Comparison of two different exercise programs in mid-portion Achilles tendinopathy: a randomized trial.

Background:
Mid-portion Achilles tendinopathy (AT) is a common overuse injury of the lower extremity, often challenging for patients and therapists. Exercise therapy (i.e. tendon loading) is considered crucial in conservative management, but the most effective exercise program is unknown. Alfredson’s eccentric program and Silbernagel’s concentric-eccentric program have both shown beneficial results in the treatment of AT, but it is unknown whether any program is superior for use in clinical practice.



Objective:
To investigate the difference in effectiveness between the Alfredson eccentric and the Silbernagel concentric-eccentric exercise program on patient-reported function and pain during sports in patients with chronic mid-portion AT after 12 weeks.



Study design:
Prospective multicenter single blind randomized controlled trial.



Study population:
A total of 86 recreational male athletes (18-60 years of age) with a clinical diagnosis of unilateral Achilles tendinopathy will be included.



Intervention:
Two exercise programs will be compared. The first is the Alfredson eccentric exercise program, in which participants perform eccentric heel-drops on their injured leg, twice daily, for three sets of 15 repetitions, and both with a straight and bent knee (i.e. 180 repetitions per day). The other program is the Silbernagel concentric-eccentric program, in which participants perform various 2-legged and 1-legged heel-raising exercises, for three sets of 15 repetitions, but in this program exercises are only performed once daily.



Main study parameters/endpoints:
The primary outcome measures for this study will be patient-reported function in daily activities and sport (measured with the Dutch version of the Victorian Institute of Sport Assessment – Achilles questionnaire) and pain during sports activities (measured with a visual analog scale) after 12 weeks.

It is hypothesized that the Silbernagel exercise program yields at least similar results in terms of symptom reduction (VISA-A score and VAS score)compared with the Alfredson eccentric exercise program.

Baseline, 12 weeks, 6 months, and 12 months.

Two different loading programs for the plantar flexor muscle-tendon unit; i.e. isolated eccentric loading according to the Alfredson program, or a combination of concentric and eccemtric loading according to the Silbernagel program.