Biomechanical analysis of gait termination within set stopping distance: A pilot study

Under conditions of restricted stopping distances, gait termination comprises a critical motor task, wherein precise balance control and coordination are prerequisites to prevent falls or collisions. Despite several studies on gait termination, the specific biomechanical effects during unplanned gait termination remain underexplored. To provide insights into adaptive motor-control strategies under challenging conditions, such as abrupt stopping, we ascertained trends in biomechanical adaptations during gait termination within restricted distances in healthy young adults. This cross-sectional study included 12 healthy young adults. Participants were instructed to follow a guiding line to control walking speed (at 100 % and 125 % of comfortable speed) and stopped in front of an emerging red line at 1.75 × or 1.5 × the leg length (measured from the anterior superior iliac spine to the medial malleolus) from the pelvis marker. Three-dimensional motion analysis and force-plate data were used to evaluate key biomechanical parameters. Two-way repeated-measures analysis of variance, with velocity and distance as variables, was performed for each parameter. Among participants [age, mean (SD): 22.4 (3.1) years], short, compared to long, stopping distances generated smaller anteroposterior (AP) maximum forces (propulsion; P < 0.001) and reduced the event time at the first stepping from the emerging red line (P = 0.02) as well as the AP minimum force (braking; P < 0.001) and time interval (P = 0.02) between toe-off and first stepping. Thus, biomechanical strategies employed by healthy young adults in adaptation to restricted stopping distances facilitate a better understanding of motor control and balance under constrained gait conditions.