The Efficacy of Tendoactive, Eccentric Training, and the Combination of Both as a Treatment of Achilles Tendinopathy

Inclusion Criteria: * Patients suffering from a gradually evolving painful condition in the Achilles tendon located at the midportion for at least 3 months (Diagnosis based on clinical examination showing a painful thickening of the Achilles tendon located at a level of 2 to 6cm above the tendon insertion, and confirmed by ultrasonography: local thickening of the tendon, irregular tendon structure with hypoechoic areas and irregular fiber orientation). * Men and non-pregnant women aged 18-70 years * Be informed of the nature of the study and provide written informed consent. Exclusion Criteria: * Clinical suspicion of insertional disorders (pain at the site of the insertion of the Achilles tendon on the calcaneum) * Clinical suspicion of an Achilles tendon rupture (Thompson test abnormal and palpable "gap") * Clinical suspicion of plantar flexor tenosynovitis (posteromedial pain when the toes are plantar flexed against resistance) * Clinical suspicion of n.suralis pathology (sensitive disorder in the area of the sural nerve) * Clinical suspicion of peroneal subluxation * Suspicion of internal disorders: spondylarthropathy, gout, hyperlipidemia, Rheumatoid Arthritis and sarcoidosis. * Condition that prevents the patients from executing an active exercise programme * Patient has already performed eccentric exercises, according to the schedule of Alfredson et al (12 weeks) * Patient has already received an injection of PRP for this injury * Patient does not wish, for whatever reason, to undergo one of the two treatments * Known presence of a pregnancy * Condition of the Achilles tendon caused by medications (arising in relation to moment of intake), such as quinolones and statins