Many people wear special footwear at work.  Occupational health guidelines and employers often require the use of protective work boots.  When fitting patients for orthotics, ask what type of footwear is worn throughout the workday, as well as during recreation and relaxation periods.  An orthotic designed for work boots can be very helpful.  While generic insoles and off-the-shelf foot supports provide some comfort, workers appreciate a custom-made orthotic designed specifically for work boots.

Protection from Injury

Work boots protect the feet and ankles from work-related injuries.  This category of footwear contains primarily ankle-high boots made from thick, sturdy materials.  Most have a special sole, which varies depending on the work conditions (slip-resistant rubber, large lugs for traction, non-conductive to electricity, etc.).  Many also have steel, non-crushable protection for the toes.  These boots are often quite heavy.  Because weight on the feet leads to fatigue, a lightweight orthotic is appreciated.  Check the weight of the orthotics you recommend for work boots.

Support for Ankles and Arches

Better work boots provide excellent external support and help hold the foot and ankle in alignment during strenuous activities.  However, the insole must fit the many different shapes of feet that wear that same size.  Therefore, the internal support is generic, with a strong shank under the arches, but no specific support.  Foot and ankle fatigue increases as the workday progresses, especially for workers with non-standard feet, whether flat or high-arched.  A custom-made orthotic improves foot and ankle function during strenuous work activities.  It must cause little or no interference in the proprioceptive feedback system, and the foot and ankle must be kept in good balance.  This means controlling the amount of pronation during gait, preventing excessive ankle and calcaneal eversion, and supporting the three-arch complex.

Support for the Pelvis and Spine

The best work boot orthotic also ensures proper alignment of the pelvis and spine.  Biomechanical asymmetries transmit abnormal forces into these areas, resulting in persistent subluxations and susceptibility for back injuries.  The integration of a pronation wedge or heel lift, when needed, can greatly improve the function of the pelvis, sacroiliac joints, and spine.1  Many chronic back conditions associated with work postures resolve when custom-made orthotics are worn in work boots.

Shock Absorption

Long-term standing on concrete and other rigid materials can lead to back problems.  The best modern orthotics are designed to reduce shock waves generated up the leg into the knee, hip, and spine.  The best materials for work boot orthotics are the viscoelastic polymers (such as Zorbacel® and Poron®), a group of materials created to enhance the body’s ability to dissipate shock stress to sensitive and easily damaged tissues.2
Viscoelastic shoe inserts can significantly reduce reported pain levels in patients with low back pain.3  A report on soccer referees participating in a five-day tournament found, “The incidence of soreness in Achilles tendon, calf, and back were significantly reduced by the use of shock absorbing heel inserts.”4  Orthotics made for work boots should take full advantage of the newer viscoelastic materials.

Moisture Control

The sturdy construction of work boots often causes substantial heat accumulation, especially when working indoors, or during the summer.  Sweat often builds up, which can result in foot odors and fungal infections.  The feet can excrete as much as half a pint of moisture daily.5  Orthotics for work boots should incorporate special materials that pull sweat away from the foot surface.  Such an orthotic is able to control most cases of hyperhidrosis, and even normal foot moisture is handled efficiently.

Additional Orthotic Concerns

Comfort.  A good orthotic must be easy to fit into the work boot, with a minimum of modification.  There should be no sensation of “something in my shoe,” which would distract from work performance.  The newer materials tend to be more comfortable and less intrusive.  The break-in period is usually much shorter, and workers quickly become accustomed to custom-made orthotics designed with viscoelastic polymers.  An orthotic used during work must be supportive, yet flexible, so that it doesn’t hinder natural biomechanical performance.  Longitudinal flexibility (especially at the forefoot) is a major indicator of a comfortable orthotic for work boots.
Durability.  Since many work activities produce high forces and stresses on an orthotic, it must be capable of sustaining repetitive physical insults, with no perceptible decrease in support, performance, or shock absorption.  Moisture and heat must not cause significant degradation of any of the above factors.  Once again, the newer materials are usually the most durable, and their physical characteristics can be maintained the longest.

Conclusion

Orthotics need to be specifically selected for use in work boots.  They should support the arches and spine, be lightweight, and offer shock absorption, moisture control, comfort, and durability.  Patients with properly fitted and selected orthotics for their employment have noticeably less work-related fatigue. TAC

Dr. John J. Danchik is the seventh inductee to the American Chiropractic Association Sports Hall of Fame.  He is the current chairperson of the United States Olympic Committee’s Chiropractic Selection Program.  He lectures extensively in the United States and abroad on current trends in sports chiropractic and rehabilitation.  Dr. Danchik is an associate editor of the Journal of the Neuromusculoskeletal System and the Journal of Chiropractic Sports Injuries and Rehabilitation.  He has been in private practice in Massachusetts for twenty-six years.

