Equinus: The Common Denominator
The Common Denominator
Foot and Ankle Specialists see a vast variety of foot and ankle pathology. Dr. Sara Suttle and Dr. Paul Marciano are Foot and Ankle Surgeons in Southlake, TX. They treat everything from Bunions and Plantar Fasciitis, to Hammertoes and Achilles’ Tendinitis. But all of these conditions have something in common. Patients that suffer from each of these ailments, and many more, all have a Common Denominator: A tight Achilles’ tendon.
A tight Achilles’ tendon, or Equinus, is the root cause behind the majority of foot and ankle conditions. The ankle joint requires 10-15 degrees of flexion for normal ambulation. When a tight Achilles’ tendon limits this flexion, the foot has to flatten out to compensate for this lack of motion.
What is Equinus?

Equinus 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 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. Other patients compensate by "toe walking," while a smaller number take steps by bending abnormally at the hip or knee.
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)
• Calf cramping
• Tendonitis (inflammation in the Achilles tendon)
• Metatarsalgia (pain and/or callusing on the ball of the foot)
• Flatfoot
• Arthritis of the midfoot (middle area of the foot)
• Pressure sores on the ball of the foot or the arch
• Bunions and 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 foot and ankle surgeon will evaluate the ankle's range of motion when the knee is flexed (bent) as well as extended (straightened). This enables the surgeon 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 foot and ankle surgeon may refer the patient for neurologic evaluation.
Although treatment for each of the above-mentioned conditions is different, treating the underlying problem, the equinus, is always necessary. This can be done conservatively, by stretching and Physical Therapy or surgically, by different lengthening techniques.
This article will touch on a few of the most common foot and ankle ailments and how a tight Achilles’ tendon perpetuates them.
Heel pain is most often caused by plantar fasciitis, a condition that is sometimes also called heel spur syndrome when a spur is present.
Plantar fasciitis is an inflammation of the band of tissue (the plantar fascia) that extends from the heel to the toes. In this condition, the fascia first becomes irritated and then inflamed, resulting in heel pain.
No matter what kind of treatment you undergo for plantar fasciitis, the underlying cause-equinus- that led to this condition may remain. Therefore, you will need to continue with preventive measures. Wearing supportive shoes, stretching the Achilles’ tendon, and using custom orthotic devices are the mainstay of long-term treatment for plantar fasciitis.
Flatfoot is often a complex disorder, with diverse symptoms and varying degrees of deformity and disability. There are several types of flatfoot, all of which have one characteristic in common: partial or total collapse (loss) of the arch.
Other characteristics shared by most types of flatfoot include:
“Toe drift,” in which the toes and front part of the foot point outward
The heel tilts toward the outside and the ankle appears to turn in
A tight Achilles’ tendon, which causes the heel to lift off the ground earlier when walking and may make the problem worse
Bunions and hammertoes may develop as a result of a flatfoot.
A bunion (also referred to as hallux valgus or hallux abducto valgus) is often described as a bump on the side of the big toe. But a bunion is more than that. The visible bump actually reflects changes in the bony framework of the front part of the foot. The big toe leans toward the second toe, rather than pointing straight ahead. This throws the bones out of alignment – producing the bunion’s “bump.”
Bunions are a progressive disorder. They begin with a leaning of the big toe, gradually changing the angle of the bones over the years and slowly producing the characteristic bump, which becomes increasingly prominent. Symptoms usually appear at later stages, although some people never have symptoms.
Bunions are most often caused by an inherited faulty mechanical structure of the foot. It is not the bunion itself that is inherited, but certain foot types that make a person prone to developing a bunion. This foot type includes a tight Achilles’ tendon, or Equinus.
Hammertoe is a contracture (bending) of one or both joints of the second, third, fourth, or fifth (little) toes. This abnormal bending can put pressure on the toe when wearing shoes, causing problems to develop.
Hammertoes usually start out as mild deformities and get progressively worse over time. In the earlier stages, hammertoes are flexible and the symptoms can often be managed with noninvasive measures. But if left untreated, hammertoes can become more rigid and will not respond to non-surgical treatment.
Because of the progressive nature of hammertoes, they should receive early attention. Hammertoes never get better without some kind of intervention.
The most common cause of hammertoe is a muscle/tendon imbalance. It is this imbalance, which leads to a bending of the toe. This imbalance is from a tight posterior group, including the Achilles’ tendon.
The treatments of these conditions vary greatly. Management ranges from conservative to surgical correction of the deformity. Only your Foot and Ankle Specialist can determine the cause of your condition and the appropriate treatment regimen. Contact Dr. Paul Marciano or Dr. Sara Suttle at Academy Foot and Ankle Specialists if you suffer from foot or ankle pain. After a complete evaluation, they will formulate a treatment plan best suited for your condition to get you back on your feet!