Author(s): MANDALIDIS, D., CHATZIANTONIOU, M., KAFETZAKIS, I., Institution: NATIONAL AND KAPODISTRIAN UNIVERSITY OF ATHENS, Country: GREECE, Abstract-ID: 2716

INTRODUCTION:
Shoelace ankle braces are commonly used in physically active populations as preventive and supportive interventions for lateral ankle sprains and chronic ankle instability. While these orthoses enhance mechanical stability at the talocrural and subtalar joints, the associated restriction of joint motion may alter lower-extremity biomechanics during locomotion, potentially modifying joint loading patterns and influencing injury risk. The purpose of this study was to investigate the effects of a shoelace ankle brace on spatiotemporal parameters and ground reaction forces during walking and running in healthy adults.
METHODS:
Nineteen physically active male college students (20-30 years of age) participated in this repeated-measures laboratory study. Participants performed barefoot walking (1.4 m·s⁻¹) and running (2.2 m·s⁻¹) trials under two conditions: unbraced and braced, with a shoelace ankle brace applied to the right limb. Spatiotemporal parameters (step length and time, cadence, step width, foot rotation, and phase durations), anteroposterior and mediolateral center of pressure trajectories (APpCOP, MLpCOP), and vertical ground reaction forces (vGRFs) applied to the forefoot, midfoot, and rearfoot were recorded using an instrumented treadmill. Statistical analysis was conducted using two-way repeated-measures ANOVA, including interaction effects. Significance was set at p < 0.05.
RESULTS:
During walking, the braced (right limb) condition significantly increased right-step length (p < 0.001) and step time (p < 0.01), while reducing cadence (p < 0.01) and right foot rotation (p < 0.05). Left stance duration increased (p < 0.01), particularly during midstance (p < 0.05), whereas right swing duration was prolonged (p < 0.01). vGRFs also increased at the forefoot (p < 0.01) and midfoot (p < 0.001) of the braced limb. During running, foot rotation (p < 0.001) decreased on the braced (right) limb, and step width (p < 0.01) increased, while step length, step time, cadence, and phase durations remained unchanged. In the braced limb, vGRFs also decreased at the forefoot (p < 0.05) and increased at the midfoot (p < 0.001) and rearfoot (p < 0.05). APpCOP and MLpCOP trajectories were not significantly affected in either locomotor condition.
CONCLUSION:
The shoelace ankle brace altered walking mechanics by increasing step length and step time while reducing foot rotation and cadence, indicating a slower and more controlled gait pattern. Stance duration and midfoot–forefoot loading increased, suggesting modified plantar load distribution. During running, most spatiotemporal parameters remained unchanged; however, reduced foot rotation and increased step width were observed, accompanied by a shift in vertical forces toward the midfoot and rearfoot. Although these adaptations may enhance frontal-plane stability and mediolateral control, the redistribution of plantar loads may increase localized tissue stress and potential injury risk over time.