Do temporal scores of motivational constructs correspond with physical activity levels?

Adults with physical disabilities typically engage in low levels of physical activity (PA), thus a better understanding of how motivational factors and behavior vary over time and in relation to disability type and severity is needed.

To examine temporal changes in theory of planned behavior (TPB) constructs and PA by disability type (multiple sclerosis vs. spinal cord injury) and severity (mild, moderate, and severe).

Participants were 77 adults with physical disabilities who completed a web-based survey that assessed the TPB constructs and PA participation. The survey was completed once every four months for a total of three time points. Two-way repeated measures ANOVAs were used to examine if the TPB constructs and PA changed over time and in relation to disability type and severity.

There was only one significant between-subjects effect for PA by disability severity, F (2, 68) = 5.94, p = .004, η² = 15%. People with mild disabilities exhibited higher mean PA participation over the three time periods (M = 21.06 ± 11.49 MET-hrs/day) than those with moderate disabilities (M = 11.27 ± 9.3 MET-hrs/day) and severe disabilities (M = 13.43 ± 14.74 MET-hrs/day).

Although participants possessed positive PA motivational factors that remained stable over time, their PA participation was low and differed as a function of disability severity. Therefore, PA interventions should be tailored such that individuals with severe disabilities receive the greatest amount of exercise prescription consultations and supervision compared to those with more moderate and mild disabilities.