Pain as a barrier to physical activity in severe obesity and the alter-g anti-gravity treadmill as a potential therapeutic tool
Obesity is highly prevalent, and more than 36.5% of American adults have obesity. Common barriers to physical activity in people with obesity are pain and low enjoyment, and both may contribute to low levels of activity. The use of the Alter-G Anti-Gravity Treadmill as a therapeutic tool to overcome these barriers is a new area explored in this study. Specific aims explored in this study were to determine if: Aim 1 - pain was associated with physical functioning in obesity, Aim 2 - exercise barriers were reduced by using the unweighting function of the Alter-G Anti-Gravity Treadmill, and Aim 3 - energy expenditure of moderate intensity exercise sessions with self-selected duration was similar in weighted and unweighted groups. Healthy adults (20- 55 years) with obesity (≥30 BMI) were recruited for this study. Participants were randomized into two groups with the control group exercising at 100% body weight and the experimental group using the unweighting function with self-selection of body weight. This project was an analysis of baseline data from a longer randomized trial of a 12 week walking program. Measurements taken during the baseline visit include physical functioning test (6-minute walk test and Timed Up and Go) and questionnaires (Short-Form McGill Pain Assessment, Physical Activity Enjoyment Scale (PACES), and History of Joint Pain). After baseline measurements, energy expenditure during exercise sessions (calculated by the Alter-G`s Stride Smart system), Physical Activity Enjoyment Scale (after experiencing the Alter-G Anti-Gravity Treadmill for three workouts), and Subjective Pain during exercise sessions (provided by the Alter-G`s Stride Smart system) were measured. There were sixteen (9 female, 7 male) participants (age M = 33.06, SD =10.99, weight (kg) M = 107.51, SD = 13.30, BMI (kg/m²) M = 37.94, SD = 5.20) that participated in the study. They were randomized into two groups (control n = 10, experimental n = 6). There was no detectable association between pain and physical functioning. Subjective pain was not statistically different between the two groups (p = .156), and change in PACES scores were not statistically different between groups (p = .947). However the experimental group did have a statistically significant increase in PACES scores from the baseline measurement (M = 82.40, SD = 14.63) to the measurement taking after the 3rd visit (M =92.40, SD = 10.71) (p = .043). There was no difference in energy expenditure between groups. The exercise sessions were broken down into average speed, incline, and duration. The average speed (p = .280) and incline (p = .758) was not statistically different between groups, but the duration was significantly higher in the experimental (M = 45.64, SD = 2.43) group compared to the control (M = 37.52, SD = 1.81) group, (p = .020). This study demonstrated that a walking protocol using the unweighting feature of Alter-G Anti-Gravity Treadmill was associated with a significant increase in PACES score, and that using the unweighting feature of the Alter-G Anti-Gravity Treadmill can cause the duration during exercise be higher, leading to similar energy expenditure compared to exercising at 100% body weight.