The shortening of these muscles is usually due to gripping of the toes on the floor or wearing certain footwear. The toes grip down to stabilise the foot, as a result, the small joints of the toe are put under excess strain and begin to deform.
Curly toes are often asymptomatic but in the long term can cause problems such as limiting footwear choices as a wider toe box is necessary to accommodate this deformity. If ill-fitting footwear like tight-fitting shoes are worn, excess pressure on the toe may lead to callus, corns or blisters developing. If the situation deteriorates, the integrity of the nail may be affected. This eventually can lead to deformity of the nail and an increased risk of fungal or other infections developing.