This trial is investigating the effects of umbilical cord stem cells in treating tendon repair. The study has being conducted by the Mater Medical Research Institute and Mater Health in Brisbane, Queensland and proposes to recruit nine patients with clinically and ultrasound diagnosed Achilles tendonopathy. Participants will be divided into one of three groups each receiving different doses of stem cells injected directly into damaged tendon. The trial partially complete but is currently on hold. Participants will be monitored for complications and assessed for changes in their clinical condition.