The feasibility of a novel exercise therapy and activity modification intervention for patients with Sever’s disease

Sever’s disease (calcaneal apophysitis) is a common cause of heel pain in physically active youth. Evidence-based treatment options are limited, with no consensus for the standard of care. This study aimed to assess the feasibility of delivering an intervention comprising exercise therapy and pain-guided activity modification for youth patients with Sever’s disease and to describe patient symptoms, functional limitations, psychosocial factors, and ultrasound imaging findings to inform future clinical trials. This single-cohort study enrolled patients between 7 and 17 years old with Sever’s disease. Participants received a comprehensive 12-week intervention combining daily Achilles-tendon loading exercises, activity modification using a pain-monitoring model, and patient education. Training diaries were provided to monitor adherence, daily activities, and pain. Feasibility was assessed via recruitment and retention rates, daily activity modification adherence, rehabilitation adherence, and safety. Secondary outcomes (patient-reported outcome measures, functional test battery, and ultrasound imaging) were collected at baseline and at 4-, 8-, and 12 weeks and were reported descriptively to characterize the biopsychosocial burden of the condition and inform selection of outcomes and hypotheses for future clinical trials. Of the 13 participants enrolled (7F/6 M, (mean ± SD) age 11.5 ± 2.5 years, BMI 21.6 ± 4.6 kg/m 2 ), recruitment and retention rate was 65% and 69%, respectively. Activity modification adherence was 91 ± 28% (range 37–100%), and rehabilitation adherence was 91 ± 25% (range 25–100%). Three adverse events occurred and each was unrelated to participation. All participants expressed satisfaction with the intervention (75% [10/10] very satisfied). Our findings support that this exercise therapy and activity modification intervention is feasible, safe, and appropriate for the treatment of Sever’s disease. Intervention satisfaction ratings and favorable global rating of change scores reported imply that educating patients to use a pain-monitoring model, allowing for modified physical activity, is not detrimental to patients with Sever’s disease. A larger randomized controlled trial is warranted to evaluate the effectiveness of this intervention. ClinicalTrials.gov Identifier: NCT04816188. Registered 18th of March, 2021 retrospectively.