Randomised controlled trial of electrical stimulation of the quadriceps after proximal femoral fracture

Abstract

Background and aims: Proximal femoral fracture is often associated with long-term residual disability. Quadriceps weakness may be a factor in poor outcome. This study aimed to determine whether training of the quadriceps using electrical stimulation (ES) increases leg extensor power and decreases disability in elderly subjects rehabilitating after fracture. Methods: A single-blind randomized controlled trial of elderly postsurgical proximal femoral fracture patients, comparing 6 weeks of supplementary electrical stimulation of the quadriceps (15 patients) to usual physiotherapy alone (11 patients). The electrical stimulation on:off duty cycle was 7:23 seconds, with 36 cycles per session, given daily as an in-patient and twice weekly after discharge. The primary outcome measure was change in leg extensor power (Nottingham Power Rig). Functional mobility (Elderly Mobility Scale), disability (Barthel Index) and health status (Nottingham Health Profile) were also measured. Results: There was no significant difference in change in leg extensor power, or any other outcome measure, in the ES group compared to usualcare controls. Fractured leg extensor power increased by 10.9 (standard error of the mean 2.1) Watts at 6 weeks in the ES group compared to 15.3 (5.5) in the controls (mean adjusted difference −3.1, 95% CI −7.8, 1.6 Watts). Only 3 (20%) of the intervention patients tolerated sufficient stimulation intensity to produce repetitive knee extension, while 11 (73%) sustained palpable or visible contractions with no leg movement. Conclusion: A 6-week program of electrical stimulation of the quadriceps did not increase leg extensor power, or reduce disability, in elderly patients rehabilitating after surgical fixation of proximal femoral fracture. In many patients local discomfort limited the intensity of electrical stimulation that could be delivered.