BACKGROUND & OBJECTIVE
The proportion of young individuals meeting recommended physical activity guidelines has been decreasing over previous decades. Physical activity in adolescence and early adulthood is important as it can influence physical activity engagement later in life. Subsequently, young individuals who sustain a serious injury, such as an anterior cruciate ligament (ACL) tear, may be vulnerable to being less active in the long-term.
Considering females are more likely to experience worse outcomes following anterior cruciate ligament reconstruction (ACLR), this cross-sectional study aimed to examine the effect of sex and injury on physical activity. It was hypothesized that females who have undergone ACLR would engage in less moderate-to-vigorous physical activity (MVPA) and be less likely to meet recommended physical activity guidelines (150 minutes of MVPA per week) than males who have undergone ACLR, as well as healthy males and females.
Injured participants were recruited if they had a history of primary unilateral or bilateral ACLR within the last 5 years. Healthy participants were included if they did not have any history of a lower extremity injury that required surgery.
All participants completed a series of questionnaires which included the Tegner Activity Scale for self-reported activity level, and the Knee injury and Osteoarthritis Outcome Score (KOOS) for self-reported knee function. The primary outcome was physical activity which was objectively measured using an accelerometer (ActiGraph GT3X). Participants were asked to wear the accelerometer for 7 days. A minimum of 4 days of wear time was considered valid for data analysis. Minutes of MVPA per week and percentage of time spent in MVPA were used as absolute and relative measures of physical activity, respectively.
There were 25 male and 34 female participants who had a previous ACLR with a mean time since surgery of 25.9 months and 32.1 months, respectively. In addition, there were 22 healthy male and 33 healthy female participants. The mean