Comparison of Braces for Treatment of Sever's Disease in Barefoot Athletes
Phase: NA
Conditions: Sever's Disease
Sponsor: University of Colorado, Denver

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COMIRB Protocol 
COLORADO MULTIPLE INSTITUTIONAL REVIEW BOARD 
CAMPUS BOX F-490    TELEPHONE:  303-724-1055  Fax:  303-724-0990 
 
 
 
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Protocol #: 17-0611 
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Project Title: Comparison of braces for treatment of Sever’s disease 
 
 
 
 
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Principal Investigator:  Emily Sweeney, MD 
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Version Date: 
03/25/2020 
 
 
 
 
 
  
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I. Hypotheses and Specific Aims:   
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Primary Aim: To compare two types of braces: The X Brace (The X Brace, Grand Rapids, MI) and 
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Cheetah Heel Cups (Tuli’s®, Medi-Dyne, Colleyville, TX), in pain reduction for barefoot athletes (e.g. 
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karate, gymnasts, dancers) diagnosed with Sever's disease (calcaneal apophysitis) 
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Hypothesis 1 – The Cheetah Heel Cup will be significantly more effective than The X Brace 
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in reducing pain for barefoot athletes diagnosed with Sever’s disease, demonstrated by a 
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mean score difference greater than the minimal detectable difference (7 points) on the 
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OxAFQ-C in the physical domain.  
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II. Background and Significance:  
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Sever’s disease is an osteochondrosis of the calcaneal apophysis due to frequent repetitive foot 
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impact and repeated traction from the Achilles tendon, which attaches to the apophysis.1 Though 
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there remains uncertainty about the exact pathomechanics of this ailment, it is generally 
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considered an overuse injury affecting active skeletally-immature children aged 8-14 years.2 
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Identified risk factors include high levels of athletic activity,3 increased BMI,4,5 and anthropometric 
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differences compared to a normative peer group including increased weight, height, ankle range of 
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motion, waist circumference, and foot posture index.5  A recent, large cross-sectional study 
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examining visits to primary care practices reported an incidence of 3.7 per 1,000 patients ages 6-17 
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with a median age of 10 years for girls and 12 years for boys.6 One systematic review reports that 
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Sever’s accounts for 2%-16% of musculoskeletal complaints in children.7 This condition, which 
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presents as heel pain with physical activity, is one of the most common pathological entities among 
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this age group and a serious concern for growing athletes.6  
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Sever’s disease has real and tangible effects on quality of life.2 Children with this condition report 
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greater pain and discomfort, dissatisfaction with their symptoms, and less happiness than 
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asymptomatic peers.2 It is also suggested that children may postpone treatment as they have the 
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“ability and the competitive motivation to endure the pain… for an extended period of time,” 
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which can delay healing and prolong pain. Even despite that the pain associated with Sever’s is 
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often so severe that the child will limp to relieve pressure on the affected heel during or after 
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physical activity.3,8,9  
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It is widely accepted and scientifically confirmed that physical activity improves child health with 
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positive effects on adiposity, musculoskeletal health and fitness, and cardiovascular health.10 
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Beyond the health benefits of physical activity alone, participation in sports at this crucial age 
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enhances psychological and social health outcomes.11 Athletes with Sever’s symptoms are limited 
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in their ability to participate in physical activity and athletics, and it is suggested that active 
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intervention in the management of Sever’s is most appropriate to improve quality of life and 
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outcomes without substantial time lost from sport or physical activity.2 Therefore, efficient and 
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effective treatment is essential, especially for active and competitive athletes.  
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Standard treatment for Sever’s disease is placement of heel cups in shoes and stretching or 
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physical therapy. These interventions are effective in reducing Sever’s patients’ heel pain.12-16 A 
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retrospective study showed that with treatment with a heel cup or other foot orthoses, symptoms 
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improved within 2 months.8 However, there remains a distinct lack of randomized control trials 
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evaluating treatments for Sever’s in the literature.17 For the many young athletes with Sever’s who 
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participate in barefoot sports such as gymnastics, dance, or tae kwan do, the standard treatment is 
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inadequate. They cannot use the recommended heel cups, which are placed in an athletic shoe. 
