Resistance Training and Injection Treatment for Chronic Achilles Tendinopathy

Achilles tendinopathy is a common and often long-lasting injury among exercising individuals. The primary purpose of the study is to compare treatment with supervised or homebased resistance training. The secondary purpose is to compare treatment with either corticosteroid or High Volume Injection (HVI) for those patients not responding to the primary treatment. The tertiary purpose is to evaluate the effect of surgery in those patients not responding to the primary and the secondary treatment. It is hypothesized that: 1. Homebased resistance training is as effective as supervised resistance training for treating chronic achilles tendinopathy 2. HVI injection is better than CS injection for those patients not responding sufficiently to treatment 1 3. Surgery improves symptoms in patients not responding to treatment 1 and treatment 2 Study 1: 90 patients between 18 and 65 years of age with achilles tendinopathy for at least 3 months are randomly assigned to either A. Resistance training at home instructed via a smart phone training app and avoidance of pain aggravating activities for 3 months B. Heavy slow resistance training in the gym instructed by a physiotherapist and avoidance of pain aggravating activities for 3 months Outcomes are change in patient reported outcome (VISA-A) from baseline to 3 and 6 months, ultrasound measured thickness and dopler activity of the achilles tendon, self reported activity level in percentage of the pre injury activity level. After the 3-month training intervention, and for the following 9 months, those patients that not are satisfied with the outcome will have the opportunity to participate in the second part of the study. Study 2: Patients from study 1 which not are satisfied with the outcome are randomly assigned to either A. Same training intervention continued + High Volume Injection (HVI) B. Same training intervention continued + corticosteroid injection After the 4-month and for the following 8 months, those patien