Improving Reaction Time, Static Balance Control, and Gait in Adults with Autism Spectrum Disorder and an Intellectual Disability: An Exercise Intervention Study

Background: Recent research has documented differences in motor skill abilities in individuals with autism spectrum disorder (ASD), in comparison to typically developing individuals.  In particular, differences in gait, static balance control, and manual motor reaction time (RT) have all been identified.  Given the importance of these motor skills for independence, safety, and quality of life, investigation of activities that promote the development of these skills in this population is warranted.  Participation in exercise and sports/games may have implications for individuals with ASD beyond general health and fitness benefits, such as promoting improvements in coordination and motor skills.  To date, little research exists regarding the benefits of exercise for motor skills development in adults with ASD.

Objectives: To assess the impact of a 12-week adapted physical exercise (APEX) program on gait, static balance control, and simple manual RT in adults with ASD and an intellectual disability (ID).

Methods: Fourteen adults diagnosed with ASD and an ID participated in a 12-week APEX program (age range = 18-62 years; 2 females; IQ scores from previous clinical assessment = 20-70).  Each participant was paired with a trainer to complete two 90-minute exercise sessions per week.  The sessions included a warm-up, 20 minutes of cardiovascular exercise (cycling on a stationary bike), 20 minutes of strength training (machines and free weights), sports and games, and a cool-down.  Fitness and motor skills testing was conducted pre-, mid-, and post-program so that any observed changes could be compared to the participants’ own pre-program measurements.  Each motor skills test session included three trials of walking across an instrumented walkway at a natural walking speed (gait); four, 20-second trials (two with eyes open, two with eyes closed) of quiet standing on a force platform (static balance); and fifteen trials per hand of a computerized test of simple manual RT. 

Results: Mean RT (right and left hands collapsed) significantly decreased from pre-program (570 ± 78 ms) to mid-program (432 ± 78 ms, p = 0.04) and to post-program (385 ± 79 ms, p= 0.008).  There were no significant changes in any of the static balance variables [anterior-posterior and medial-lateral RMS displacements and sway areas (RMS and range) of the center of pressure (COP): p > 0.05]; nor in any of the gait variables (velocity, step length, heel-to-heel base of support, swing and stance phases as percent of gait cycle, toe in/out angles: p> 0.05).  

Conclusions: The APEX program provided a combination of cardiovascular and strength training, along with a sports/games component.  The improvement in RT, but not in gait or static balance control, may be related to the APEX program format.  Many activities within the sports/games component would have challenged participants’ RT (e.g. catch, badminton), and likely elicited the participants’ improvement in this domain.  However, none of the exercises included in the APEX program specifically focused on improving gait or balance.  Future exercise programming should include components that specifically target these skills in order to elicit improvement.