A single-blind randomized clinical trial comparing calf muscle stretches with cryotherapy, eccentric exercises with cryotherapy, and combined therapy on pain, functional disability, and ankle range of motion in young athletes with Sever’s disease

To evaluate and compare the effectiveness of calf muscle stretches with cryotherapy, eccentric exercises with cryotherapy, and their combination (combined therapy with cryotherapy) on pain intensity, functional disability, and ankle range of motion in young athletes.

Single-blind, parallel-group randomized clinical trial

This single-blind, parallel-group randomized clinical trial was conducted at a school sports complex in Gujranwala, Pakistan (June–September 2025). Participants attended three supervised 17–20minute sessions per week for six weeks (18 total sessions). Outcomes were assessed at baseline and within 48 hours post-intervention.

Of 150 young athletes screened, inclusion criteria were: age 8–15 years, heel pain ≥2 weeks, pain at Achilles insertion on the calcaneus, and heel tenderness/swelling. Exclusion criteria were recent heel trauma/fracture, direct injury, neurological disorders, or systemic disorders.

All groups received 18 sessions over six weeks (three sessions/week, 17–20 minutes each, including 2–3 minute warm-up). Cryotherapy (cold pack to heel for 5–10 minutes) was applied after each session. - Group A (Stretches): Three calf stretches (standing wall, bent-knee, soleus) — 3 sets of 6–10 repetitions, hold 20–30 seconds. Group B (Eccentric): Heel drops (3×10), sumo squats with pulses (3×6), and eccentric toe walk (3×10–15 steps). Group C (Combined): Both stretch and eccentric protocols.

Primary outcomes: pain intensity (NPRS, 0–10) and functional disability (OXAFQ, 0–100). Secondary outcome: ankle ROM (dorsiflexion, plantar flexion, inversion, eversion) measured via goniometer. Assessments at baseline and 48 hours post-intervention (6 weeks).

Method of randomization: Not explicitly named (simple or block not specified), but participants were randomly assigned in a 1:1:1 ratio using an online tool Unit of randomization: Individual participant Randomization strata: None described Tools used for randomization: Online Research Randomizer tool (www.randomizer.org) How the random sequence was built: The tool generated the allocation sequence; unique identification codes were assigned to all participants Allocation concealment: Yes — outcome assessors were blinded to group allocation. However, participants and therapists could not be blinded due to the nature of exercise interventions

This study employed a single-blind design. Due to the nature of the interventions, participants and treating physiotherapists cannot be blinded to group allocation. However, the assessor responsible for collecting outcome measures (pain intensity, functional disability, and ankle range of motion) will be blinded to treatment allocation throughout the study. Participants will be instructed not to disclose their assigned intervention to the assessor. In addition, data analysis will be conducted using coded group labels (e.g., Group A, B, and C) to maintain assessor and analyst blinding until the completion of statistical analyses.

Deidentified individual participant data (IPD) collected for all primary and secondary outcomes, including: NPRS pain scores, OXAFQ functional disability scores, and ankle range of motion measurements (dorsiflexion, plantar flexion, inversion, eversion) at baseline and 6 weeks post-intervention. Also includes demographic data (age, gender) and group allocation.

Data will become available starting 6 months after publication of the main trial results and will remain available for 5 years.

Data will be shared with researchers working in academic institutions who provide a methodologically sound proposal. Requests from commercial entities will be considered on a case-by-case basis.

Data may be used for systematic reviews, meta-analyses, secondary analyses of pediatric musculoskeletal conditions, and validation of outcome measures. Requests will be reviewed by the principal investigators (Dr. Shumana Zakaullah, Dr Saada Asif and Dr Sajjan Iqbal) based on scientific merit and ethical approval from the requester's institutional review board.

Requests should be directed to the corresponding author: Contact Person: Dr. Shumana Zakaullah Email: shumanazakaullah@gmail.com Address: Department of Physical Therapy, Gujranwala Institute of Medical and Emerging Sciences (GIMES), Ali Pur Chatha Road, near Gujranwala Medical College, Gujranwala, Punjab, 52250, Pakistan

Applicants must submit a written request via email to the corresponding author, including a detailed research proposal, ethical approval letter, and signed data sharing agreement. Requests will be reviewed within 4–6 weeks. Approved applicants will receive deidentified data via secure encrypted file transfer.

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