Abstract
BACKGROUND: Joint bleeds for persons with hemophilia are characteristic and can lead to hemophilic arthropathy, primarily in the ankles, knees, and elbows. The Hemophilia Joint Health Score (HJHS) is a validated physical exam measure of hemophilic arthropathy but does not take into account functional range of motion (ROM). OBJECTIVES: To examine the association between HJHS severity and functional ROM during simulated sports activities in persons with hemophilia compared with healthy controls. METHODS: Using motion capture analysis, functional ROM at the ankle, knee, and hip was measured in 86 persons with hemophilia A or B and 33 healthy controls while performing 10 simulated sports activities. Comparisons of functional ROM were made across 5 groups (1 control and 4 hemophilia groups based on total 6-joint HJHS) using Jonckheere-Terpstra and Kolmogorov-Smirnov post hoc analyses. RESULTS: Persons with hemophilia who had a total 6-joint HJHS ≥25 demonstrated reduced functional ROM compared with controls, most notably at the ankle, where significant reductions were observed in 8 of 10 activities. Persons with hemophilia who had a total 6-joint HJHS <25 showed functional ROM similar to controls, with no significant reductions in any joint during any activity. CONCLUSION: Decreased functional ROM in persons with hemophilia, with a 6-joint HJHS ≥25, represents a threshold for significantly diminished movement capacity. Further understanding the relationship between HJHS and functional ROM can support earlier identification of mobility limitations, inform targeted rehabilitation, and guide interventions to preserve activity in persons with hemophilia.