Effects of Physical Activity in Knee and Hip Osteoarthritis: A Systematic Umbrella Review

Abstract

Introduction: We conducted a systematic umbrella review to evaluate the literature relating to effects of physical activity on pain, physical function, health-related quality of life, comorbid conditions and osteoarthritis (OA) structural disease progression in individuals with lower-extremity OA.

Methods: Our primary search encompassed 2011 to February 2018 for existing systematic reviews (SR), meta-analyses (MA) and pooled analyses dealing with physical activity including exercise (not mixed with any other intervention and compared to a no-activity control group). A supplementary search encompassed 2006 to February 2018 for original research related to physical activity (including exercise) and lower limb OA progression. Study characteristics were abstracted, and risk of bias was assessed.

Results: Physical activity decreased pain and improved physical function (strong evidence) and improved health-related quality of life (moderate evidence) among people with hip or knee OA relative to less active adults with OA. There was no evidence to suggest accelerated OA progression for physical activity below 10,000 steps per day. Both physical activity equivalent to the 2008 Physical Activity Guidelines for Americans (150 min·wk of moderate-intensity exercise in bouts ≥10 min) and lower levels of physical activity (at least 45 total minutes per week of moderate-intensity) were associated with improved or sustained high function. No SR/MA addressing comorbid conditions in OA were found. Measurable benefits of physical activity appeared to persist for periods of up to 6 months following cessation of a defined program.

Conclusions: People with lower-extremity OA should be encouraged to engage in achievable amounts of physical activity, of even modest intensities. They can choose to accrue minutes of physical activity throughout the entire day, irrespective of bout duration, and be confident in gaining some health and arthritis-related benefits.

Figure 1.

Effects of Land-based Exercise on Pain, Physical Function and Health-Related Quality of Life (QOL) in Knee OA. Reproduced from “Exercise for osteoarthritis of the knee: a Cochrane systematic review”, Marlene Fransen et al., 49, 2015 with permission from BMJ Publishing Group Ltd. Negative Standardized Mean Differences (SMDs) represent improvements in pain and physical function (lower scores represent better pain and/or physical function) whereas positive SMDs represent improvements in health-related quality of life (HRQoL, higher scores represent better HRQoL).

Figure 2.

Effects of Aquatic Exercise on Pain, Physical Function and Health-Related Quality of Life (HRQoL) in Knee OA. Reproduced from EM Bartels, “Aquatic exercise for the treatment of knee and hip osteoarthritis”, Cochrane Database of Systematic Reviews, John Wiley and Sons. Copyright © 2016 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd/. A multitude of measures were used in the included studies; standardized instruments used most often were WOMAC for pain and function and SF-36, SF-12 or SF-8 for physical function. Negative Standardized Mean Differences (SMDs) represented improvements in pain, physical function and/or HRQoL (lower scores mean better pain, physical function and/or HRQoL).

Figure 3.

Interaction of Underlying Joint Pathology by MRI and Ambulatory Physical Activity Amounts (Step Counts) on OA Progression, as Shown on MRI. Greater meniscal pathology scores, presence of bone mineral lesions (BML) and less cartilage volume all indicate more severe disease. BML are areas of increased signal adjacent to the subcortical bone at the medial tibial, medial femoral, lateral tibial, and lateral femoral sites and indicate more severe joint pathology. All figures show an interaction effect, wherein for those individuals with less baseline meniscal pathology, steps are not related to pathology score increases. In contrast, in adults with greater baseline pathology scores, a greater percent of adults with more than 10,000 steps per day show worsening of pathology scores over time (26%) compared to adults with fewer than 10,000 steps day (10%). Reproduced from “The association between objectively measured physical activity and knee structural change using MRI”, Dawn A Dore et al., 72, 2013 with permission from BMJ Publishing Group Ltd.