Concentric and Eccentric Resistance Training Comparison on Physical Function and Functional Pain Outcomes in Knee Osteoarthritis A Randomized Controlled Trial

Objective The aim of the study was to compare the effectiveness of concentrically focused resistance training to eccentrically focused resistance training on physical function and functional pain in knee osteoarthritis. Design This is a randomized, single-blinded controlled 4-mo trial. Older adults with knee osteoarthritis (N= 88; 68.3 +/- 6.4 yrs, 30.4 +/- 6.9 kg/m(2), and 67.4% women) were randomized to eccentrically focused resistance training, concentrically focused resistance training, or no-exercise control. Main outcomes included chair rise time, stair climb time, 6-min walk test distance, temporal-spatial parameters of gait, community ambulation, and functional pain. Results Leg muscle strength improved in both training groups compared with no-exercise control. There were no significant group x time interactions for any functional performance score (chair rise time, stair climb time, 6-min walk test distance, gait parameters, community ambulation). Compared with no-exercise control, functional pain scores were reduced for chair rise (-38.6% concentrically focused resistance training, -50.3% eccentrically focused resistance training vs. +10.0%) and stair climb (-51.6% concentrically focused resistance training, -41.3% eccentrically focused resistance training vs. +80.7%; allP< 0.05). Pain scores were reduced during the 6-min walk and in early recovery with concentrically focused resistance training compared with the remaining two groups (P< 0.05). Conclusions Either resistance exercise type improves activity-related knee osteoarthritis pain, but concentrically focused resistance training more effectively reduced severity of ambulatory pain and pain upon walking cessation.