LAUSR

BACKGROUND Individuals with a spinal cord injury (SCI) report decreased participation in daily and social activities. Self-determination theory (SDT) posits that individuals' need satisfaction and frustration predicts participation in health-related behaviours and this relationship is mediated by their motivation. OBJECTIVES This study explored the role of psychological needs and motivation in relation to participation in daily and social activities among adults with SCI. It was hypothesized that: a) need satisfaction and need frustration were positively associated with autonomous and controlled motivation, respectively, which, positively and negatively predicted participation in daily and social activities; b) autonomous and controlled motivation mediated the need satisfaction/frustration and participation relationship, respectively; and c) need frustration was positively related to amotivation, with no relationship between amotivation and activity participation. METHODS In this cross-sectional study, adults with SCI (N = 131) completed a questionnaire regarding their need satisfaction/frustration, autonomous and controlled motivation, amotivation, and participation in daily and social activities. RESULTS Need satisfaction was positively related to autonomous motivation (β = 0.29, 95%bias-corrected confidence interval (bCI): [0.04, 0.67]) and need frustration to controlled motivation (β = 0.28, 95%bCI: [0.09, 0.55]). Autonomous motivation was positively associated with six participation categories: autonomous indoor, autonomous outdoor, family role, health, social life, and work/education. Autonomous motivation also mediated the relationship between need satisfaction and all six participation categories; whereas, neither controlled motivation nor amotivation mediated the relationship between need frustration and participation. CONCLUSIONS This study found that SDT provides a meaningful framework for understanding participation among adults with SCI.