Cross-lagged assessment between indices of leisure time physical activity and domains of quality of life after electrical stimulation training in persons with spinal cord injury: An exploratory trial

Abstract: BACKGROUND: An existing association was noted between leisure time physical activity (LTPA) and quality of life (QOL) after spinal cord injury (SCI). Furthermore, electrical stimulation exercise program has been shown to improve domains of QOL. However, the relative causality between indices of LTPA and domains of QOL are not well studied before or after a regimen of electrical stimulation program in persons with SCI. OBJECTIVE: To examine the relationships between levels of weekly leisure-time physical activity (LTPA) and quality of life (QOL) domains before and after 24 weeks of an electrical stimulation exercise program in persons with spinal cord injury (SCI). DESIGN: Longitudinal exploratory trial as part of a randomized clinical trial. SETTING: Veterans Affairs medical center and SCI center. PARTICIPANTS: A convenience sample of 31 participants with chronic SCI were randomized into two groups of 15 and 16, respectively. INTERVENTIONS: The first group underwent twice weekly sessions of lower extremity neuromuscular electrical stimulation-resistance training (NMES-RT) for 12 weeks and a subsequent 12 weeks of twice-per-week functional electrical stimulation lower extremity cycling. The second group underwent an identical regimen with the exception that NMES-RT was substituted for passive movement training. MAIN OUTCOME MEASURES: Outcome measures included the QOL Short Form and the LTPA Questionnaire that were conducted at baseline (T1); post intervention one (T2) and post intervention two (T3). A series of cross-lagged panel models was run with Amos Version 29.0 to test relative directional effects of LTPA and QOL on each other over time. RESULTS: After combining both groups, psychological and social QOL tended to have a stronger directional effect on LTPA, but after the intervention the directional effect reversed. Although LTPA had no directional effect on physical health QOL, it became more dominant in the psychological health domain from T2 to T3. The cross-lagged effect from LTPA to psychological health QOL was either larger or demonstrated a more positive effect relative to the cross-lagged effect from psychological health QOL to LTPA. CONCLUSIONS: Twenty-four weeks of an electrical stimulation program did not directly enhance indices of LTPA after SCI. However, suggested improvements in psychological and social domains may be due in part to LTPA following an electrical stimulation exercise program.