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Currently, two braces are commonly used for barefoot athletes with Sever’s: Cheetah Heel Cups 
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and The X Brace. Neither of these braces are currently FDA approved as they are not considered 
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medical devices and are marketed as an insert. Health care providers often recommend barefoot 
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athletes purchase these braces, but no published studies evaluating their effectiveness exist in the 
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established literature. This study will compare these two braces in an investigator-blinded, 
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randomized control trial in order to contribute to the understanding of standard treatment for 
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barefoot athletes with Sever’s disease and improve patient outcomes by affecting clinical practice. 
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In light of the paucity of information on and the importance of optimizing patient outcomes to 
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improve quality of life and maintain an active lifestyle for young barefoot athletes, this prospective, 
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randomized treatment study will compare the effectiveness of two braces in decreasing pain 
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severity in barefoot athletes diagnosed with Sever’s disease. 
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III. Preliminary Studies/Progress Report:   
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No preliminary studies have been conducted at this institution. 
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IV. Research Methods 
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A. Outcome Measures:   
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i. 
Primary Outcome: Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) Scores 
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ii. 
Visual Analog Scale (VAS) Pain Score 
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iii. 
Subject-Reported Compliance with Brace Use 
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1. Hours per week the brace was worn with barefoot sport activity 
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iv. 
Rest from Sport 
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1. Amount of time per week taken off from barefoot sport due to pain (if 
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applicable) 
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v. 
Acceptability of Brace  
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1. Comfort (Comfortable: Y/N) 
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2. Appearance (Acceptability: Y/N) 
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3. Perceived Effect on Athletic Performance (Improvement: Y/N) 
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vi. 
Pain Medicine Usage 
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1. Weekly dosage of pain medicine (if applicable) 
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B. Explanatory Variables: 
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i. 
Demographic 
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1. Name and Medical Record Number 
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2. Date of Birth 
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3. Age at time of visit 
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4. Gender 
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5. Ethnicity 
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6. Weight 
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7. Height 
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8. BMI 
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9. Athletic participation 
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10. Primary sport 
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11. Hours per week in a barefoot sport 
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ii. 
History 
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1. Previous diagnosis of Sever’s or calcaneal apophysitis 
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a. Brace previously used 
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Figure 1. Cheetah Brace  
 
 
Figure 2. The X Brace 
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C. Description of Population to be Enrolled:   
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Barefoot athletes who present to sports medicine clinic for foot, ankle, or heel pain. 
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i. 
Inclusion Criteria: 
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1. Aged 7-14 years 
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2. Participate in barefoot sports including: martial arts, dance, gymnastics, or 
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acrobatics 
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3. A clinical diagnosis of Sever's or calcaneal apophysitis 
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ii. 
Exclusion Criteria: 
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1. History of foot/ankle surgery 
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2. History of rheumatologic diagnoses 
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3. Prisoners, pregnant females, individuals with limited decision-making capacity 
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D. Study Design and Research Methods   
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i. 
Human Subject Considerations 
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1. All patients will have an established relationship with a Children’s Hospital 
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Sports Medicine Physician. 
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2. All PHI will be stored within REDCap. 
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ii. 
Study Design: Randomized Treatment Study 
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iii. 
Methods: 
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1. Subjects will be recruited face-to-face by a study team member at time of initial 
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visit, diagnostic clinical visit, or phone call initiated by Dr. Sweeney. Subjects 
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recruited via phone call will be patients of study personnel. Patients and 
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families interested in participating in the study will be contacted by a member 
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of the study team to set up a research only consent visit. If they cannot come 
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into clinic, the informed consent and assent will be sent to the family and a 
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research assistant with call the family, either via phone or video call, to go over 
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the consent and assent in real time and to answer any questions. After a signed 
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consent or assent form is received by the research assistant, the assigned brace 
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will be sent in the mail to the family and the associated questionnaires will be 
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sent via email. 
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2. Subject will be screened for inclusion/exclusion (enrollment) criteria by study 
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team member through chart review. 
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3. If subject meets enrollment criteria, they and a legal guardian will be consented 
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face-to-face by a study team member. 
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a. Consent will be sought from subjects ages 13-14. 
