Aims: To evaluate changes in the bioelectrical activity of thigh muscles in concentric and eccentric movements of a sit-to-stand test in women with knee osteoarthritis after a preoperative home exercise program (HEP). Secondly, to compare patients with healthy controls. Methods: Seventeen women with knee osteoarthritis and ten healthy controls participated. The bioelectrical activity of thigh muscles during sit-to-stand test and isometric maximal voluntary contraction force of leg extensor muscles were measured. Results: Post-HEP, the knee osteoarthritis group demonstrated lower bioelectrical activity of antagonist muscles in the concentric and eccentric movements, and reduced asymmetry in muscle activation between limbs. Poorer results were noted compared to controls pre-and post-HEP. Conclusions: In knee osteoarthritis patients, the bioelectrical activity of thigh muscles during the sit-to-stand test improves after eight weeks of preoperative HEP. Preoperative HEP reduces co-activation of thigh muscles and activation asymmetry between limbs in concentric and eccentric movements of a sit-to-stand task.

Background and Objectives: The increased prevalence of knee osteoarthritis (OA) and need for total knee arthroplasty (TKA) indicate a growing need for effective prehabilitation. The effect of preoperative home exercise programs (HEPs) on gait in patients with severe knee OA is under-investigated. This study aimed to evaluate the influence of an 8-week preoperative HEP on gait characteristics, leg extensor muscle strength, knee function, and health status in women with severe knee OA scheduled for TKA and to compare them with healthy control data. Material and Methods: Eighteen women with severe knee OA (KOA, aged 61.8 ± 1.6 years) and ten age-matched healthy women (CON) participated in this study. The KOA group performed an HEP with 15 exercises aimed at improving lower limb muscle strength, motion, balance, and coordination. Gait spatiotemporal and kinetic characteristics during the loading response, isometric leg extensor strength, knee active range of motion (AROM), and The Western Ontario and McMaster Universities Arthritis Index (WOMAC) were investigated. Associations between characteristics were analyzed. Results: Improvements in ground reaction force (GRF) during the loading response of gait, leg extensor muscle strength, the knee AROM, and the WOMAC index were found post-HEP. The KOA group demonstrated lower (p < 0.05) spatiotemporal and GRF characteristics than the CON group. Knee extension moment (KEM) was lower pre-HEP (p < 0.05) but did not differ significantly from the CON group post-HEP. Gait characteristics and WOMAC were associated with leg extensor muscle strength and knee AROM and pain in the KOA group. Conclusions: An eight-week preoperative HEP improved GRF and KEM during the loading response of gait, muscle strength, knee function, and self-reported knee OA-related health status in women with severe knee OA. Preoperative HEP before TKA, focusing on leg extensor muscle strength, range of motion, and pain relief, is an effective alternative to supervised exercise therapy in women with severe knee OA.