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- Issue 17
- PHYSICAL ACTIVITY AND WORSENING OF RADIOGRAPHIC…
PHYSICAL ACTIVITY AND WORSENING OF RADIOGRAPHIC FINDINGS IN PERSONS WITH OR AT HIGHER RISK OF KNEE OSTEOARTHRITIS
BACKGROUND & OBJECTIVE
Despite the well-established benefit of physical activity in individuals with knee osteoarthritis (OA), only a small proportion of individuals with knee OA meet physical activity guidelines1. This may be potentially explained by the common concern that physical activity will further damage the knee joint and consequently, worsen the patient’s knee OA2. Therefore, the objective of this study was to examine the association between physical activity at baseline and radiographic progression of knee OA over a 4-year period in individuals with or at higher risk for knee OA.
METHODS
The final sample included 1206 participants (1978 knees) with or at higher risk of knee OA (i.e. having one or more risk factors for knee OA such as obesity). Physical activity was measured using an ActiGraph GT1M accelerometer, which was attached on a belt at the waistline during waking hours for seven consecutive days. The following intensity thresholds were used: sedentary activity (0–99 counts/minute), light intensity activity (≥100 counts/minute and <2,020) and moderate to vigorous intensity activity (≥2,020 counts/minute).
Radiographic progression of knee OA was defined as any worsening of the Kellgren-Lawrence grade scores at the 2-year or 4-year period. Multivariable generalized estimating equations (GEE) logistic regression models were used to examine the effect of baseline physical activity on radiographic knee OA progression over a 4-year period, while adjusting for key covariates such as age, sex, BMI, pain, race, previous knee injury, knee surgery and knee alignment.
RESULTS
The majority of the participants’ time was spent in sedentary activity (mean daily activity: 602 ± 86 minutes) and light activity (mean daily activity: 284 ± 75 minutes). Very little time was spent in moderate-vigorous physical activity (mean daily activity:
