The purpose of this randomized controlled trial is to use Shear Wave Elastography (SWE) to assess Achilles tendinopathy and the effectiveness of Blood Flow Restriction (BFR) training in patients with Achilles tendinopathy as measured by Numeric Pain Rating Scale, functional self-report, and objective functional measures. SWE will be utilized to objectively quantify tendon properties and BFR training and eccentric exercise will be utilized to treat Achilles tendinopathy.