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b. Assent will be sought from athletes younger than 13 years of age. 
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c. Consent will be sought from parents of subjects ages 7-14. 
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4. Dr. Sweeney or designated staff will answer any questions after the patient and 
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his or her parents have read and reviewed the informed consent and assent 
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forms. It will be emphasized to the patients that their decision to participate in 
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the study will in no way impact their treatment.  Comprehension will be 
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assessed by reviewing the consent forms with the patient and his or her parents 
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thoroughly and asking the subjects questions requiring more than a simple 
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yes/no answer. 
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a. Patients and parents will sign the appropriate line on the informed 
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consent/assent form. 
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b. Consent procedures will take place in a private room or over a private 
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call.  
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5. Subject will complete initial demographics survey, OxAFQ-C, and VAS. 
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6. Subject will be randomized into either the Cheetah Heel Cup or The X Brace 
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treatment group. The randomization scheme will be independently created by 
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the research assistant. The random assignment will be kept blind to the PI and 
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statistician.  
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7. Subject will receive their assigned brace in the mail following their consent visit. 
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Subjects will receive an activity and rest log in the mail with their 
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brace. This is a weekly log and will help subjects track their weekly 
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activity in their barefoot sport (in hours), amount of time spent in 
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brace during barefoot sport (in hours), and any rest time taken from 
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their barefoot sport (in hours). This log is optional, but encouraged, 
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to fill out as it will not be submitted to the researchers. The 
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intended purpose of the log is to aid in answering the monthly 
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questionnaire on weekly activity, time in brace, and rest time.   
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8. At 1, 2, and 3 months, a study team member will email the subject’s parent the 
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OxAFQ-C, VAS and questionnaire on activity/brace usage. During this time, 
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subjects will also answer questions pertaining to pain medicine use and any 
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adverse outcomes from brace use.  A reminder phone call will be made if the 
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questionnaires have not been completed within 5 days. Subjects will not be 
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seen after the visit where consent was obtained, unless an adverse outcome 
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arises requiring an assessment by Dr. Sweeney. 
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iv. 
Planned Duration of Study 
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1. Two-years from COMIRB approval date to allow for adequate enrollment 
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v. 
Duration of Participation of Each Subject 
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1. About 30 active minutes for consent and surveys 
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2. About 3 months for course of clinical care and resolution of symptoms 
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vi. 
Patient Incentives 
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1. Participants will receive a free brace after enrolling into the study. Upon 
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successful completion of the study (once month 3 survey is 
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completed), subjects will receive a $30 gift card in the mail. 
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E. Description, Risks and Justification of Procedures and Data Collection Tools: 
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i. 
Potential Risks to Subjects:  
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There are no anticipated risks in this study beyond those of standard care and daily 
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living. There are no documented adverse outcomes associated with either brace 
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that is known to the study team. Any adverse outcomes (skin irritation/rash) that 
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arises during the study period will be documented during the monthly 
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questionnaires sent out to subjects. Additionally, an unlikely and uncommon risk of 
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this study is that PHI may be unintentionally disclosed to an outside party. We will 
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put forth our best effort to keep the information about subjects secure, and we 
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believe that the risk of accidental disclosure is minute. Identifying data will be 
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protected as per REDCap protocol after subjects have been assigned a study 
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number. 
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ii. 
Plan to Protect Subjects/Mitigate Risks: 
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Subjects will be instructed to call the research assistant if any adverse outcomes 
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arise (skin irritiation/rash that causes discomfort or concern). The research 
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assistant will document the adverse outcome in REDCap, and relay the message 
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onto Dr. Sweeney who will contact the family to discuss the adverse event and if 
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any of the following is needed: a new brace size, discontinued use of the 
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brace/removal from study, a research visit to assess the adverse reaction. A 
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REDCap database will be utilized for the organization and storage of patient 
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information when necessary.  Patients will be identified using individualized study 
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numbers that will be stored securely in the REDCap database.  Data containing 
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spreadsheets will refer to patients only by the individualized study numbers, 
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excluding all PHI. 
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iii. 
