control of goal-directed behavior compared to our control groups during precision fitting tasks?

36 older adults were recruited for sedentary (SE), brisk walking (BW), and TC groups based on their exercise habits. Participants were required to fit a block (90 × 90 mm) through two different openings (130 × 130 mm and 100 × 100 mm) at two different distances (arm's length or 130 % of arm's length). Hand, trunk, and center of pressure (CoP) data were collected and analyzed, where velocities and timing variables were used to evaluate the manual motor control.

We observed that: (1) TC group used significantly less time of completion in all three phases than SE and BW groups, especially in the ADJ phase when condition with more task constraints; (2) TC group demonstrated faster average hand velocity in all three phases than SE and BW groups; (3) TC group had a faster average trunk velocity than SE and BW groups and faster average CoP velocity than the BW group in the ADJ phase.

The long-term TC practitioners might exhibit better online control ability in the precision fitting task than the SE and BW groups, leading to more smooth and effortless goal-directed movement executions. Therefore, the long-term TC practice could be an effective intervention for maintaining precision manual motor control among older adults.