In the diabetic population, equinus is the overwhelming commonality between patients suffering from plantar wounds associated with diabetic neuropathy. Equinus, to explain it simply, is a lack of dorsiflexion, or the ability to raise the foot at the ankle joint past 90 degrees (neutral position). The ankle and foot function best in gait when dorsiflexion at the ankle is at least 10 degrees past the neutral position. When this is decreased, excess pressure is placed on the plantar forefoot throughout gait, and increased pressures automatically lead to an increased risk in ulceration.
Patients develop equinus from a lack of flexibility in the musculature of the leg, namely the calf. Whereby, dorsiflexion becomes decreased because it is those muscles in the calf that are responsible for lifting the foot above that neutral position during gait. If those muscles are tight or contracted, which occurs in patients who don’t stretch or exercise on a regular basis, equinus and increased forefoot pressures result.
Increased pressures in any area of the foot create a major risk in the diabetic patient, and such pressures can also be induced by tight-fitting shoes, open-toed sandals that rub between the toes, and areas of friction along with bunion prominences or on the tops of contracted digits (hammertoes) in closed-toed shoes. The reason increased pressures are such a risk is that in places of friction, typically not felt by the neuropathic diabetic patient, a pre-ulcerative lesion may develop. The area goes undetected unless you’re religiously checking your feet on a daily basis for new lesions (which you should be doing!), and the pre-ulcerative lesion turns into a wound.
Again, you are faced with the issue of non-healing secondary to poor circulation (which we discussed last week), such that the nutrients needed for wound healing carried by the blood have difficulty getting to the area. In addition, if you have not addressed the issue of equinus or the problem shoes that created the initial friction, you’re bound to have problems in the future, even if you’re able to heal this time around. So what can you do? Again, the answer is prevention!
There are two important ways in which you can take control of the deforming forces of equinus and increased pressures placed on the foot:
- Stretch – By stretching the musculature in your calf and increasing the flexibility around the ankle joint (decreasing your equinus), you will greatly decrease pressure placed on the plantar forefoot and decrease your risk of ulceration. There are several exercise, that are easy to do:
- Wall Stretch: With your feet shoulder width apart, one foot in front of the other, place your hands on the wall in front of you. Keeping the back leg straight and the front leg bent slightly at the knee, lean into the wall. You should feel a light stretch in the calf of the straight leg. Hold this for 20-30 seconds, take a 15 second break and repeat 10 times. Then switch front and back feet, so that you can stretch the opposite side. Again, hold for 20-30 seconds, repeating 10 times.
- Heel Drop: This exercise will require a set of stairs with a railing available for balance. Place the balls of both feet on the step, knees straight and allow the heels to suspend off the step and drop down below the level surface via your body weight. You should feel a light stretch in the calf of both legs. Hold this for 20-30 seconds, take a 15 second break and repeat 10 times.
- Invest in a pair of diabetic shoes – Especially important for those patients with diabetic neuropathy, but important for any diabetic patient. Diabetic shoes have a custom molded insert with a wide and deep toe box. The insert is made from a mold of your foot and alleviates all areas of pressure on the plantar foot. The wide and deep toe box allows the foot room within the shoe, preventing areas of friction on boney prominences. Diabetic shoes essentially alleviate all friction areas, thus decreasing your risk of pre-ulcerative areas and ultimately of developing an open wound.
As you can see, the power again remains in your hands when it comes to decreasing your risk of complications associated with diabetes! With diet and exercise, controlling your blood glucose levels, managing your co-morbidities, and preventing areas of pressure in the foot, you’ll be well on your way.