Tarsal tunnel syndrome (TTS), while not common in the general population, is occasionally seen among athletes.  In addition, many TTS symptoms can be confused with conditions commonly treated in the chiropractic office.¹  Because its etiology is often related to hyperpronation and, therefore, spinal complaints, TTS patients may be concentrated in the chiropractic office.  When a patient complains of burning pain or numbness of the foot or ankle, keep TTS on your list of differential diagnoses, including plantar fascitis, Achilles tendinitis, and lumbar radiculopathy.

Similar in function to the carpal tunnel, the tarsal tunnel is formed by the following borders:  medial calcaneus, medial malleolus, posterior talus, and flexor retinaculum.  Structures passing through these confines include tendons, blood vessels, and the posterior tibial nerve, including its branches, the medial calcaneal, medial plantar, and lateral plantar nerves.

These sensitive structures are susceptible to any direct trauma or lesion that decreases the available space.  The athlete runner with a recent history of increased activity is particularly vulnerable, but also consider any auto accident victims who have jammed their lower extremities.  The energy at impact, sent through the pedals or floorboard and into the feet and ankles, supplies the force necessary for traumatic TTS.  On the other hand, consider the simple act of walking on an excessively pronated foot, which is far more common among patients. 

The review of eighty-seven TTS cases revealed that biomechanical deformities, including tarsal jamming and hyperpronation, were to blame and could be documented radiographically.²  Furthermore, it has been proposed that even minimal trauma during weightbearing activities in persons with pes planus is the most likely mechanism for TTS.  This same study postulates that when pes planus is functional and associated with malposition of the tarsals, the posterior tibial nerve is stretched with each step taken.³  Tarsal malposition is evident with toe out greater than fifteen degrees and with excessive bowing of the Achilles tendon, when viewed from behind.

The symptoms of TTS can be easily confused with plantar fascitis and, in extreme cases, with lumbar radiculopathy.  In the case of biomechanical overuse, the patient will report poorly localized numbness and tingling of the medial ankle and on the plantar surface, which may extend into the lateral two toes (the lateral plantar nerve being more commonly involved). 

Unlike plantar fascitis, which is generally worse in the morning, TTS is worse at night after activity and may include pain radiating up the medial calf.  The physical exam may reveal loss of two-point discrimination and muscle strength in the distribution of the lateral plantar branch and a positive Tinel’s sign, found when tapping directly over the site of the tarsal tunnel.  A normal Achilles reflex should help rule out lumbosacral radiculopathy.

Initial treatment of TTS includes inflammation reduction of the involved tissues.  This means no weightbearing without the foot and ankle taped or without orthotics in place.  Next, adjustments should be used to restore normal biomechanics throughout the entire kinetic chain (foot, ankle, knee, hip, and spine).  Special attention must be given to the valgus misalignments of the talus and calcaneus.  Additionally, deep friction massage over the flexor retinaculum may release adhesions responsible for compression symptoms.
Most importantly, correct the underlying foot dysfunction (hyperpronation or otherwise).  Pes planus causes tightening of the flexor retinaculum, which can then compress structures within the tunnel.  Although the inflammation may go away, the nature of ligament stretch means that any plastic deformation is permanent (barring surgical intervention).  Therefore, effective and lasting treatment necessitates the use of custom-made, flexible orthotics, which have been demonstrated to control the degree of pronation, as well as the percent of time spent in pronation.

Although relatively uncommon, tarsal tunnel syndrome can present a diagnostic and treatment challenge.  Understanding the etiology of this entrapment syndrome is important for providers concerned with the treatment of athletes and auto-accident victims.  Also, because TTS is often associated with hyperpronation, patients will likely experience other conditions also associated with a faulty foundation, including knee, hip, and low back pain.  Many of these patients will seek care from chiropractors, where treatment consisting of adjustment, soft-tissue technique, and the use of flexible orthotics can offer excellent symptom relief.

Dr. John J. Danchik is the seventh inductee to the American Chiropractic Association Sports Hall of Fame.  He is the current chairperson of the United States Olympic Committee’s Chiropractic Selection Program.  He lectures extensively in the United States and abroad on current trends in sports chiropractic and rehabilitation.  Dr. Danchik is an associate editor to the Journal of the Neuromusculoskeletal System and the Journal of Chiropractic Sports Injuries and Rehabilitation.  He has been in private practice in Massachusetts for twenty-six years.