Walking-induced muscle fatigue impairs postural control in adolescents with unilateral spastic cerebral palsy

Background: Fatigue is likely to be an important limiting factor in adolescents with spastic cerebral palsy (CP). Aims: To determine the effects of walking-induced fatigue on postural control adjustments in adolescents with unilateral CP and their typically developing (TD) peers. Methods: Ten adolescents with CP (14.2 ± 1.7 yr) and 10 age-, weight- and height-matched TD adolescents (14.1 ± 1.9 yr) walked for 15 min on a treadmill at their preferred walking speed. Before and after this task, voluntary strength capacity of knee extensors (MVC) and postural control were evaluated in 3 conditions: eyes open (EO), eyes closed (EC) and with dual cognitive task (EODT). Results: After walking, MVC decreased significantly in CP (-11%, P < 0.05) but not in TD. The CoP area was only significantly increased in CP (90%, 34% and 60% for EO, EC and EODT conditions, respectively). The CoP length was significantly increased in the EO condition in CP and TD (20% and 21%) and was significantly increased in the EODT condition by 18% in CP only. Conclusions: Unlike TD adolescents, treadmill walking for 15 min at their preferred speed lead to significant knee extensor strength losses and impairments in postural control in adolescents with unilateral spastic CP.