Anja Ruhdorfer1, Wolfgang Wirth, Adam G Culvenor, Felix Eckstein. 1. From the Institute of Anatomy, Department of Imaging and Functional Musculoskeletal Research, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria (AR, WW, AGC, FE); Department of Orthopedic Surgery and Traumatology, Landesklinik Tamsweg, Tamsweg, Austria (AR); and La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, School of Allied Health, Bundoora, Melbourne, Victoria, Australia (AGC).
Abstract
OBJECTIVE: The aim of the study was to investigate whether muscle strength declines before or concurrent with incident knee pain in subjects with and without radiographic knee osteoarthritis. DESIGN: Osteoarthritis initiative participants with incident knee pain (occurrence of infrequent/frequent knee pain during the past 12 mos at two consecutive follow-up time points (either years Y3 + Y4 or Y4 + Y5) were compared with controls (no incident knee pain) with 2-yr changes in knee extensor strength during BL➔Y2 (before) and Y2➔Y4 (concurrent). RESULTS: Two hundred two knees (49% women, 40% radiographic knee osteoarthritis) displayed incident pain, and 439 did not (46% women, 23% radiographic knee osteoarthritis). Women with radiographic knee osteoarthritis displayed a significantly greater (P = 0.04) reduction in knee extensor strength concurrent with incident pain compared with controls (mean = -17.6 N vs. +4.5 N), but men did not. A similar trend was observed in women without radiographic knee osteoarthritis, but this was not statistically significant (P = 0.08). There was no significant relationship with change in extensor strength before incident pain (P ≥ 0.43). CONCLUSIONS: These results suggest that in women, incident knee pain is accompanied by a concurrent reduction in knee extensor strength, whereas loss in strength does not precede incident knee pain. The findings encourage interventional studies that attempt to attenuate a decline in extensor strength once knee symptoms occur.
OBJECTIVE: The aim of the study was to investigate whether muscle strength declines before or concurrent with incident knee pain in subjects with and without radiographic knee osteoarthritis. DESIGN: Osteoarthritis initiative participants with incident knee pain (occurrence of infrequent/frequent knee pain during the past 12 mos at two consecutive follow-up time points (either years Y3 + Y4 or Y4 + Y5) were compared with controls (no incident knee pain) with 2-yr changes in knee extensor strength during BL➔Y2 (before) and Y2➔Y4 (concurrent). RESULTS: Two hundred two knees (49% women, 40% radiographic knee osteoarthritis) displayed incident pain, and 439 did not (46% women, 23% radiographic knee osteoarthritis). Women with radiographic knee osteoarthritis displayed a significantly greater (P = 0.04) reduction in knee extensor strength concurrent with incident pain compared with controls (mean = -17.6 N vs. +4.5 N), but men did not. A similar trend was observed in women without radiographic knee osteoarthritis, but this was not statistically significant (P = 0.08). There was no significant relationship with change in extensor strength before incident pain (P ≥ 0.43). CONCLUSIONS: These results suggest that in women, incident knee pain is accompanied by a concurrent reduction in knee extensor strength, whereas loss in strength does not precede incident knee pain. The findings encourage interventional studies that attempt to attenuate a decline in extensor strength once knee symptoms occur.
Authors: Eva Steidle-Kloc; Wolfgang Wirth; Natalie A Glass; Anja Ruhdorfer; Sebastian Cotofana; Felix Eckstein; Neil A Segal Journal: Am J Phys Med Rehabil Date: 2015-10 Impact factor: 2.159
Authors: Matthew J Delmonico; Tamara B Harris; Marjolein Visser; Seok Won Park; Molly B Conroy; Pedro Velasquez-Mieyer; Robert Boudreau; Todd M Manini; Michael Nevitt; Anne B Newman; Bret H Goodpaster Journal: Am J Clin Nutr Date: 2009-10-28 Impact factor: 7.045