Changes in Muscle Strength, Static Balance and Dynamic Plantar Pressures in Autism Spectrum Disorder

Background: Individuals with autism spectrum disorder (ASD) show affected sensorimotor skills that impair postural control and static balance, both necessary components of standing and walking without risk of fall and injury. Muscle strength, body composition and reaction time are known to effect injury risk from falls.

Objectives: To examine the extent of alterations in static balance, gait alterations within individuals with ASD.

Methods: Forty-eight subjects (14.3 ± 4.3 years) participated in this study. Height (62.8 ± 6.1 inches), weight (133.5 ± 50.9 pounds), body mass index (23.0 ± 6.4), fat deposition (25.9 ± 9.8 % body fat), grip strength (11.4 ± 6.4 kg), upper body strength, standing balance and reaction time were measured. Correlations with Childhood Autism Rating Scale (CARS-2) and other incidence reports were also investigated. Plantar forces, pressures and oscillations during walking were also analyzed and compared to a control group of non-ASD subjects.

Results: Compared to normative values, arch index was decreased (pes cavus) in subjects with ASD. Plantar force distribution surface area distribution during walking was significantly different in individuals with ASD. During static balance assessment, center of pressure distances and speed of deviations were significantly greater in subjects with ASD.

Conclusions: Overall, these findings are consistent with clinical observations that abnormalities of movement performance and cognitive performance are an associated feature of ASD in children and young adults. These abnormalities may contribute to the increased rates of injuries that individuals with ASD experience. Implications for intervention to potentially mitigate these deficiencies are discussed.