This is a randomized controlled trial with individuals who have Achilles tendon pain. This study is designed to identify an effective rehabilitation program for Achilles tendon pain that expands access to care for military personnel and to predict treatment response. Limited or delayed access to healthcare can exacerbate the severity of pain and duration of disability due to AT. This is particularly relevant for individuals deployed to battlefield settings or are being seen in busy military treatment facilities. Therefore, it is crucial to identify efficient and effective treatment pathways that maximize healthcare access and facilitate a rapid and pain-free return to full duty.

The objectives of this non-inferiority trial are to identify a rehabilitation program focused on education and exercise for AT that expands access to care for military personnel and to identify factors that predict responses to rehabilitation. The following aims will test our central hypothesis that a single-visit, PT-initiated rehabilitation program will be as effective in improving pain and reducing disability as a multi-visit, PT-guided rehabilitation program for AT and that within two weeks of initiating exercise treatment, early changes in patient-reported outcomes can identify responders.

Specific Aim 1. Determine the efficacy of a single-visit, PT-initiated rehabilitation program vs. a multi-visit, PT-guided rehabilitation program for AT.

Specific Aim 2. Identify early prognostic factors for individuals who experience the greatest improvement in pain and disability by four weeks.

Study Design. A single-blind, two-arm, parallel phase 2 randomized controlled trial is the study approach. Individuals with AT will be randomized to one of two rehabilitation programs: 1) self-guided intervention initiated with a single visit with a physical therapist (PT) via telehealth followed by modules that the participant can complete asynchronously, or 2) PT-guided intervention (standard of care) with six one-on-one telehealth visits. Study will enroll 160 individuals with AT across two sites (University of Iowa Hospitals & Clinics; Carl R. Darnall Army Medical Center, Fort Cavazos) and obtain baseline variables and immediate response at 2-weeks to characterize the sample. Outcomes will be assessed at 4 weeks (primary endpoint), 8 weeks, 26 weeks, and 1 year.

Inclusion Criteria:

• Pain localized to the Achilles tendon (insertion or midportion)
• AT pain greater than or equal to 3/10 with tendon-loading exercise

Exclusion Criteria:

• Younger than 18 years of age or older than 60 years of age
• BMI > 45 kg/m2
• Pain primarily due to a differential diagnosis, including paratendonitis, bursitis (retrocalcaneal or subcutaneous), posterior ankle impingement or os trigonum, irritation or neuropathy of the sural nerve, plantaris tendon involvement)
• Presence of a partial Achilles tendon tear or rupture on imaging or a history of Achilles tendon rupture that was verified by surgical or conservative management
• Attended physical therapy for AT in the past 3 months
• History of steroid injection to lower extremity tendons/fascia, ESWT or any injection to the Achilles tendon region in the past 3 months
• History of taking fluoroquinolones in the past 6 months
• History of surgery or invasive procedure for AT on side enrolling for treatment
• Diagnosed systemic conditions affecting the foot and ankle (e.g., rheumatoid arthritis, ankylosing spondylitis), endocrine disorder with complications (e.g., uncontrolled Type I or II diabetes, diabetic peripheral neuropathy), connective tissue disorder (e.g., Marfan's syndrome, Ehlers Danlos), or pregnancy
• At high risk for falls (four step square test >15 seconds)
• Refusal of randomization or unable or uninterested in completing virtual visits with a webcam or smart phone or completing quizzes and surveys

Consistent with the Congressionally Directed Medical Research Programs Policy on Sharing Data and Research Resources, we will share the primary outcomes data and research resources, such as the rehabilitation handouts and videos. All data that is necessary to validate research outcomes and publications will be preserved and shared to allow other researchers the ability to reproduce the data and obtain additional findings that can advance the results. To ensure that other users can efficiently and accurately use the dataset, we will provide metadata and associated documentation. Information needed to understand the meaning of variable names and information about coding for missing data will be recorded in data dictionaries and readme files that will subsequently be shared alongside final datasets. Protocols, methods, statistical analyses, and any other relevant documentation

IPD will be available within 1 year of completing the study and remain available for at least 10 years

A link to the data will be shared upon publication or within 1 year of completing the study, whichever occurs first. The primary outcome data and resources will be freely available to the public via Iowa Research Online repository. The repository is open access and maintained by the Libraries at the University of Iowa for the preservation and sharing of intellectual work of faculty, students, and staff.