Neuromuscular adaptation to early post-operative, high-intensity, short resistance training of non-operated lower extremity in elderly patients: a randomized controlled trial.

OBJECTIVE To evaluate the short-term effects of high-intensity, task-specific vs regular rehabilitation programme on neuromuscular activity and functional changes in elderly inpatients. DESIGN Single-blind, randomized controlled trial. PATIENTS Sixty-two patients, aged 74.1 (standard deviation (SD) 6.9) years, 12.8 (SD 3.6) days after operation of one lower limb. METHODS Allocation to either high- or regular-intensity strength training of non-operated limb, of 3 weeks duration. OUTCOME MEASUREMENTS ratio of integrated electromyography per weight lifted (mm vastus medialis and lateralis), isometric electromyography (EMG), maximal weight lifted expressed as 1 repetition maximum, torque in Nm and isometric maximal force of uninvolved leg, timed "up and go" test (TUG) and Western Ontario and McMaster Universities (WOMAC) questionnaire. RESULTS Both programmes resulted in significant improvements in: integrated EMG/weight lifted ratio, isometric EMG, 1 repetition maximum, torque and isometric force, TUG performance and WOMAC items (all p < 0.0001, Wilcoxon signed-rank test). Significant differences were found between the high- and regular-intensity groups for integrated EMG/weight lifted (p = 0.026), 1 repetition maximum and torque (p = 0.0014, Wilcoxon rank-sum test). CONCLUSION High-intensity, short-period, early postoperative muscle training has a superior effect on maximal weight lifted by the knee extensors and integrated EMG/weight lifted compared with regular raining. These findings are in accordance with more rapid neuronal adaptation by a high intensity rehabilitation programme.