Table 1 Inclusion and exclusion criteria

Boys with mild, moderate and severe haemophilia type A or B.

Age 6–15 years.

Inhibitor or non-inhibitor.

Able to follow simple verbal instructions and provide informed consent.

History of: fracture or trauma to the lower limb; orthopaedic surgery of the lower limb;

Acquired brain injury; or any other disturbance of the central nervous system.

Joint or muscle bleed in the lower limb in the past 6 weeks.

Lower limb pain (assessed prior to testing).

Unable to follow verbal instructions.

Diagnosis of uncontrolled severe asthma, exercise induced bronchoconstriction or other medical conditions.