CrossFit® to improve gross motor function and gait in adolescents and young adults with unilateral cerebral palsy: a pilot study

Cerebral palsy (CP) is a childhood disability which affects the development of movement and posture, impairs muscle function and muscle strength, and can furthermore negatively impact gait. Recent data shows that not only strength, but also bouts of anaerobic exercise in patients with CP might help to transfer muscle strength into functional capacity (1). This pilot study examined the feasibility and effects of a functional high-intensity exercise intervention (CrossFit®) performed in a group-setting with unilateral CP patients on indicators of daily functionality, including gait. 9 adolescents with unilateral CP (7 males, 2 females, mean age: 16.9 (SD 3.48); GMFCS Level: I-II) participated in the study. The intervention consisted of two weekly supervised training sessions over 12 weeks, which contained progressive resistance training performed with free weights as well as high-intensity aerobic and anaerobic workouts performed through functional movement patterns which were adapted to individual ability and capacity. A 3D-gait analysis, the six-minute walking-test (6MWT), a clinical exam and the Gross Motor Function Measure-66 (GMFM-66) (2) were performed before and after the intervention. Mean differences were calculated with paired t-tests and corresponding 95% confidence intervals. The exercise intervention was not accompanied by any adverse events except light muscle soreness. We measured a significant increase in the GMFM 66 (p = 0.031, mean difference = 2.19 (CI 0.71-3.67)). Furthermore, a non-significant increase in the distance of the 6 MWT (p = 0.09, mean difference = 29.8 m (CI -5.8-65.5)) and the propulsion ratio (p = 0.067, mean difference 5.4% (CI 0.5-11.4%)) of the affected leg was found. No statistically significant changes were found for Gait Profile Score (GPS) (3), spatiotemporal parameters or clinical exam (ankle range of motion, popliteal angle). This pilot study shows that a high-intensity functional training with free weights (CrossFit®) in adolescents with unilateral CP is a safe training method that might effectively improve gross motor function, endurance, and asymmetry in gait. Therefore, the intervention seems to show a transfer into non-task-specific movements of daily life. Based on this pilot study, studies with bigger patient samples and control groups may be performed to detail the effect of high-intensity functional training. Furthermore, this pilot study raises the question to explore the possibilities of more functional tests to measure daily life function by for example using wearable inertial measurement units (IMU).