Psychometric properties and analysis of the physical activity Social Influence Scale for adults with traumatic brain injuries.

The study consisted of (a) assessing the validity and reliability of the Social Influence Scale (SIS) for adults with brain injuries and (b) examining the kinds and sources of social influence and demographic variables that affect participants' physical activity behaviors. Three confirmatory factor analyses, intraclass correlations, and a repeated measures MANOVA were completed on responses from 402 adults with brain injuries. Results provide evidence of the validity and reliability of the SIS, and post hoc analyses revealed that participants reported receiving different types of social influence from family, friends, and caregivers. Findings have implications for specialists and suggestions are provided on ways to enhance the physical activity participation of adults with brain injuries.