Synergistic multi-joint kinematic strategies to reduce tripping risks during obstacle-crossing in older long-term Tai-Chi Chuan practitioners

Abstract

IntroductionLosing balance or tripping over obstacles is considered one of the most common causes of falls in the elderly. Tai-Chi Chuan (TCC) has been shown to improve muscle strength, inter-joint coordination and balance control in the elderly. This study aimed to determine whether older long-term TCC practitioners would show multi-joint kinematic strategies that would reduce the risk of tripping during obstacle-crossing compared to peers without TCC experience.MethodsThree-dimensional motions of the pelvis and lower extremities were measured using a motion capture system in fifteen older long-term TCC practitioners (TCC group) and 15 healthy controls without TCC experience during walking and crossing obstacles of three different heights. Crossing angles of the pelvis and lower limbs and toe-obstacle clearances were obtained and analyzed using two-way analyses of variance to study the between-subject (group) and within-subject (height) effects. A multi-link system approach was used to reveal the relationship between joint angular changes and toe-obstacle clearances.ResultsCompared to the controls, the TCC group showed increased leading and trailing toe-obstacle clearances (p < 0.05) with increased pelvic hiking and hip flexion but decreased hip adduction on the swing side and decreased knee flexion on the stance side during leading-limb crossing (p < 0.05), and increased pelvic hiking and anterior tilt but decreased hip adduction on the swing side, and decreased knee flexion on the stance side during trailing limb crossing (p < 0.05). All significant joint angular changes contributed to the increases in the toe-obstacle clearances.ConclusionThe current study identified the kinematic changes of the pelvis and the lower limb joints and revealed a specific synergistic multi-joint kinematic strategy to reduce tripping risks during obstacle-crossing in older long-term TCC practitioners as compared to non-TCC controls. The observed multi-joint kinematic strategies and the associated increases in toe-obstacle clearances appeared to be related to the training characteristics of TCC movements. Long-term TCC practice may be helpful for older people in reducing the risk of tripping and the subsequent loss of balance.

The effects of Tai Chi on standing balance control in older adults may be attributed to the improvement of sensory reweighting and complexity rather than reduced sway velocity or amplitude

“…Therefore, postural sway in both groups was linked with the vestibular and proprioceptive contribution of standing balance, which suggested that older adults with long-term Tai Chi practice may use greater postural sway in standing balance as an exploratory strategy to ensure continuous dynamic inputs from multiple sensory systems (Carpenter et al, 2010 ; Murnaghan et al, 2011 ). In fact, it has been proven that long-term Tai Chi practice can significantly change the control strategy compared to the control group (Huang et al, 2022 ; Shao et al, 2022 ). On the contrary, older adults with Parkinson's disease (PD) exhibited shorter path length compared to older adults without PD during the unipedal stance, which was explained as the patients with PD are unable to use the exploratory strategy (Smart et al, 2023 ).…”

Children with Duchenne muscular dystrophy display specific kinematic strategies during obstacle-crossing

“…Two infrared retroreflective markers on either end of the tube defined the position and height of the obstacle. Thirty-nine infrared retroreflective markers attached to specific anatomical landmarks tracked the motions of all the body segments, namely anterior superior iliac spines, posterior superior iliac spines, greater trochanters, mid-thighs, medial and lateral epicondyles, heads of fibulae, tibial tuberosities, medial and lateral malleoli, navicular tuberosities, fifth metatarsal bases, big toes and heels, and mandibular condylar processes, acromion processes, spinous processes of the seventh cervical vertebra (C7), medial and lateral humeral epicondyles, and ulnar styloids 27 , 28 , 33 . An eight-camera motion analysis system (Vicon MX T-40, OMG, U.K.) measured the three-dimensional marker trajectories at 200 Hz, while the ground reaction forces (GRF) were measured at 2000 Hz using three forceplates (OR6-7, AMTI, U.S.A.) placed on either side of the obstacle in the middle of the walkway.…”