Accelerometer-assessed physical activity patterns during the first two years after a non-surgically treated ACL injury

Objectives: To describe physical activity patterns and analyze changes during the first two years after a non-surgically treated ACL injury, and to assess correlations between accelerometer-assessed physical activity and self-reported knee function and knee-related quality of life.Design: Prospective cohort study.Participants: 128 patients (61 females, 25.2 +/- 7.1 years) with acute ACL injuryMain outcome measures: Physical activity patterns were measured with accelerometry. Self-reported knee function was assessed using the International Knee Documentation Committee Subjective Knee Form, and knee-related quality of life was assessed using the Anterior Cruciate Ligament Quality of Life questionnaire.Results: Moderate to vigorous physical activity (MVPA) and steps per day increased from baseline to 3 months (p < .001), with no further increase from 3 to 24 months (p > .05). Time in MVPA did not correlate to patient reported outcome measures at 3, 6, 12, or 24 months (p > .05).Conclusions: Physical activity increased from acute phase to 3 months after non-surgically treated ACL injury, but almost one in four patients did not reach recommended levels of physical activity. Physical activity did not correlate with knee function or quality of life. Patients may need improved support to return to physical activity after ACL injury.