Participant Discontinuation Criteria: 
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1. Subject participation will be discontinued if: 
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a. Subject no longer wishes to participate in the study 
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b. Subject sustains an additional musculoskeletal injury or serious illness 
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(hospitalization, injury to lower body requiring a visit to 
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doctor). 
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c. Subject fails to follow-up with clinical care. 
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d. Adverse reaction causing Dr. Sweeney to determine a discontinuation of 
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the brace. 
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iv. 
Data Collection Tools: 
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1. Demographic and clinical data will be collected from the subjects’ charts from 
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EPIC and through subject input to REDCap questionnaires. REDCap will be used 
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to store all study data electronically. REDCap is a secure, web application 
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designed to support data capture for research studies. REDCap is hosted by the 
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University of Colorado-Denver Development and Informatics Service Center 
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(DISC). 
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2. The Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) is used to measure 
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subjective well-being for child patients (aged 5-16) affected by foot and ankle 
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conditions using issues that are considered important to children. Typical 
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clinical assessments fail to capture the child patient’s perspective and may not 
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accurately reflect how children function in their usual environments. The 
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OxAFQ-C was therefore designed to supplement clinical assessments to 
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evaluate the effectiveness of interventions for ankle/foot problems in children. 
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It is a short (15-item) questionnaire and reported as valid and reliable in 
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English18 and Spanish and as responsive and longitudinally valid19. There are 
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three domains to the OxAFQ-C: physical, school and play, and emotional well-
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being.  Scores on the OxAFQ-C range from 0 to 100 with higher scores 
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indicating better functioning and higher well-being.  
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v. 
Data Management: 
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1. Patients will be assigned patient study identifiers. These identifiers will be used 
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for the identification of all study materials, and will only be linked to the 
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patient’s name, medical record number, or other PHI through REDCap. Non-
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identifiable data will be stored in Microsoft Excel, while PHI and any identifiable 
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information will be stored with Redcap. Redcap is a secure, web application 
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designed to support data capture for research studies, providing user-friendly 
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web-based case report forms, real-time data entry validation (e.g. for data 
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types and range checks), audit trails and a de-identified data export mechanism 
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to common statistical packages (SPSS, SAS, Stata, R/S-Plus). The system was 
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developed by a multi-institutional consortium which includes University of 
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Colorado-Denver and was initiated at Vanderbilt University. The database is 
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hosted at the University of Colorado-Denver Development and Informatics 
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Service Center (DISC), which will be used as a central location for data 
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processing and management. REDCap data collection projects rely on a 
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thorough study-specific data dictionary defined in an iterative self-documenting 
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process by all members of the research team with planning assistance from the 
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DISC. The iterative development and testing process results in a well-planned 
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data collection strategy for individual studies. Both REDCap and REDCap Survey 
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systems provide secure, web-based applications that are flexible enough to be 
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used for a variety of types of research, provide an intuitive interface for users to 
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enter data and have real time validation rules (with automated data type and 
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range checks) at the time of entry. These systems offer easy data manipulation 
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with audit trails and reporting for reporting, monitoring, and querying patient 
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records, and an automated export mechanism to common statistical packages 
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(SPSS, SAS, Stata, R/S-Plus).    
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vi. 
Potential Scientific Problems:   
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The investigators recognize no other potential scientific problems at this time. 
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F. Data Analysis Plan:   
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i. 
Sample Size: We will use a linear mixed model to test the null hypothesis that the 
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difference in OxAFQ-C physical domain scores between the The X Brace and 
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Cheetah Heel Cups does not depend on time (group*time interaction). Means for 
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treatment group at each time point were estimated based on a related RCT by 
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James et al. 13.   The common standard deviation for all OxAFQ-C physical domain 
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scores was assumed to be 6 and the correlation between time consecutive points 
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was conservatively assumed to be 0.6 based on this previous RCT. We intend to 
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use a one-to-one block randomization scheme to ensure equal allocation of 
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patients to each treatment group. Assuming a Type 1 error rate of 0.05, a sample 
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size of 44 participants total, 22 in each group, will provide 0.9 power to reject the 
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null hypothesis of no group*time interaction based on the Hotelling-Lawley test 
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statistic with an alpha level of 0.05. Assuming there is no missing data, no time 
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varying covariates, and the repeated measures are consistently collected (general 
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linear mixed model reversibility criteria is met),the Hotelling-Lawley trace statistic 
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is equivalent to the statistical test, the Wald statistic with Kenward-Roger degrees 
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of freedom, described in the data analysis plan.20 . With an expected 30% loss to 
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follow up, we will inflate the sample size to account for attrition, for a total 
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enrollment goal of 58. The clinic treats 10 barefoot athletes with a clinical 
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diagnosis of Sever’s Disease who meet the eligibility criteria for this study each 
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month. We expect a consent rate of approximately 50%. At an effective enrollment 
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rate of 5 patients per month, we will reach the enrollment goal of 58 participants 
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within 12 months. All samples size calculations were performed with GLIMMPSE, 
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an internet based open source software program capable of computing power and 
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sample size for multi-level and longitudinal research designs21 
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ii. 
