Equinus occurs when the Archilles tendon or calf muscles are too tight to allow upward bending motion of the ankle. The person would find it very difficult or impossible to bring the foot toward the shin.
People with equinus deformity often overcompensate this limitation of motion with the other foot, leg, back, hip or knee, causing problems in those areas. To ease movements, many of them flatten the arch of the foot when walking, placing their body weight on the ball of the foot or toes instead and causing pain and callusing. Others use the support of their hips or knees, resulting in an unusual walking stance.
The tightness in the Archilles tendon or calf muscles may be inherited from parents or the person is born with shorter Archilles tendon. Having a cast on for a long period of time or wearing inappropriate footwear such as heels, could also cause the stiffness. If the foot suffered a serious ankle injury before, there could be a broken bone blocking the joint, thereby restricting motion.
This deformity could also be a symptom of a more serious condition. Diabetes causes many foot problems, including tightening of the Archilles tendon. If spasms are felt in the calf, it could be a sign of a neuromuscular disease.
To find out the cause of equinus, the doctor would move the ankle when the knee is bent and straightened to assess if the tightness is from a tendon, muscle or bone block. X-ray may be used for further evaluation. If a neurologic disorder is suspected, the patient is referred to a specialist.
The cause of the condition is most important in determining the course of treatment, which could be surgical or non-surgical.
To relieve the symptoms of equinus, the patient might have to use heel lifts and/or custom orthotic devices in their shoes for better support, weight distribution and reduce pressure in the Archilles tendon. If the stiffness is from the calf muscles, a night splint is used to hold the foot in place during sleep. Physical therapy may be recommended to exercise the muscles and reduce tightness.
Surgery is opted for when the patient does not show significant improvement with non-surgical treatment or when the condition is too severe. The Archilles tendon can be surgically lengthened to reduce the tightness and gastroc recession is used to correct a portion of muscle. If the problem is a bone block, the fragment of broken bone impeding the joint motion is surgically removed.