No association exists between long-term strenuous physical activity and incident radiographic knee osteoarthritis (KOA), according to a study reported in JAMA Network Open.
This secondary analysis from a prospective cohort from the Osteoarthritis Initiative (OAI) studied 1,194 patients at high risk of, but without radiographic evidence for, KOA.
Inclusion criteria were Kellgren and Lawrence grade of 0 in both knees and completion of a PASE (Physical Activity Scale for the Elderly) questionnaire, which enquired about frequency and duration of exercise over the previous seven days, estimated over an eight-year period.
Patients were classified into the persistently no exercise subgroup (0 h/wk)(49.7%), the low (29.6%), or slightly improving subgroup (1-2 h/wk).
More than 40 per cent were classified into moderate (32.3%) to high (10.1%) frequency of extensive sitting subgroup, who were older, had higher BMI, and more severe knee pain. Being a college graduate and having stronger quadriceps were each associated with an increased likelihood of membership in the high, improving exercise subgroup.
Long-term engagement in low-to-moderate physical activities (adjusted odds ratio [OR] 0.69; 95% CI 0.48-1.01) or any strenuous physical activities (adjusted OR 0.75; 95% CI 0.53-1.07) was not associated with 10-year incident radiographic KOA.