Introduction
Ankle sprains are very common and can cause long-term problems if not treated well. Visiting rehab clinics can be challenging due to time, cost, or travel issues. Mobile health apps make it easier to do exercises at home. However, not many apps are specifically designed for ankle sprains.

Aim of study
To design and validate a mobile health application for home-based musculoskeletal therapy in individuals with ankle sprain, and to evaluate its effectiveness in improving functional ability, reducing pain, and enhancing usability.

Methodology
This randomized controlled trial (Trial Registration: NCT06905418) included 100 participants aged 18–65 years with Grade I or II lateral ankle sprains. Participants were randomly divided into two groups: Group A (control) received conventional rehabilitation care, and Group B (experimental) used a mobile health (mHealth) application for home-based rehabilitation. The intervention lasted 6 weeks with app-guided exercises. Outcomes were assessed at baseline and post-intervention using the Foot and Ankle Ability Measure (FAAM), Numeric Pain Rating Scale (NPRS), and System Usability Scale (SUS).  Data were analyzed using IBM SPSS version 25.
Results
The study included 100 participants (51% male, 49% female) with a mean age of 39.58 ± 14.55 years. The average height was 1.53 m, mean weight was 58.14 kg, and mean BMI was 22.84 kg/m². Right ankle sprains were more common (73%) than left ankle sprains (27%). Post-treatment, the intervention group (Group B) showed greater improvements compared to the control group (Group A). FAAM scores increased from 67.51 to 82.31 (p = 0.000), and NPRS scores decreased from 8.06 to 4.40 (p = 0.000). Between-group comparisons post-intervention indicated statistically significant differences in both FAAM and NPRS scores in favor of Group B (p < 0.05).

Conclusion
The mobile health application effectively improved function and reduced pain in ankle sprain patients, offering a practical alternative to in-person rehabilitation, especially for those with limited access to care.
Key Words: mHealth, Musculoskeletal Therapy, Ankle Sprain, telerehabilitation, Mobile App, Rehabilitation Outcomes, Functional Ability.