Fractures of the fifth metatarsal are common in dancers, and can occur when the dancer rolls the foot into inversion. There are a few different exercises that are important to perform in order to prevent a fracture, or rehabilitate after the fracture.
These exercises will assist with achieving the closed packed position of the lateral column of the foot, and assist with the push-off phase of gait. The closed packed position of the lateral foot is in the terminal stance phase of gait, or during a plié. Many dancers sustain fifth metatarsal fractures when landing a jump, or in terminal stance where the lateral foot should reach a closed packed position, but it doesn’t. (Left: Picture of a plie, Below: Picture of terminal stance)
First, the extensor digitorum brevis (EDB) must be strong in order to maintain a healthy position of the cuboid bone, which is part of the lateral column of the foot. The EDB assists in the dorsal pull of the cuboid on the calcaneus to reach the closed packed position. Ultimately, the proper movement of the calcaneocuboid joint keeps the fifth metatarsal in an optimal position during plié. Second, the extensor digitirum longus (EDL) must be re educated in order to assist with fifth toe dorsiflexion. It is the only muscle that can lift our 5th toe. To exercise both the EDB and EDL, perform toe dorsiflexion with the ankle flexed and pointed, as shown below:
Finally, the peroneus longus must assist with plantar flexion of the first ray during the push off phase of gait. If the peroneus longus cannot keep the first metatarsal on the ground in terminal stance or gait or during a plié, there will be an increased load though the lateral side of the foot with an increased inversion moment that may cause the patient to roll the foot and potentially fracture. Below is a picture of the push off phase of gait, as well as the activation of the peroneus longus. Remember that the muscle belly of the peroneus longus is on the lateral side of the leg, and you should see the muscle contract as the patient presses the first metatarsal down into the floor.
There are many interventions that can be used to help prevent or rehabilitate a 5th metatarsal fracture, and these are just a few. These are small, important muscles of the foot, and the exercises may be difficult to perform. Be sure to assist your dancer with the proper technique for success!