Equinus is arguably the most common deformity of the foot and ankle, that no one talks about. It is not only a contributing factor in a number of foot and ankle related pathologies, but also has an effect on other areas higher up in the body; the knees, hips, and back.
It is a condition in which the upward bending motion of the ankle joint is limited. Someone with equinus lacks the flexibility to bring the top of the foot toward the front of the leg. Equinus can occur in one, or both feet. When it involves both feet, the limitation of motion is sometimes worse in one foot, than in the other.
People with equinus develop ways to compensate for their limited ankle motion, and this is where it often leads to other foot, leg, or 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. Some persons compensate by toe walking, while a smaller number, take steps by bending abnormally at the hip or knee.
There are several possible causes for the limited range of ankle motion. Often it is due to tightness in the Achilles tendon or calf muscles (the soleus muscle and or gastrocnemius muscle). In some persons, this tightness is congenital (present at birth), and sometimes it is an inherited trait.
Other patients acquire the tightness from being in a cast, being on crutches, or frequently wearing high-heeled shoes. In addition, diabetes can affect the fibers of the Achilles tendon and cause tightness.
Sometimes the condition is related to a bone blocking the ankle motion. For example, a fragment of a broken bone following an ankle injury, or bone block, can get in the way and restrict motion. Equinus may also result from limb discrepancy (one leg being shorter than the other). Less often, it is caused by spasms in the calf muscle. These spasms may be signs of an underlying neurologic disorder.
Foot Problems Related to Equinus
Depending on how a patient compensates for the inability to bend properly at the ankle, a variety of foot conditions can develop, including:
- – Plantar fasciitis (arch/heel pain)
- – Posterior tibial dysfunction
- – Calf cramping
- – Tendonitis (inflammation in the Achilles tendon)
- – Metatarsalgia (pain and or callusing on the ball of the foot)
- – Flatfoot
- – Arthritis of the midfoot
- – Pressure sores on the ball of the foot or the arch
- – Bunions
- – Hammertoes
- – Ankle pain
- – Shin splints
Most patients with equinus are unaware they have this condition when they first visit the doctor. Instead, they come to the doctor seeking relief for foot problems associated with equinus.
To diagnose equinus, the orthopaedic surgeon or podiatrist will evaluate the ankle range of motion when the knee is flexed (bent), as well as extended (straightened). This enables the health professional to identify whether the tendon or muscle is tight, and to assess whether bone is interfering with ankle motion. X-rays may also be ordered. In some cases, the health professional may refer the patient for neurologic evaluation.
Treatment includes strategies aimed at relieving the associated symptoms and conditions. In addition, the patient is treated for the equinus itself through one or more of the following options:
- – Night splint – The foot may be placed in a splint at night, to keep it in a position that helps reduce tightness of the calf muscle.
- – Heel lifts – Placing heel lifts inside the shoes, or wearing shoes with a moderate heel, takes stress off the Achilles tendon when walking, and may reduce symptoms.
- – Arch supports or orthotic devices – Custom orthotic devices that fit into the shoe are often prescribed, to keep weight distributed properly, and to help control muscle/tendon imbalance.
- – Physical therapy – To help remedy muscle tightness, exercises that stretch the calf muscle(s) are recommended.
When is Surgery Needed?
In some cases, surgery may be needed to correct the cause of equinus if it is related to a tight tendon or a bone blocking the ankle motion. The orthopaedic surgeon will determine the type of procedure that is best suited to the individual patient.
Your feet mirror your general health . . . cherish them!