Association of objectively measured physical activity with combined bilateral knee and low-back pain in older adults with knee osteoarthritis: A cross-sectional study.

OBJECTIVE: Knee pain (KP) and low-back pain (LBP) are common sites of pain and major public health issues among older adults. We investigated the combined association of bilateral KP and LBP with objectively measured physical activity (PA) among adults with knee osteoarthritis (OA). METHODS: We recruited 150 knee OA adults and measured steps and PA intensity, including sedentary behavior (SB), low PA (LPA), and moderate-to-vigorous PA, using an accelerometer. KP and LBP were measured using a numerical rating scale. They were classified into 4 groups based on the presence of KP and LBP: with the only unilateral KP (UKP), with the combined UKP and LBP (UKP and LBP), with the bilateral KP (BKP), and with the combined bilateral KP and LBP (BKP and LBP). One-way analysis of covariance was performed to compare physical activity variables (intensity or steps) between the four groups. RESULTS: Overall, 126 patients were enrolled. The prevalence of UKP, BKP, UKP and LBP, and BKP and LBP were 29.4%, 23.8%, 18.3%, and 28.6%. The proportion of SB was higher in the BKP and LBP group than in the other groups (F = 6.51, p < 0.01). The proportion of LPA was lower in the BKP and LBP group than in the other groups (F = 6.21, p < 0.01). CONCLUSIONS: The proportions of SB and LPA were significantly worse in knee OA adults with BKP and LBP than in those with UKP. Our findings may be a basis for considering knee OA adults for improving PA.

Effect of preoperative sedentary behavior on clinical recovery after total knee arthroplasty: a prospective cohort study.

OBJECTIVES: Prolonged sedentary behavior (SB) may affect clinical improvements following total knee arthroplasty (TKA). We aim to assess preoperative SB effect on improvements in clinical outcomes after TKA. We hypothesized that patients with high proportion of preoperative SB have small improvements in clinical outcomes after TKA. METHODS: We recruited 115 adults with knee osteoarthritis (OA), planning to undergo TKA. Knee-specific functional outcomes were assessed using the new knee society score (KSS), including total score, symptoms, patient satisfaction, patient expectations, and functional activities. Gait function was assessed using the timed up and go (TUG) test. SB was measured using a triaxial accelerometer. Multiple linear regression analysis was performed to investigate preoperative SB effect on improvements in clinical outcomes 6 months postoperatively by adjusting for several factors as potential confounders. RESULTS: Of 115 patients, 82 were included. High proportion of preoperative SB had a significant negative effect on recovery at 6 months in the new KSS total score [ß, -0.83, 95% confidence interval (CI), -1.53 to -0.12; p = 0.02], symptoms (-0.15, -0.28 to -0.02; p = 0.03), patient satisfaction (-0.22, -0.42 to -0.02; p = 0.03), and functional activities (-0.40, -0.76 to -0.04; p = 0.03) after adjusting for potential confounders. CONCLUSIONS: A high proportion of preoperative SB was a risk factor for reduced improvements in knee-specific functional outcomes after TKA. To prevent poor functional recovery after TKA, it is essential to understand the preoperative lifestyle factors and intervene proactively during acute postoperative phase in patients with high SB proportion.Key Points• Preoperative high proportion of SB had a negative effect on improvement in new KSS total scores, symptoms, patient satisfaction, and functional activities.• When considering clinical outcomes after TKA, clinicians should closely monitor patients with high proportions of preoperative SB to prevent poor functional recovery.