Equinus is a condition in which the ankle joint range of motion is limited in an upward direction. Someone with equinus lacks the flexibility to bring the top of the foot toward the front of the leg. It can occur in one or both feet.
People with equinus develop compensation for their limited ankle motion and this can lead to other foot, leg and back problems. The most common methods of compensation are flattening of the arch or picking up the heel early when walking, placing increased pressure on the ball of the foot or by “toe walking”. This is the most common cause of the pediatric flat foot deformity. As the child’s weight increases, the tight calf muscle forces the foot to break down.
There are several possible causes for the limited range of ankle motion. Often it is due to tightness in the Achilles tendon or calf muscle. In most patients, the tightness is congenital and is therefore an inherited trait. Other patients acquire the tightness through situations that keep the foot pointing downward for extended periods of time such as a cast or wearing high-heeled shoes. In addition, diabetes can affect the fibers of the Achilles tendon and cause tightness.
To diagnose equinus, one of our podiatric physicians will evaluate the ankle’s range of motion. X-rays or a CT scan may be ordered. In some cases, the patient may be referred for neurologic evaluation.