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

BACKGROUND: 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. OBJECTIVE/HYPOTHESIS: 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). METHODS: 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. RESULTS: 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 ±â€¯11.49 MET-hrs/day) than those with moderate disabilities (M = 11.27 ±â€¯9.3 MET-hrs/day) and severe disabilities (M = 13.43 ±â€¯14.74 MET-hrs/day). CONCLUSIONS: 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.

Longitudinal changes in psychosocial constructs and physical activity among adults with physical disabilities.

BACKGROUND: Given the importance of physical activity (PA) and the low activity levels among adults with physical disabilities, it is important to understand how temporal changes in psychosocial constructs affect PA changes over time. OBJECTIVE/HYPOTHESIS: Examine if changes in the transtheoretical model (TTM) constructs affected changes in PA levels over time. METHODS: One hundred thirty-two adults with physical disabilities, such as multiple sclerosis and spinal cord injuries, completed a web-based survey once every 4 months, for a total of 3 time points, to assess the TTM constructs and PA. Six latent growth curve analyses were conducted using Mplus(5) to examine if longitudinal changes in the TTM constructs affected temporal changes in PA levels. RESULTS: All six hypothesized models fit the sample data well (e.g., χ(2) = NS; RMSEA = <.001-.06). In a descending order of significance, the best predictors of the initial levels of PA were the stages of change, the behavioral processes of change, the cognitive processes of change, self-efficacy, and perceived pros. The meaningful predictors of PA changes over time were the initial levels and the slopes of the cognitive processes of change, perceived pros, and the behavioral processes of change. Although the slopes of the stages of change and perceived cons did not have a statistically significant effect on PA changes, their effects approached a medium size (.33 and .38, respectively). CONCLUSIONS: In order to reassure the maintenance of an exercise program, interventionists need to first emphasize cognitive, motivational strategies (cognitive processes of change), such as the importance of PA and positive thoughts about exercise participation as well as exercise benefits (pros) before they implement behavioral strategies (behavioral processes of change), such as social support, goal setting, and self-rewarding.

Psychosocial predictors of physical activity and health-related quality of life among adults with physical disabilities: an integrative framework.

BACKGROUND: People with disabilities report lower physical activity (PA) and health-related quality of life (HRQOL) levels than people without disabilities. Therefore, it is important to identify factors that motivate individuals with disabilities to be physically active and thus increase their HRQOL. OBJECTIVES: The purpose of the study was to prospectively explore the effects of past theory of planned behavior (TPB) constructs on future (6-month) HRQOL (physical and mental health) through past stages of change (SOC) and future (6-month) PA among adults with physical disabilities. Two models were tested whereby the SOC and PA served as the mediators between the TPB constructs, physical health (PH-Model), and mental health (MH-Model). It was hypothesized that both models would fit the sample data. METHODS: Participants were 141 adults with physical disabilities (mean age = 46.04, females = 70.9%). The online survey was completed at two different time periods. First, the TPB constructs and SOC were assessed using self-report standardized questionnaires. Six months later, participants completed standardized self-report scales about their PA and HRQOL levels. Using LISREL 8, two path analyses were conducted to examine the two study models (PH-Model and MH-Model). RESULTS: Based on the two path analyses, attitude had the highest effect on SOC followed by perceived behavioral control within both well-fit models. The PH-Model explained more variance in PA (26%) and physical health (55%) than the MH-Model. CONCLUSIONS: Health promoters should reinforce both positive intentions and behavioral experiences to increase PA and HRQOL among adults with physical disabilities.

Physical activity beliefs and behaviour of adults with physical disabilities.

PURPOSE: The purpose of this study was to elicit the physical activity (PA) beliefs from adults with physical disabilities; and second, to examine their self-reported PA participation. METHOD: Participants were 223 adults (M age = 45.4 years, SD = 10.8), with self-reported physical disabilities who completed a web-based survey. Six open-ended questions were used to assess PA beliefs and the PA Scale for Individuals with Physical Disabilities measured self-reported PA. RESULTS: A qualitative analysis showed that the most accessible behavioural advantages are that PA improves emotional functioning and assists with weight management. The most accessible behavioural disadvantages are that PA causes pain or soreness and consumes time. The most accessible normative influences that approve of PA are family, friends, and healthcare professionals. The most accessible control beliefs obstructing PA are disability and associated symptoms, and a lack of access to adequate facilities, equipment, or programs. The most accessible control beliefs that facilitate PA are access to adequate facilities, equipment, or programs, and support or assistance. Finally, the average total PA score was 20.5 metabolic equivalent (METS)-hours/day (SD = 16.8). CONCLUSIONS: Adults with physical disabilities possess unique PA beliefs that can be used to design health promotion interventions to increase PA participation.

The mediating role of intention and stages of change in physical activity among adults with physical disabilities: an integrative framework.

The study's purpose was to identify the mediating role of intention and the stages of change (SOC) in physical activity (PA) over a 6-month period using two models (theory of planned behavior [TPB] and TPB/SOC). Participants were 143 adults with physical disabilities (70.68% response rate; M age = 46.03). The TPB constructs, SOC (time 1), and PA (time 2) were assessed using standardized self-report questionnaires. Based on path analyses, attitude had the highest effect on intention and SOC followed by perceived behavioral control within both well-fit models. The variance in PA explained by the first (TPB) and second (TPB/SOC) models was 16% and 28% respectively. In the just identified model of TPB/SOC, the direct effect of SOC on physical activity remained strong (gamma(soc.pa) = .45) and SOC approached full mediation through attitude. Health promotion interventions need to include both intention and behavior elements (SOC) reinforcing increased PA value and barrier elimination.

MRI-derived body segment parameters of children differ from age-based estimates derived using photogrammetry.

Body segment parameters are required when researching joint kinetics using inverse dynamics models. However, the only regression equations for estimating pediatric body segment parameters across a wide age range were developed, using photogrammetry, based on 12 boys and have not been validated to date (Jensen, R.K., 1986. Body segment mass, radius and radius of gyration proportions of children. Journal of Biomechanics 19, 359-368). To assess whether these equations could validly be applied to girls, we asked whether body segment parameters estimated by the equations differ from parameters measured using a validated magnetic resonance imaging (MRI) method. If so, do the differences cause significant differences in joint kinetics during normal gait? Body segment parameters were estimated from axial MRIs of the left thigh and shank of 10 healthy girls (9.6 +/- 0.9 years) and compared to those from Jensen's equations. Kinematics and kinetics were collected for 10 walking trials. Extrema in hip and knee moments and powers were compared between the two sets of body segment parameters. With the exception of the shank mass center and radius of gyration, body segment parameters measured using MRI were significantly different from those estimated using regression equations. These systematic differences in body segment parameters resulted in significant differences in sagittal-plane joint moments and powers during gait. Nevertheless, it is doubtful that even the greatest differences in kinetics are practically meaningful (0.3% BW x HT and 0.7% BW x HT/s for moments and power at the hip, respectively). Therefore, body segment parameters estimated using Jensen's regression equations are a suitable substitute for more detailed anatomical imaging of 8-10-year-old girls when quantifying joint kinetics during gait.