Achilles tendinopathy is highly prevalent in runners, but its evolution is not easily predictable. The aim of this study is to evaluate the impact of clinical and social factors on the prognosis of acute (less than 3 months) Achilles tendinopathy in runners. Runners will be evaluated in person twice. At their first visit, data related to their training (frequency, intensity, …), their running pattern (cadence, foot contact angle) and shoes (minimalist index) will be collected. Moreover, an ultrasound evaluation of Achilles tendon will be performed. At one, two and three months after their initial evaluation, participants will receive a link to complete an online survey about their pain. Three months after their initial evaluation, a second ultrasound of Achilles tendon will be performed.