Temporal changes in gait parameters and muscle activation during sustained walking in children with spastic cerebral palsy.

OBJECTIVE: Temporal changes in spatiotemporal gait parameters and muscle activation may reflect progressive gait deterioration during prolonged walking in children with spastic cerebral palsy. METHODS: A portable gait analysis system and surface electromyography were used to evaluate gait characteristics during a 3-minute walking protocol in 15 children with SCP and 15 age-matched healthy controls. Participants walked at a self-selected speed on a level surface. Spatiotemporal gait parameters, energy expenditure, and bilateral gastrocnemius and tibialis anterior muscle activation were assessed at predefined time points. Linear mixed-effects models were applied to examine group-by-time interactions while accounting for repeated measurements within participants. RESULTS: Linear mixed-effects model analysis revealed significant Group × Time interactions for stance phase, swing phase, step length, lower-limb forward acceleration, foot clearance angle, and walking velocity (all P < 0.05), indicating divergent temporal trajectories between children with SCP and healthy controls. No significant Group × Time interactions were observed for single-step time, gait cycle duration, or cadence (all P > 0.05). For energy expenditure, a significant Group × Time interaction (P = 0.047) indicated that the SCP group maintained elevated metabolic cost into the third minute while controls exhibited a declining trajectory. Similarly, significant Group × Time interactions were observed for bilateral gastrocnemius (P = 0.002) and tibialis anterior (P = 0.006) normalized root mean square amplitudes, reflecting a greater temporal decline in muscle activation in the SCP group from the second minute onward. CONCLUSION: Children with SCP may exhibit gradual changes in spatial-temporal gait parameters and muscle activation patterns during the later stages of a long walking task. These findings suggest that selected gait and EMG parameters in children with SCP begin to change after approximately 2 min of continuous walking, indicating a potential time window for closer monitoring or structured rest breaks during rehabilitation. Further studies incorporating direct fall-risk assessment and validated fatigue measures are warranted before definitive clinical recommendations can be made.