Abstract
Aim
Examine age-related differences in muscle size and strength of the knee extensors in individuals with cerebral palsy (CP) and individuals with typical development (TD).
Methods
54 individuals with CP (14.5 ± 4.5 years, GMFCS I–V) and 33 individuals with TD (16.2 ± 5.5 years) were included. Relationships between rectus femoris (RF) and vastus lateralis (VL) muscle volume and isokinetic knee extensor strength with age were examined with linear regression and ANCOVA to test age-related differences between groups.
Results
Linear regression for muscle volume with age was statistically significant in TD (VL: r2 = 0.48, RF: r2 = 0.56, p < .05) and those with CP (VL: r = 0.36, RF: r2 = 0.27, p < .05) with no differences in regression slopes between groups (p > .05). Age-related strength differences were observed in TD (r2 = 0.66, p < .001) and those with CP (r2 = 0.096, p = .024), but the slopes were significantly different between CP and TD (p < .001).
Conclusion
Age-related linear differences in muscle volume and strength were observed in both groups. The linear slope of the age-related differences in knee extensor muscle strength and strength-to-body mass ratio were significantly lower in individuals with CP compared to individuals with TD, suggesting that strength is insufficient to keep up with gains in body mass during growth.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Funding
Notes on contributors
Mattie E. Pontiff
Mattie E. Pontiff, PT, PhD is currently a post-doctoral fellow at the University of Colorado Anschutz Medical Campus and the Rocky Mountain Regional VA Medical Center in the Center of Innovation. Dr. Pontiff completed this work during her doctoral training with Dr. Moreau at LSUHSC-New Orleans. Her current work is focused on implementing high-intensity resistance training in medically complex older adults.
Noelle G. Moreau
Noelle G. Moreau, PT, PhD is a Professor at the Louisiana State University Health Sciences Center in New Orleans. Dr. Moreau’s research focuses on the investigation of the neuromuscular mechanisms underlying abnormal muscle function and movement impairments in children with cerebral palsy, using techniques such as ultrasound imaging, dynamometry, and electromyography. Dr. Moreau received her doctoral training in biomechanics with a minor in biostatistics at Louisiana State University and completed a postdoctoral fellowship in movement sciences at Washington University in St. Louis. The overarching goal of Dr. Moreau’s research is the development of effective rehabilitation strategies to address these impairments and improve activity, participation, and quality of life.