Red flag

Explanation

1) A combination of severe pain in the groin, motor and sensory loss in femoral nerve distribution, and flexed hip and knee (the “psoas sign”) could indicate an iliopsoas injury or bleed [18] .

When distinguishing between hip hemarthroses and iliopsoas bleeds, the former cause pain with passive and active motion in any direction, and limited ROM; the latter present with pain in the groin on active hip flexion or active and passive hip extension, but less painful passive flexion [7] [18] [71] . An individual with hemophilia with a hemarthrosis or muscle bleed should be referred back to their HTC. However, the psoas sign should be treated as a medical emergency, as psoas bleeds may be

life-threatening if not urgently treated with clotting factor replacement [18] [71] .

2) Proprioceptive exercises may lead to bleeding if conducted too early after a hemarthrosis or in the presence of chronic synovitis. Appropriate care should be taken.

These exercises are advanced, typically involving minor corrective movements and rotation in combination with weight bearing. They have a tendency to mechanically pinch a swollen, hypertrophied, highly vascular synovium, which can precipitate a hemarthrosis.

3) Traditional posture exercises with end-range positions (such as aggressive stretching of fibrosed joints) should be avoided, as these exercises could aggravate arthropathy or generate new bleeds in joints or soft tissue.

Hard end-feels and bony blocks can indicate arthropathy; in the presence of these signs, aggressive traditional exercises should be avoided. PWH may want to train on their own at home or at a fitness center without seeking guidance on appropriate muscle strength exercises from PTs. In these circumstances, it should be emphasized that

end-range position exercises may cause hemarthroses and be detrimental to their joint health. The focus of physical therapy exercises should instead be on supportive strategies and within the available ROM in those with severe joint disease.

4) PTs must stretch chronic joint flexion contractures with caution.

Stretching of any contracture (see Figure 5) in PWH should be undertaken with a high degree of caution and extremely slowly; acute contractures should be referred immediately to the HTC. This is very different from the approach used in the general population, where stretching is encouraged. Aggressive joint mobilization and high-velocity manipulations can cause a hemarthrosis and may be contraindicated.

5) New or acute pain may indicate a new hemarthrosis or bleed.

Sometimes PWH struggle to distinguish bleed pain from arthropathy flares from soreness experienced at the beginning of a new exercise regimen.

PTs can assess the joint to determine the cause of pain before proceeding with treatment or exercise recommendations.

6) PWH with inhibitors have a more complex form of hemophilia and their bleeding is more difficult to control; they should be managed only by PTs specialized in hemophilia at the HTC (where available).

Inhibitors are a serious complication of hemophilia, where PWH develop antibodies against the clotting factor, and bleeding and joint disease can be more severe than usual [23] [24] . In these people, infusions of factor concentrates typically do not control bleeding, which may instead be managed with bypassing agents or an antibody therapeutic [7] [24] . Individuals with inhibitors often have more lengthy and poorly controlled coagulation, and more joint damage at younger ages vs those without inhibitors [23] [24] [72] . PTs treating these patients should proceed with great care, with delicate physical assessment and a slow progression of interventions. Ideally, PWH with inhibitors should be treated by experienced PTs in an HTC, where they may receive immediate assessment and intervention from a hematologist or nurse if needed.