title: Perceived personal importance of exercise and fears of re-injury: a longitudinal study of psychological factors related to activity after anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  Psychological perceptions are increasingly being recognized as important to recovery and rehabilitation post-surgery. This research longitudinally examined perceptions of the personal importance of exercise and fears of re-injury over a three-year period post anterior cruciate ligament (ACL) reconstruction. Stability and change in psychological perceptions was examined, as well as the association of perceptions with time spent in different types of physical activity, including walking, household activities, and lower and higher risk for knee injury activities.
  
  
  METHODS
  Participants were athletes, 18-40 years old, who underwent ACL reconstruction for first-time ACL injuries. They were recruited from a tertiary care centre in Toronto, Canada. Participants completed interviewer-administered questionnaires pre-surgery and at years one, two and three, postoperatively. Questions assessed demographics, pain, functional limitations, perceived personal importance of exercise, fear of re-injury and physical activities (i.e., walking; household activities; lower risk for knee injury activities; higher risk for knee injury activities). Analyses included fixed-effect longitudinal modeling to examine the association of a fear of re-injury and perceived personal importance of exercise and changes in these perceptions with the total hours spent in the different categories of physical activities, controlling for other factors.
  
  
  RESULTS
  Baseline participants were 77 men and 44 women (mean age = 27.6 years; SD = 6.2). At year three, 78.5% of participants remained in the study with complete data. Fears of re-injury decreased over time while personal importance of exercise remained relatively stable. Time spent in walking and household activities did not significantly change with ACL injury or surgery. Time spent in lower and higher risk of knee injury physical activity did not return to pre-injury levels at three years, post-surgery. Greater time spent in higher risk of knee injury activities was predicted by decreases in fears of re-injury and by greater personal importance of exercise.
  
  
  CONCLUSIONS
  This study highlights not only fears of re-injury, which has been documented in previous studies, but also the perceived personal importance of exercise in predicting activity levels following ACL reconstructive surgery. The findings can help in developing interventions to aid individuals make decisions about physical activities post knee injury and surgery.
authors.affiliation: Institute for Work and Health; Division of Health Care & Outcomes Research, Arthritis Community Research and Evaluation Unit, Toronto Western Research Institute; Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.
authors.forename: Monique Am
authors.initials: MA
authors.lastname: Gignac
authors.affiliation: Arthritis Community Research and Evaluation Unit, Toronto Western Research Institute, Toronto, Canada.
authors.forename: Xingshan
authors.initials: X
authors.lastname: Cao
authors.affiliation: Postdoctoral Fellow, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Canada.
authors.forename: Subha
authors.initials: S
authors.lastname: Ramanathan
authors.affiliation: Joint Department of Medical Imaging, Faculty of Medicine, University Health Network, Mount Sinai Hospital, Women's College Hospital, University of Toronto, Toronto, Canada.
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: White
authors.affiliation: Ontario Veterinary College, University of Guelph, Guelph, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Hurtig
authors.affiliation: Division of Orthopaedic Surgery, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Monica
authors.initials: M
authors.lastname: Kunz
authors.affiliation: Division of Orthopaedic Surgery, Faculty of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Marks
keywords: ACL injuries; Anterior cruciate ligament reconstruction; Exercise identity; Fear of re-injury; Osteoarthritis; Perceived importance of exercise; Physical activity; Psychological factors; Sports injuries