Background
Regular physiotherapy with a physiotherapist experienced in the field is not feasible for many patients with haemophilia. We, therefore, developed a blended physiotherapy intervention for persons with haemophilic arthropathy (HA) (e-Exercise HA), integrating face-to-face physiotherapy with a smartphone application.

Aim
The aim of the study was to determine proof of concept of e- Exercise HA and to evaluate feasibility.

Methods
Proof of concept was evaluated by a single-case multiple baseline design. Physical activity (PA) was measured with an accelerometer during a baseline, intervention and post-intervention phase and analysed using visual inspection and a single case randomisation test. Changes in limitations in activities (Haemophilia Activities List [HAL]) and a General Perceived Effect (GPE) were evaluated between baseline (T0), post-intervention (T1) and 3 months post-intervention (T2) using Wilcoxson signed rank test. Feasibility was evaluated by the number of adverse events, attended sessions and open-ended questions.

Results
Nine patients with HA (90% severe, median age 57.5 (quartiles 50.5–63.3) and median HJHS 32 (quartiles 22–36)) were included. PA increased in two patients. HAL increased mean 15 (SD 9) points (p = .001) at T1, and decrease to mean +8 points (SD 7) (p = .012) at T2 compared to T0. At T1 and T2 8/9 participants scored a GPE > 3. Median 5 (range 4–7) face-to-face sessions were attended and a median 8 out of 12 information modules were viewed. No intervention-related bleeds were reported.

Conclusion
A blended physiotherapy intervention is feasible for persons with HA and the first indication of the effectiveness of the intervention in decreasing limitations in activities was observed.