A flexor hallicus longus (FHL) tendon transfer to the proximal phalanx of the big toe is used to treat clawing of the big toe.

Small muscles in the foot help to stabilize the big toe. When those muscles are weakened by disease, an imbalance occurs that leads to clawing. The clawing puts abnormal pressure on the ball of the foot that can cause an ulcer to form. In addition, clawing may lead to pressure on top of the toe from shoes. Clawing is associated with a variety of underlying disorders, including Charcot-Marie-Tooth disease, diabetic neuropathy, traumatic brain injury, polio, and stroke.

The primary goal of an FHL tendon transfer is to decrease the abnormal pressures on the big toe. This will prevent ulcer formation, or in the case of an existing ulcer, promote healing. An FHL tendon transfer often is done at the same time as other foot procedures.