Table 1. Expected OxAFQ-C physical domain scores based on data from James et 
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al13 
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Treatment 
1 month 
2 months 
3 months 
Cheetah Heel Cups 
67 (±6) 
83 (±6) 
85 (±6) 
The X Brace 
64 (±6) 
82 (±6) 
78 (±6) 
 
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iii. 
Analysis Plan: Demographic and clinical characteristics will be summarized and 
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compared between the two treatment groups using chi-squared and two-sample t-
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tests for categorical and continuous data, respectively. Imbalance between groups 
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will be adjusted for in subsequent statistical analyses. For hypothesis 1, Linear 
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mixed model regression analyses will be used to compare group differences 
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(Cheetah Brace vs X brace) across the 1, 2 and 3 month visits. We will test the null 
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hypothesis that the difference between groups does not depend on time 
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(group*time interaction). The parameter estimate will be tested using the Wald 
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statistic with Kenward-Roger degrees of freedom and an alpha level of 0.05. 
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Intent-to-treat analyses will be performed for all the primary outcome variables. A 
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per-protocol analysis will also be performed.  For the secondary analysis, the other 
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two domains of the OxAFQ-C questionnaire as well as VAS pain scores will be 
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analyzed using separate linear mixed models that iwill also test the group*time 
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interaction. Linear regression models will also be used to compare overall 
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compliance. Logistic regression models will be used to test the null hypothesis of 
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no difference between groups for each of the three brace acceptability metrics 
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(comfort, appearance, and perceived effect on athletic performance). 
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G.  Summarize Knowledge to be Gained:   
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It is common practice to provide heel cups and stretching exercises for patients with 
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Sever's.  Because these heel cups cannot be used in barefoot athletes, alternative braces 
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are used.  Currently, there are two commonly used braces in barefoot athletes, Cheetah 
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Heel Cups and the The X Brace.  No previous study has looked at the effectiveness of these 
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braces.  This study would compare these braces in a blinded clinical trial to determine if 
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these braces are effective and if one brace is more effective in decreasing severity of pain 
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in barefoot athletes with Sever's. This study will contribute to the understanding of 
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treatment for barefoot athletes with Sever’s disease and will improve patient outcomes by 
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affecting clinical practice.  In order to improve quality of life and allow young athletes to 
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remain active, this prospective, randomized treatment study will compare the 
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effectiveness of two braces in decreasing pain severity in barefoot athletes diagnosed with 
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Sever’s disease.   
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 H. References: 
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1. 
Launay F. Sports-related overuse injuries in children. Orthopaedics & traumatology, 
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surgery & research : OTSR. 2015;101(1 Suppl):S139-147. 
352 
2. 
Scharfbillig RW, Jones S, Scutter S. Sever's disease--does it effect quality of life? Foot 
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(Edinb). 2009;19(1):36-43. 
354 
3. 
McKenzie DC, Taunton JE, Clement DB, Smart GW, McNicol KL. Calcaneal epiphysitis in 
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adolescent athletes. Can J Appl Sport Sci. 1981;6(3):123-125. 
356 
4. 
Scharfbillig RW, Jones S, Scutter S. Sever's disease: a prospective study of risk factors. J 
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Am Podiatr Med Assoc. 2011;101(2):133-145. 
358 
5. 
