Gait patterns observed during obstacle walking in adults with mild intellectual disability

To compare three-dimensional gait kinematics, pressure-platform-derived variables, and intellectual disability during level walking and obstacle negotiation.

Twenty participants were enrolled (mild intellectual disability, n = 10; control, n = 10). Participants walked barefoot at a self-selected speed during level walking and obstacle crossing over three heights (2.5, 5.2, and 15.2 cm). Three-dimensional kinematics were captured using inertial measurement units. During level walking, pressure-platform-derived variables, including body-weight-normalized force-related values and peak plantar pressure, were obtained using a pressure platform. Surface EMG activity of the rectus femoris, biceps femoris, tibialis anterior, and medial gastrocnemius was recorded during obstacle walking.

During level walking, adults with mild intellectual disability showed greater hip and knee flexion during early stance phase than controls (p < 0.05). During obstacle negotiation, leading-limb responses primarily reflected obstacle-height effects. In the trailing limb, significant obstacle-height effects were observed for hip flexion, knee flexion, ankle dorsiflexion, ankle inversion, rectus femoris, biceps femoris, and tibialis anterior activity. Significant group-related effects were observed for trailing-limb ankle dorsiflexion and tibialis anterior activity, indicating different ankle-control strategies across obstacle heights between groups.

Adults with mild intellectual disability demonstrate altered gait kinematics and reduced adaptability during obstacle negotiation, particularly in trailing-limb ankle control. These findings support rehabilitation approaches that progressively challenge gait control under commonly encountered environmental constraints to enhance movement regulation during walking.