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Updated: Nov 6, 2025

Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy
Published on: January 12, 2019
Feasibility, safety and acceptability of select outcome measures in a physiotherapy study protocol for boys with
Nicola Thorpe1, Phillip Harniess2, Eleanor Main3
1Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK. nicola.thorpe@gosh.nhs.uk.
Insights
This study found that high-level physical performance tests, including the iSTEP and 10-meter incremental shuttle walk test (10-m ISWT), are feasible, safe, and acceptable for children and young people with haemophilia (CYPwH). These measures can be incorporated into routine clinic appointments.
Area of Science:
- Pediatric Hematology
- Sports Medicine
- Rehabilitation Science
Background:
- Lack of functional performance measures and control data for children and young people with haemophilia (CYPwH).
- Need for more challenging measures to monitor physical performance in CYPwH due to improved medical treatments.
- Existing practical and safety concerns limit routine performance testing in CYPwH.
Purpose of the Study:
- To evaluate the feasibility, safety, and acceptability of select outcome measures for CYPwH.
- To assess the 10-meter incremental shuttle walk test (10-m ISWT), iSTEP (incremental step test), and accelerometry-wear.
- To compare performance data with typically developing boys (TDB).
Main Methods:
- Study involved 66 boys aged 6-15 years with haemophilia A or B.
- Measures included myometry, 10-m ISWT, iSTEP, and 1-week accelerometry.
- Feasibility, safety, and acceptability assessed via recruitment/retention rates, protocol completion, and absence of serious adverse events/reactions (SAE/SARs).
Main Results:
- 43 boys completed testing within a 10-month period (Jan-Nov 2018).
- High retention rate of 95% at protocol completion.
- No SAE/SARs were reported during the testing period.
Conclusions:
- The study protocol is feasible, safe, and acceptable for CYPwH.
- The iSTEP and 10-m ISWT are suitable, safe, and acceptable outcome measures for CYPwH.
- Further investigation into the psychometric properties of iSTEP is warranted for standardized use.
Background:
There is a lack of functional performance measures for children and young people with haemophilia (CYPwH) with associated control data from typically developing boys (TDB). The literature advocates development of a core set of outcome measures for different chronic conditions. As medical treatment improves, CYPwH are experiencing better outcomes; therefore, more challenging measures are required to monitor physical performance. Such testing is not performed routinely, due to practical and safety concerns.
Aim:
Evaluate the feasibility, safety and acceptability of select outcome measures as part of a study protocol testing CYPwH; including myometry, 10 metre incremental shuttle walk test (10-m ISWT), iSTEP (an incremental step test, with data from TDB), and 1 week of accelerometry-wear at home.
Methods:
Sixty-six boys aged 6-15 years with mild, moderate or severe haemophilia A or B (including inhibitors) attending routine clinics at Great Ormond Street Hospital were approached to participate. Descriptive statistics and content analysis were used to assess outcomes of feasibility, safety and acceptability, which included recruitment/retention rates, protocol completion within routine appointment timeframes, performance testing without serious adverse events/reactions (SAE/SARs), and acceptability to CYPwH of high-level performance measures.
Results:
Outcomes were met: 43 boys completed testing at clinic review (Jan-Nov 2018) within a 10-month timeframe, retention was 95% at completion of protocol and no SAE/SARs were reported throughout testing.
Conclusion:
Feasibility, safety and acceptability of the study protocol have been established in this population. Both high-level performance tests, iSTEP and 10-m ISWT, were an acceptable addition to boys' routine clinic appointments and could be safe, acceptable choices of outcome measure as part of a core set of tests for CYPwH. Further investigation of the psychometric properties for the iSTEP is now justified, in order for it to be used as a standardised, validated, reliable outcome measure in clinical or research settings.
Trial Registration:
Retrospectively registered on September 3, 2019, on ClinicalTrials.gov (ID: NCT04076306 ).

