Conway McLean, DPM, Journal columnist

Being able to comfortably and safely stand and walk should be considered an important skill. Don’t take it for granted. Those deprived of safely being able to stand up from a chair, to stand in place without falling, to walk, can tell you. There’s a decrease in both quality of life and in health. And a single fall can irrevocably change your life forever…..and not in a good way.

What does someone do when they aren’t able to stand without feeling like they are going to fall over? This is the situation when someone suffers from gait instability, a term referring to the loss of position sense and the inability to maintain an upright, stable position without falling. Anyone will tend to walk less if they have no confidence in their ability to stay upright. And for many of us, this translates into less exercise.

Falls, one possible result of gait instability, are a tremendous problem and cost our healthcare system over 100 billion dollars a year. Of course, there is the disability and death that also are a frequent consequence. The risk of falls may be increased by a long list of potential causes, and foot pain is well recognized as one. But a common reason for foot pain that isn’t well known is pain from a critically important joint, the (not) famous subtalar joint.

The ankle joint, for example, is common knowledge; everyone knows where it is. It is a simple hinge type joint, providing up and down motion. The subtalar joint is the joint immediately below the ankle….and it is not simple. This is the joint that is moving when your foot goes side to side. Every step you take involves this essential articulation.

To absorb the impact forces of the foot landing on the ground (with all of body weight on top of it), the subtalar joint (the STJ) allows the arch to act as a shock absorber, dampening the shock of the limb hitting the ground. These forces have a detrimental effect on the human body when this joint isn’t functional. But it is also critical to the other part of gait, where the foot propels the body forward by pushing off from the ground. This component of the walking cycle allows the body to move forward, moving you through space.

The arrangement of the STJ complex is unique, composed of three separate joint surfaces. It is found between the heel bone and the talus, the bone which composes the bottom part of the ankle joint. How these joint surfaces are positioned determines how well this vital joint functions to work the arch of the foot. Abnormalities in the organization of the STJ can spell trouble for many other body parts. The feet are the foundation for the human body and can profoundly affect a variety of structures, from top to bottom.

Chronic inflammation can develop in this joint space for various reasons and can manifest as an inability to stand. Many of those afflicted describe it by saying “my leg just gave out!” Because the brain works to avoid a painful situation, when the STJ is symptomatic, the brain doesn’t want to let you stand. It’s a reflexive action, like pulling your hand back when exposed to a flame.

This joint is often injured in many ankle sprains. Many experts believe it to be quite common, although it is difficult to say since it is rarely diagnosed accurately. I can speak personally to this issue, having sprained my left ankle badly as a young adult. Like so many before me, poor advice was dispensed by the health care provider. Consequently, in the years to come, in x-rays and in life, it became apparent significant damage was incurred by my subtalar joint. Although there can be notable symptoms, thankfully, no instability has presented itself.

Biomechanically, the STJ is considered a bit of an enigma, it’s exact mechanical function not well defined. But we know well of the many problems which may beset this articulation. One of them is a foot type that can physically stress the joint under discussion. As should be obvious, this is a chronic situation. But we are not talking about a noticeable deformity, only a slight variation from normal. But the cumulative effect of this subtle malalignment, over the years, with every step, can result in pain or instability.

The subtalar joint is not well innervated, meaning there aren’t many nerves. Inflammation here appears to produce a subtle sensation, what often is described as an unstable feeling. This is commonly treated with a steroid (cortisone being an earlier incarnation) and often quite helpful….for symptoms. But if the joint continues to be stressed, the symptoms will usually redevelop.

When the joint has been damaged sufficiently, surgery may be necessary to fuse it. But this obviously alters foot function and the mechanics of the lower limb. Prior to such an invasive, joint-destructive procedure, great relief of pain may be obtained with use of some regenerative medicine technique, amnio-injections being particularly effective. This technique involves a simple, nearly painless procedure. The benefits are typically lasting, since the growth factors provided bring stem cells to the area, leading to real healing of the joint.

When the root of the problem is the individual’s foot mechanics, preventing the damage is the healthiest approach. Reducing the abnormal motion is possible with precisely prescribed and fabricated in-shoe bracing. Most of us refer to these devices as foot orthoses, aka orthotics, which are essentially prescription, custom arch supports. But many health care providers don’t have the training or expertise to prescribe and, consequently, many people who have been dispensed these find them unwearable, or at least uncomfortable. Unfortunate since, when properly prescribed, they can safely resolve a multitude of lower extremity pains and problems.

Many Americans will continue to live their lives with undiagnosed STJ disease, uncertain why their leg can give out or why their “ankles” hurt. Most health providers aren’t familiar with this vital articulation and its complex mechanics. Chronic use of anti-inflammatories, reduced activity levels, or unnecessary surgical procedures are all common methods of dealing with this condition. A visit to a specialist may be required to accurately diagnose it. As has been often repeated, don’t live with foot pain. The big picture consequences aren’t good and include impaired circulation, reduced heart health, and diminished quality of life. All are things to be avoided.

Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula. Dr. McLean’s practice, Superior Foot and Ankle Centers, has offices in Marquette and Escanaba, and now the Keweenaw following the recent addition of an office in L’Anse. McLean has lectured internationally, and written dozens of articles on wound care, surgery, and diabetic foot medicine. He is board certified in surgery, wound care, and lower extremity biomechanics.