Effects of Early Combined Eccentric-Concentric Versus Concentric Resistance Training Following Total Knee Arthroplasty

To investigate the effects of early combined eccentric-concentric (ECC-CON) or concentric (CON) resistance training following total knee arthroplasty (TKA). Patients who underwent a primary TKA were randomly assigned to an ECC-CON group (n=16) or a CON group (n=18). All patients received early, progressive resistance training with five sessions per week for 2 weeks starting 2 weeks after TKA. Isometric knee flexor and extensor strength of the surgical and non-surgical knees, instrumental gait analysis for spatiotemporal parameters, 6-Minute Walk Test (6MWT), Timed Up and Go Test (TUG), Timed Stair Climbing Test (SCT) were used to evaluate performance-based physical function. The Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and EuroQOL five dimensions (EQ-5D) questionnaire were used to evaluate self-reported physical function and self-reported quality of life. All patients underwent these evaluations before and 1 month after TKA. The ECC-CON group showed clinically meaningful improvements in extensor peak torque (PT) of the non-surgical knee, gait speed, and 6MWT from preoperative values. The CON group had an increase in H/Q ratio of the surgical knee and improvement in SCT-ascent postoperatively. Both groups showed significant improvements in WOMAC-Pain, function, and EQ-5D scores. Although extensor PT of the surgical knee did not reach the preoperative level in either group, the postoperative change was significantly less in the ECC-CON group than the CON group. Early combined ECC-CON resistance training minimizes the loss in quadriceps strength of the surgical knee and improves endurance and gait speed after TKA.