OBJECTIVE: Avoidance of activity is hypothesized to lead to muscle weakness and consequently, to physical disability. This study was undertaken to validate the avoidance model by providing evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and physical disability in patients with osteoarthritis (OA) of the knee. METHODS: Data on avoidance of activity, observed physical disability, and muscle strength of the knee in 107 patients with knee OA were analyzed. A series of regression analyses was performed to establish the mediating role of muscle weakness. First, the effect of avoidance of activity on the level of disability was assessed. Next, the relationship between avoidance of activity and muscle strength was established. Finally, the mediating role of muscle strength could be established if the effect of avoidance of activity on disability decreased when muscle strength was taken into account. RESULTS: Initially, avoidance of activity accounted for 21.5% of variance in disability. Avoidance of activity also accounted for 3.9% of variance in muscle strength. After muscle strength was taken into account, the variance in disability accounted for by avoidance of activity was reduced from 21.5% to 15.7%. Thus, the criteria for establishing the mediating role of muscle strength were met. CONCLUSION: The results of this study provide evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and disability in patients with knee OA.
OBJECTIVE: Avoidance of activity is hypothesized to lead to muscle weakness and consequently, to physical disability. This study was undertaken to validate the avoidance model by providing evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and physical disability in patients with osteoarthritis (OA) of the knee. METHODS: Data on avoidance of activity, observed physical disability, and muscle strength of the knee in 107 patients with knee OA were analyzed. A series of regression analyses was performed to establish the mediating role of muscle weakness. First, the effect of avoidance of activity on the level of disability was assessed. Next, the relationship between avoidance of activity and muscle strength was established. Finally, the mediating role of muscle strength could be established if the effect of avoidance of activity on disability decreased when muscle strength was taken into account. RESULTS: Initially, avoidance of activity accounted for 21.5% of variance in disability. Avoidance of activity also accounted for 3.9% of variance in muscle strength. After muscle strength was taken into account, the variance in disability accounted for by avoidance of activity was reduced from 21.5% to 15.7%. Thus, the criteria for establishing the mediating role of muscle strength were met. CONCLUSION: The results of this study provide evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and disability in patients with knee OA.
Authors: Pao-Feng Tsai; Jason Y Chang; Cornelia Beck; Yong-Fang Kuo; Francis J Keefe; Karl Rosengren Journal: Complement Ther Med Date: 2015-06-09 Impact factor: 2.446
Authors: Jasmijn F M Holla; Diana C Sanchez-Ramirez; Marike van der Leeden; Johannes C F Ket; Leo D Roorda; Willem F Lems; Martijn P M Steultjens; Joost Dekker Journal: J Behav Med Date: 2014-05-20
Authors: James S Andrews; Laura Trupin; Gabriela Schmajuk; Jennifer Barton; Mary Margaretten; Jinoos Yazdany; Edward H Yelin; Patricia P Katz Journal: Arthritis Care Res (Hoboken) Date: 2015-08 Impact factor: 4.794
Authors: Clayon B Hamilton; Monica R Maly; Jessica M Clark; Mark Speechley; Robert J Petrella; Bert M Chesworth Journal: Physiother Can Date: 2013 Impact factor: 1.037
Authors: Carmelita J Colbert; Jing Song; Dorothy Dunlop; Joan S Chmiel; Karen W Hayes; September Cahue; Kirsten C Moisio; Alison H Chang; Leena Sharma Journal: Arthritis Rheum Date: 2012-05
Authors: Lynn M Martire; Mary Ann Parris Stephens; Jacqueline Mogle; Richard Schulz; Jennifer Brach; Francis J Keefe Journal: Ann Behav Med Date: 2013-04
Authors: Rebecca A Shelby; Tamara J Somers; Francis J Keefe; Brenda M DeVellis; Carol Patterson; Jordan B Renner; Joanne M Jordan Journal: Arthritis Care Res (Hoboken) Date: 2012-01-30 Impact factor: 4.794
Authors: Cindy Veenhof; Cornelia H M Van den Ende; Joost Dekker; Albère J A Köke; Rob A Oostendorp; Johannes W J Bijlsma Journal: Int J Behav Med Date: 2007