Soft Tissue Adapted Biocompatible Hyaluronic Acid, or STABHA™, has demonstrated varying degrees efficacy in patients treated for common musculoskeletal tendinopathies and ligament injuries, such as ankle sprains, lateral elbow tendinopathy, and rotator cuff tendinopathies. Factors associated with prognosis following treatment remain largely unknown. Identifying appropriate patient populations for use of STABHA™ is a necessary first step to facilitate the design of future clinical trials in the management of acute and chronic musculoskeletal soft-tissue injuries.

Inclusion Criteria:

1. Patients 18 years of age or older.

2. Having a STABHA™ injection for the treatment of:

   1. Acute first or second degree ankle sprain (e.g. occurred within the past 48 hours).
   2. Lateral epicondylitis (tennis elbow).

3. Informed consent obtained.

Exclusion Criteria:

1. Medical contraindication to STABHA™.
2. Previous treatment with STABHA™.
3. Ankle or foot fracture.
4. Bilateral ankle sprain.
5. Previous ankle sprain in the past 12 months.
6. Prior surgical management of the ankle or elbow.
7. Current or anticipated incarceration.
8. Terminal illness with expected survival less than 90 days.
9. Currently enrolled in a study that does not permit co-enrollment.
10. Unable to obtain informed consent due to language barriers.
11. Unable to comply with the protocol.
12. Problems, in the judgment of study personnel, with maintaining follow-up with the patient.
13. Prior enrollment in the study.
14. Other reason to exclude the patient, as approved by the Sponsor.