Effects of functional electrostimulation on pain, muscular strength, and functional capacity in patients with osteoarthritis of the knee

Background: Osteoarthritis (OA) of the knee is a common cause of chronic disability in patients with quadriceps muscle weakness. Beneficial effects have been proposed for functional electrostimulation (FES) and exercise at the muscle level. Objectives: The objective of the study was to begin to compare the effects of both therapeutic modalities on quadriceps muscle strength, pain, and functional capacity in patients with OA of the knee and to prove whether the combination of these modalities provides greater benefits than the use of each therapeutic modality alone. Methods: This pilot study included 37 patients with OA of the knee who were assessed at baseline and at 8 weeks, accounting for the following variables: body mass index, knee pain (measured using a VAS), WOMAC, quadriceps strength (measured using a dynamometer) and 6-minute walk test. Patients were randomized into 3 groups: (A) 8 patients who received FES 3 times per week; (B) 10 patients recruited into a twice-a-week physical training program; and (C) 8 patients under combined therapy; 29.7% of patients were lost to follow-up due to noncompliance with the treatment plan, leaving a total of 26 patients at 8 weeks. Results: Pain and WOMAC improved in all 3 groups; strength improved significantly in the exercise-only group; the FES + exercise combination improved strength significantly when compared with the individual therapeutic procedures. Conclusions: FES merits a larger placebo-controlled study as it may prove to be useful patients with OA of the knee; the combination with exercise was helpful in improving muscle strength. This technique may be considered in patients who are unable to carry out physical activity due to health problems or in those who are not interested in physical activity.