How many of your patients’ issues point to excessive weight, the toll on aging feet and a change in gait?
It has been estimated that more than 20% of Americans will be older than 65 by the year 2030.1 As our society ages, the average age of our patients is also increasing. That fact often isn’t really noticed, though, since we’re getting older at the same time! If you take a moment to review your current practice, I’ll bet that you’re seeing more chronic, age-related conditions than you were 10, or even just five years ago with aging feet.
This should also mean that your use of orthotics has been increasing. If it hasn’t, then you’re missing some critical factors in treatment, and your patients are not benefiting from your chiropractic care as they should.
Aging feet cause a variety of problems
With aging, a number of important conditions begin to affect the feet. Some of these are not immediately symptomatic, and often the patients are unaware of the deterioration until they develop a loss of functional capacity and independence.
Once we begin to pay attention, we will discover a variety of problems in the feet of our aging patients, some biomechanical, others systemic. Many of them can be helped with comprehensive chiropractic care, along with custom-made, flexible orthotics.
Excessive weight, obesity and the feet
Depending on the specific population studied and the exact definitions used, most researchers have found that somewhat more than half of all adult North Americans are overweight, and from 20-30% of our society is defined as obese.
As we age, we tend to put on more weight. Since the additional weight load places more stress on the supportive skeletal structures, it’s not surprising that overweight results in a greater frequency of musculoskeletal and arthritic problems, especially in the knees and feet. Lower extremity biomechanics are very different in the overweight patient, and many gait changes and abnormalities are commonly seen.
During walking, obese individuals take shorter steps, have an increased step width, and walk more slowly. They have increased Q-angles at the knee, more hip abduction, significantly more abducted foot angles, and increased out-toeing (foot flare). Overpronation is greatly increased, with a greater touchdown angle, more eversion of the foot, a more flat-footed weight acceptance period in early stance, and a faster maximum eversion velocity being measured. There is also greater ankle dorsiflexion, but less plantar flexion.
In a study reported in Biomechanics, orthopedic surgeon Carol Frey, MD, described the effect that being overweight has on the prevalence of foot problems. She found that 38% of the participants were overweight or obese, and that these overweight patients had experienced a higher incidence of plantar fasciitis, tendinitis, osteoarthritis, and fractures and sprains of their feet and ankles.2
A study by MaryFran Sowers, PhD, found that overweight women have an increased incidence of developing osteoarthritis during mid-life. 3 She reported that the “articular cartilage suffers more wear and tear, which eventually leads to osteoarthritis. Overweight women are at even greater risk because they carry a heavier load.”
This tendency is the same for men, and is accentuated when overweight people begin an intensive, regular walking exercise program in an attempt to lose weight.
Osteoarthritis
Joint degeneration becomes much more prevalent as we age. In the feet, the small joints are exposed to high forces over many years. While the causes of joint degeneration and osteoarthritis are still debated, several studies have clearly demonstrated that repetitive impact loading from a variety of sources results in the development of osteoarthritis. 4,5
When a joint is exposed to cyclic impact forces, the appearance of degenerative changes is only a question of time. 6 These repetitive forces cause a “fatigue-failure” in the joint tissues, a well-known phenomenon that includes alterations in both the articular cartilage and the cancellous subchondral bone. When this type of intermittent dynamic loading is combined with biomechanical faults, previous injury to a joint, or a rigid, non-yielding walking surface, degenerative changes progress rapidly and symptoms frequently develop.
Diabetes and circulation problems
Due to their problems with circulation, patients with diabetes often develop extremity problems and symptoms — most commonly of the feet. As the diabetic process continues, neuropathy can lead to sensory difficulties, which often allows poor shoe fit, excessive pressure and friction, and even injuries to go undetected. The eventual result is skin ulcerations, infections (which do not heal readily), and finally, amputation in some cases.