James AM, Williams CM, Luscombe M, Hunter R, Haines TP. Factors Associated with Pain 
359 
Severity 
in 
Children 
with Calcaneal 
Apophysitis 
(Sever 
Disease). 
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Pediatr. 
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2015;167(2):455-459. 
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6. 
Wiegerinck JI, Yntema C, Brouwer HJ, Struijs PA. Incidence of calcaneal apophysitis in the 
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general population. Eur J Pediatr. 2014;173(5):677-679. 
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7. 
Scharfbillig RW, Jones S, Scutter SD. Sever's disease: what does the literature really tell 
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us? J Am Podiat Med Assoc. 2008;98. 
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8. 
Micheli LJ, Ireland ML. Prevention and management of calcaneal apophysitis in children: 
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an overuse syndrome. J Pediatr Orthop. 1987;7(1):34-38. 
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9. 
Micheli LJ, Fehlandt AF. Overuse injuries to tendons and apophyses in children and 
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adolescents. Clin Sport Med. 1992;11. 
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10. 
Janssen I, LeBlanc AG. Systematic review of the health benefits of physical activity and 
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fitness in school-aged children and youth. International Journal of Behavioral Nutrition and 
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Physical Activity. 2010;7(1):40. 
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11. 
Eime RM, Young JA, Harvey JT, Charity MJ, Payne WR. A systematic review of the 
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psychological and social benefits of participation in sport for children and adolescents: 
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informing development of a conceptual model of health through sport. International Journal 
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of Behavioral Nutrition and Physical Activity. 2013;10(1):98. 
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12. 
James AM, Williams CM, Haines TP. "Effectiveness of interventions in reducing pain and 
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maintaining physical activity in children and adolescents with calcaneal apophysitis 
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(Sever's disease): a systematic review". J Foot Ankle Res. 2013;6(1):16. 
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13. 
James AM, Williams CM, Haines TP. Effectiveness of footwear and foot orthoses for 
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calcaneal apophysitis: a 12-month factorial randomised trial. Br J Sports Med. 
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2016;50(20):1268-1275. 
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14. 
Perhamre S, Lundin F, Klassbo M, Norlin R. A heel cup improves the function of the heel 
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pad in Sever's injury: effects on heel pad thickness, peak pressure and pain. Scand J Med 
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Sci Sports. 2012;22(4):516-522. 
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15. 
Perhamre S, Lundin F, Norlin R, Klassbo M. Sever's injury; treat it with a heel cup: a 
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randomized, crossover study with two insole alternatives. Scand J Med Sci Sports. 
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2011;21(6):e42-47. 
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16. 
Wiegerinck JI, Zwiers R, Sierevelt IN, van Weert HC, van Dijk CN, Struijs PA. Treatment of 
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Calcaneal Apophysitis: Wait and See Versus Orthotic Device Versus Physical Therapy: A 
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Pragmatic Therapeutic Randomized Clinical Trial. J Pediatr Orthop. 2016;36(2):152-157. 
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17. 
James AM, Williams CM, Haines TP. Heel raises versus prefabricated orthoses in the 
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treatment of posterior heel pain associated with calcaneal apophysitis (Sever's Disease): 
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study protocol for a randomised controlled trial. Journal of Foot and Ankle Research. 
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2010;3(1):3. 
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18. 
Morris C, Doll HA, Wainwright A, Theologis T, Fitzpatrick R. The Oxford ankle foot 
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questionnaire for children: scaling, reliability and validity. J Bone Joint Surg Br. 
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2008;90(11):1451-1456. 
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19. 
Morris C, Doll H, Davies N, et al. The Oxford Ankle Foot Questionnaire for children: 
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responsiveness and longitudinal validity. Qual Life Res. 2009;18(10):1367-1376. 
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20. 
Muller KE, Edwards LJ, Simpson SL, Taylor DJ. Statistical tests with accurate size and 
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power for balanced linear mixed models. Statistics in medicine. 2007;26(19):3639-3660. 
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21. 
Kreidler SM, Muller KE, Grunwald GK, et al.: Online Power Computation for Linear Models 
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with and without a Baseline Covariate. Journal of statistical software. 2013;54(10). 
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