Self-Determination for Physical Activity Among Adults With Physical Disabilities

Background/Purpose: Although physical activity participation has numerous psychosocial and physiological benefits, only 18% of adults with disabilities participate regularly in physical activity of moderate or higher intensity compared with 33% of adults without disabilities (Healthy People, 2020). One of the goals of Healthy People 2020 is to increase physical activity participation among adults with disabilities (Healthy People, 2020). One way to achieve this goal is to rely on motivational theories of physical activity promotion, such as the self-determination (SD) theory (Deci & Ryan, 1985). Based on the SD theory, motivational orientations (e.g., intrinsic motivation) are stipulated to mediate the relation between certain psychological needs (e.g., exercise competence) and exercise participation. To date, this theory has not been used among adults with physical disabilities. Therefore, the purpose of this study was to test the SD theory among adults with physical disabilities in order to determine the most important, psychosocial predictors of exercise participation.

Method: There were 126 participants (M age = 54.36 ± 10.27 years, females = 70%, Caucasian = 93%) and most of them had multiple sclerosis (46%) and spinal cord injury (39%). They completed online self-report standardized scales, which measured psychological needs (autonomy, competence, relatedness), motivation continuum (external regulation, introjected regulation, identified regulation, and intrinsic motivation), and physical activity levels.

Analysis/Results: Based on structural equation modeling, the SD theory fit the sample data well (e.g., χ² = 28.41, p = .08; RMSEA = .06, GFI = .95). The psychological needs had a large effect on motivation (.96) and motivation had a medium effect on physical activity (.40). In a descending order of significance, perceived competence (.79), relatedness (.63), and autonomy (.49) were the most important indicators of the latent variable “psychological needs.” Similarly, intrinsic motivation (.87), identified regulation (.85), and introjected regulation (.53) were the most important indicators of the latent variable “motivation” for exercise participation. The variance explained in motivation and physical activity was 89% and 16%, respectively.

Conclusions: This is the first study to examine the usage of the SD theory for exercise promotion among adults with physical disabilities. In their physical activity motivational programs, health promoters should reinforce positive exercise experiences (competence), social support (relatedness), personal exercise choices (autonomy), enjoyable activities (intrinsic motivation), and the value of exercise (identified regulation). Although social pressure to be active can be important to this population, it may be necessary to be downplayed for long-term exercise participation.