Motion Analysis During Balance Training Using a Dual-Belt Treadmill

This study aimed to analyze motion during DBT training in older adults and clarify the relationships between balance ability and spatiotemporal parameters.

A DBT session of four three-minute sets was conducted with 45 community-dwelling older adults (mean age: 71.0 ± 5.1 years). Performance during the first and last minutes of each set was measured using markerless motion capture with a depth camera (MA-1500, ANIMA Inc., Japan). Movement directions associated with button pressing were classified as forward and backward within the same lane, and lateral, oblique forward, and oblique backward between lanes. Changes in the center of mass (COM) trajectory from the first to the fourth set for each movement direction were examined. Performance characteristics in the fourth set were also examined in relation to the Community Balance and Mobility Scale (CB&M), maximum COM speed in the direction of movement, and maximum horizontal distance between the COM and the ankle joint (COM-ankle distance).

After one session, the time required, total anterior-posterior COM trajectory length, and jerk index significantly decreased across all directions. In the fourth set, maximum forward COM-ankle distance during forward movement (r = 0.30) was significantly associated with the CB&M. During lateral movement, significant associations with CB&M were observed for maximum lateral speed (r = 0.37), backward COM-ankle distance (r = 0.32), and lateral COM-ankle distance of the leading and trailing limbs (r = 0.31, 0.31). During oblique forward movement, significant associations with CB&M were observed for maximum forward and lateral speeds (r = 0.35, 0.30), backward COM-ankle distance (r = 0.32), and lateral COM-ankle distance of the trailing limb (r = 0.40). During oblique backward movement, significant associations with CB&M were observed for maximum lateral speed (r = 0.34) and lateral COM-ankle distance for the leading and trailing limbs (r = 0.33, 0.34).

DBT improved performance even after one session, enhancing the stability and efficiency of the COM trajectory. During lane-to-lane transitions, lateral movement speed and COM-ankle distances are critical parameters for assessing balance ability.

DBT is a unique training method involving multi-directional movements on a dual-belt treadmill, suggesting that focusing on lateral movement strategies can improve balance.