Midportion Achilles tendinopathy is a common cause of pain and functional limitation in both athletes and the general population. Progressive tendon loading programs are considered first-line treatment but do not lead to satisfactory outcomes in all patients. Extracorporeal shockwave therapy (ESWT) and platelet-rich plasma (PRP) injections are commonly used interventions for refractory symptoms, yet evidence supporting their combined use is limited particularly in treating Achilles tendon disorders.

This randomized controlled trial will evaluate the effectiveness of a standardized exercise program alone or in combination with PRP injection, ESWT, or both therapies in active adults with midportion Achilles tendinopathy. Participants will be randomized to one of four treatment groups and followed for six months. The primary outcome will assess changes in Achilles tendon symptoms and function using the Victorian Institute of Sport Assessment-Achilles (VISA-A) score. Secondary outcomes will include patient-reported outcomes, physical function testing, ultrasound tendon structure measures, and gait biomechanics.

Midportion Achilles tendinopathy (Mid-AT) is characterized by pain, stiffness, and impaired function resulting from a failed tendon healing response. Progressive loading exercise programs such as the Silbernagel protocol represent the current standard treatment and provide meaningful improvement for many individuals. However, approximately 40% of patients continue to experience persistent symptoms despite rehabilitation.

Extracorporeal shockwave therapy (ESWT) and platelet-rich plasma (PRP) injections are increasingly used in clinical practice to address refractory symptoms. ESWT is proposed to stimulate tissue healing through mechanotransduction and has demonstrated improved outcomes when combined with exercise therapy in some studies. PRP contains concentrated autologous growth factors that may enhance tendon healing through stimulation of extracellular matrix production, angiogenesis, and collagen synthesis.

Despite increasing clinical use, there remains limited evidence evaluating the comparative or combined effects of PRP and ESWT in the treatment of Achilles tendinopathy. Furthermore, few trials have evaluated these therapies within a standardized rehabilitation framework.

The purpose of this randomized controlled trial is to evaluate the effectiveness of exercise therapy alone compared with exercise therapy combined with PRP injection, ESWT, or both interventions in individuals with chronic midportion Achilles tendinopathy. Participants will be randomized to one of four treatment groups: exercise with sham procedures (control), exercise plus PRP injection, exercise plus ESWT, or exercise combined with PRP and ESWT. Participants will be followed for six months to evaluate patient-reported outcomes, tendon structure using ultrasound, physical function testing, and gait biomechanics. This study aims to determine whether PRP, ESWT, or the combination of both treatments provide superior functional recovery compared with exercise-based rehabilitation alone.

Inclusion Criteria:

• Age 18-65 years
• Diagnosis of unilateral midportion Achilles tendinopathy
• Symptoms present for more than 3 months
• VISA-A score <80 at baseline
• Pre-injury physical activity level ≥3 on the Physical Activity Scale
• Ability to participate in rehabilitation program

Exclusion Criteria:

• Symptoms present for less than 3 months
• Prior PRP injection or ESWT treatment to the Achilles tendon within 3 months
• Other lower extremity musculoskeletal injury affecting function
• Symptomatic arthritis affecting the ankle or foot
• Rheumatologic disease or connective tissue disorder
• Coagulopathy or anticoagulant therapy affecting platelet function
• Neuropathy affecting pain perception
• Known cardiac condition contraindicating treatment
• Poorly controlled diabetes (HbA1c >9.0)
• Pregnancy

No identifiable information will be shared outside Mass General Brigham. We will consider publishing a limited deidentified data set at time of publication of our findings.