The aim of this study was to investigate the association between muscle strength and physical activity level in people with knee osteoarthritis (OA), and determine whether this association is mediated by pain-related fear of movement (kinesiophobia) and self-reported pain. Cross-sectional data from 37 subjects (age 58.8 ± 8.6 years, 25F/12M, BMI 33.5 ± 6.4 kg/m 2 ) with OA of the knee were used. Isometric knee extensor and flexor muscle strength were measured using an isokinetic dynamometer. Physical activity, kinesiophobia, and pain were assessed by self-report using the University of California, Los Angeles activity rating scale, Tampa Scale for Kinesiophobia, and The Knee Injury and Osteoarthritis Outcome Score pain subscale, respectively. The associations between strength measures, physical activity, kinesiophobia, and pain scores, were modeled by performing a parallel multiple mediation analysis and the significance of mediational effects (kinesiophobia and pain) were tested using a bootstrap approach. Lower knee flexion and extension strength were associated with lower physical activity scores and these relationships were mediated by higher kinesiophobia scores (more fear) but not pain scores. Knee extension strength was directly associated with physical activity scores after controlling for kinesiophobia and pain scores. These results suggest that muscle strength can influence physical activity directly and indirectly through fear of movement.Assessing these measures together in this population may help clinicians identify patients that are more likely to avoid physical activities due to not only muscle weakness but also fear of movement.

Context: Plantar fasciitis (PF) is a common condition in active individuals. The lack of agreement on PF etiology makes treatment challenging and highlights the importance of understanding risk factors for preventive efforts. Objective: The purpose of this systematic review and meta-analysis was to determine what factors may put physically active individuals at risk of developing PF. Data Sources: CENTRAL, CINAHL, EMBASE, Gray Lit, LILACS, MEDLINE (PubMed), ProQuest, Scopus, SPORTDiscus, and Web of Science were searched through April 2018 and updated in April 2020. Study Selection: Studies were included if they were original research investigating PF risk factors, compared physically active individuals with and without PF, were written in English, and were accessible as full-length, peer-reviewed articles. Study Design: Systematic review and meta-analysis. Level of Evidence: Level 3, because of inconsistent definitions and blinding used in the included observational studies. Data Extraction: Data on sample characteristics, study design and duration, groups, PF diagnosis, and risk factors were extracted. The methodological quality of the studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology statement. When means and standard deviations of a particular risk factor were presented 2 or more times, that risk factor was included in the meta-analysis. Results: Sixteen studies were included in the systematic review and 11 risk factors in the meta-analysis. Increased plantarflexion range of motion (weighted mean difference [MD] = 7.04°; 95% CI, 5.88-8.19; P < 0.001), body mass index (MD = 2.13 kg/m2; 95% CI, 1.40-2.86; P < 0.001; I2 = 0.00%), and body mass (MD = 4.52 kg; 95% CI, 0.55-8.49; P = 0.026) were risk factors for PF. Conclusion: Interventions focused on addressing a greater degree of plantarflexion range of motion, body mass index, and body mass and their load on the force-absorbing plantar surface structures may be a good starting point in the prevention and treatment of active individuals with PF.

The findings support implementing a hip-or knee-muscle-strengthening program for the treatment of PFP. Both programs improve pain, function, strength, and core endurance in the short term with moderate- and long-term benefits of improved pain and function and low PFP recurrence.

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Physical activity is important for physical function and pain relief in people with lower extremity osteoarthritis (OA). Unfortunately, people with OA are not as active as their peers without OA. The objective of this study was to determine whether aerobic capacity and fatigability are associated with physical activity in women with hip OA. We conducted a cross‐sectional analysis of 36 women with hip OA. We assessed aerobic fitness as predicted VO2max from a 6‐min walk test. We assessed fatigability using a treadmill test. Finally, we assessed self‐reported physical activity using the UCLA activity scale and quantified steps per day and activity intensity using accelerometers. We used Pearson correlations to determine associations. We used regression analysis to determine whether fatigability mediated the association between aerobic fitness and physical activity. On average, subjects were moderately active via the UCLA score (5.2 ± 1.3 out of 10). Aerobic fitness (R = 0.582, p < .001) and fatigability (R = 0.516, p =.003) were significantly correlated with UCLA scores. However, aerobic fitness was the best predictor of UCLA scores, as well as sedentary time, and time spent in light activity. Fatigability was not a mediator between aerobic fitness and UCLA scores. Aerobic fitness and fatigability may be modifiable barriers to physical activity in people with OA. Future interventional studies should examine whether improving aerobic fitness improves physical activity or fatigability.