When treating a diabetic patient, we must check the circulatory status in the extremities, and provide advice to help prevent the development of foot ulcers. It is important to remember that in most people the foot is seldom symptomatic (so your patient will probably not remind you of its importance), and this is particularly true in the case of patients with a history of or tendency to diabetes. Proper shoe selection can be critical in avoiding excessive frictional stresses to sensitive foot tissues. Slip-on styles are usually not recommended for patients with diabetes, due to the lack of adjustability and the need for a tight fit.
Another important consideration is preventing damage to the heel pads and absorbing the stresses of walking. The normal shocks and stresses our feet are subject to often result in damage and injury to sensitive diabetic feet.
Plastic deformation and breakdown
Over a period of years and decades, repetitive stresses and normal forces result in a slow breakdown of support for the bones and joints of the feet. It is the connective tissues (collagen and proteoglycans) that are exposed to these long- term lengthening forces, resulting in a decrease in elasticity and a sagging of the foot’s arch. This breakdown then allows transmission of abnormal strains into the legs, the pelvis and ultimately the spine.
Since it is usually the spinal symptoms that have brought the patient into the chiropractor’s office, the doctor must be able to identify the underlying foot dysfunction.
The tissues that must withstand this strain for years are the connective tissues (ligaments, tendons and fascia), which are composed primarily of woven collagen fibers. This arrangement allows for the combination of flexibility and strength that keeps our joints within close alignment, while still allowing for a wide range of movement.
The woven collagen fibers demonstrate a very important physical property — viscoelastic behavior. Viscoelasticity is the time- dependent response of tissues to a load. 7 The longer a load is imposed on the tissues, the more likely it is that there will be enough stretch to result in a permanent lengthening.
The physical properties of collagen are closely tied to the number and quality of the cross-links between fibers. During growth and maturation (up to 20 years of age), the cross-linkages increase, resulting in increased tensile strength of tendons and ligaments. 8 As aging progresses, cross-linking activity plateaus and the collagen content of ligaments begins to decrease. This causes a gradual decline in the elastic capability, facilitating creep and the development of permanent plastic deformation.
The process is tremendously variable and occurs at a wide range of ages and activity levels. The result in many aging patients is a loss of elastic support for the arches of the foot, and less shock absorption from the heel pads. Providing support for the aging foot’s arches can help prevent problems such as plantar fasciitis and heel spurs, which often develop as the foot ages.
New challenges
The aging of our population provides us with new challenges. Many of the chronic conditions reported by older patients will respond best when their chiropractic care is augmented by custom-fitted orthotics.
With new materials and innovative construction techniques, orthotics are now being designed to meet the needs of this growing segment of our communities. When your “more mature” patients get relief from their chronic, degenerative conditions under your care, they’ll help build your practice with referrals.
And don’t forget that this part of our society has a surprisingly large amount of spendable resources. They will be more than willing to pay for orthotics with three-arch support that bring them relief that they couldn’t find anywhere else. The use of orthotics will often complement and improve the chiropractic adjustment, while assisting the body to return to an improved state of function and health.
MARK CHARRETTE, DC, is a 1980 summa cum laude graduate of Palmer College of Chiropractic and can be reached at footlevelers.com.
REFERENCES
[1] U.S. Census Bureau. https://www.census.gov/newsroom/press-releases/2014/cb14-84.html
[2] Frey C. Obesity and foot problems. Biomechanics 1996; January.
[3] Sowers M, et al. Body weight, bone density, and arthritis risk. Am J Epidem 1996; January.
[4] Paul JL. Musculoskeletal shock absorption: relative contribution of bone and soft tissues at various frequencies. J Biomech 1978; 11:237-42.
[5] Radin EL. Effect of repetitive impulsive loading on the knee joints of rabbits. Clin Orthop 1978; 131:288-91.
[6] Radin EL. Effect of prolonged walking on concrete on the knees of sheep. J Biomech 1982; 15:487-94.
[7] White AA, Panjabi MM. Clinical biomechanics of the spine. 2nd ed. Philadelphia: Lippincott, 1990. p. 692.
[8] Nordin M, Frankel VH. Basic biomechanics of the musculoskeletal system. 2nd ed. Philadelphia: Lea & Febiger, 1989. p. 68.
