A Quantitative Comparative Assessment of the Immediate Response to High Frequency Ultrasound and Low Frequency Ultrasound (‘Longwave Therapy’) in the Treatment of Acute Ankle Sprains

Abstract

Summary This paper describes a prospective randomised trial to compare the relative efficacy of high frequency ultrasound (3 MHz) and low frequency ultrasound (45 kHz) in the treatment of unilateral acute ankle sprains. A placebo group, which received ‘sham’ ultrasound was also included in the trial. Objective, quantified measurements of the patients’ gait were made before treatment and immediately following treatment, using the Gaitway system. The results show that the group treated with longwave showed a much greater improvement immediately following therapy with statistically highly significant improvement in length of stride, symmetry of swing phase duration, cadence and walking velocity. The enhanced response was evident also from follow-up measurements using Gaitway at three days after treatment and by clinical impressions and patients’ commentaries. We consider the difference between these forms of therapy to be significant and consequently suggest that the name ‘longwave therapy’ be used to describe the low frequency treatment modality. This paper describes a prospective randomised trial to compare the relative efficacy of high frequency ultrasound (3 MHz) and low frequency ultrasound (45 kHz) in the treatment of unilateral acute ankle sprains. A placebo group, which received ‘sham’ ultrasound was also included in the trial. Objective, quantified measurements of the patients’ gait were made before treatment and immediately following treatment, using the Gaitway system. The results show that the group treated with longwave showed a much greater improvement immediately following therapy with statistically highly significant improvement in length of stride, symmetry of swing phase duration, cadence and walking velocity. The enhanced response was evident also from follow-up measurements using Gaitway at three days after treatment and by clinical impressions and patients’ commentaries. We consider the difference between these forms of therapy to be significant and consequently suggest that the name ‘longwave therapy’ be used to describe the low frequency treatment modality.