Mechanical vibration in the rehabilitation of patients with reconstructed anterior cruciate ligament

Aim. More and more, mechanical vibration exercise is being used in both sports training and rehabilitation therapy. Many studies have reported an increase in the muscle performance of subjects after whole-body vibration, but so far none have evaluated the possibility to improve the recovery of muscle strength after anterior cruciate ligament reconstruction. The contraindications to this type of treatment are related to the administration of higher vibration frequency for periods much longer than those foreseen by our protocol. However, numerous studies have found this treatment can offer the benefit of reduced frequency and intensity of the electromyographic tracing, accompanied by an increase in muscle strenght similar to that obtained after strength training with overload. Hormonal response was also seen to differ from that after strength training with overload because of a major increase in blood concentrations of growth hormone and a reduction of cortisol. The aim of our study was to evaluate the usefulness of mechanical vibration in the rehabilitation of patients who received reconstruction of the anterior cruciate ligament. Methods. In this study 20 subjects were enrolled and randomly divided into 2 groups (10 patients and 10 control subjects). The subjects received 5 daily administrations of whole-body vibration (30 Hz frequency for 1 minute) over a 2-week period. Muscle force during extension of both lower limbs was evaluated by isometric contraction for 5 seconds. Results. Different results were obtained: the treatment group showed a mean increase in muscle strength and in mean force peaks, both statistically significant (p