When patients have certain occupations, you may have to take a different approach to try to control abnormal forces in the foot. Obviously, performing a biomechanical evaluation is essential as you have to identify individual demands before tackling occupation-specific modifications. With this in mind, our panelists address the more demanding occupations and what considerations come into play with orthotic modifications.
Q: How and why do you modify your orthotic prescriptions for patients whose jobs require standing in place for prolonged periods?
A: Milton J. Stern, DPM, and Ambika Mathur, DPM, contend these patients have abnormal heel to toe ambulation. Instead of propulsion with increased pressures from heel to midfoot to forefoot, they maintain constant pressure on the entire plantar surface. “Muscular activity is more for balance than propulsion,” point out Drs. Stern and Mathur. “It seems in static stance, the peroneals and the tibialis anterior and posterior stabilize each other.”
“Prescribing orthotics for complaints and pathology related to industrial situations and environments can be a frustrating or rewarding experience,” says Paul Scherer, DPM. “There is no substantial documentation in the literature about which devices with which additions work best. There seems to be some anecdotal evidence, albeit through the orthotic labs, that certain devices are more commonly used in certain situations.”
“There appears to be a big need for further research into the foot complaints of workers who stand for long periods of time,” says Lowell Scott Weil Sr., DPM. “Many of these individuals seem to suffer similar complaints that may be irritated by their occupations.”
Why Shoewear Is An Important Consideration
It’s important to evaluate the patient’s work shoes. As Drs. Stern and Mathur point out, an orthotic device controls more foot motion when the shoe has more stability. For example, they note that a high-top work boot or gym shoe will control the foot better than a loafer or flat. Dr. Stern notes each of these activities seems to put more pronatory pressure on the foot. If the orthotic is going to work, it needs help from the shoe above. A high top shoe that controls the medial foot and ankle provides more function. In a low top shoe and even more so in a loafer, the foot can pronate over the device, decreasing its effectiveness.
If workers can choose their shoes, Dr. Weil emphasizes footwear that offers good support with stiff shank, is shock absorbent and breathable. He says running shoes often fit the bill for those who aren’t required to wear steel toe shoes. If they can wear running shoes, Dr. Weil recommends removable inserts that can be changed when the shock absorption wears out or, in the case of the need for an exchange, an insole that offers additional support and cushioning.
Dr. Weil says he recently discovered the Z-COIL shoe, which has been remarkable in providing comfort to the standing worker.
“We have performed E-Med computerized footprint studies on this shoe, using the E-Med insoles and the reduction in loading of the foot is significant,” explains Dr. Weil. He notes the shoe is especially beneficial for patients suffering from heel pain syndrome but also works well in treating metatarsalgia. Dr. Weil says the shoe is roomy enough to accept a custom orthotic and he is currently evaluating the benefits of the shoe in patients with diabetes.
Addressing Specific Complaints
For complaints (leg pain, knee symptoms related to pronation) associated with the hindfoot and superior to the ankle, Dr. Weil prefers the semi-rigid devices such as the Benefoot Gait Flex-SR. A cashier may have to wear a nicer flat-type shoe and he thinks a dress orthotic such as the PAL System 3.0 could provide value. He says modifications of the orthotic would be specific to the patient’s structural malalignment or complaint.
When patients have specific forefoot complaints, Dr. Weil uses softer and cushioned devices, such as the Langer Blue Line series, whenever possible. However, he cautions that these devices require adequate room within the shoe and this is not always possible.
If there is increased plantar pressure in the forefoot, Drs. Stern and Mathur will try to accommodate the area by adding a small metatarsal pad or extra padding in an extension to the sulcus or end of the toes. They may add a Shafer plate to control the pronatory forces and give the devices more stability. For more enhanced control of the pronatory forces, they may add a deep heel cup. Drs. Stern and Mathur note they’ll also add normal rearfoot posting or a small varus increase to the orthotic.
Q: What about patients who have prolonged forefoot pressure from kneeling, stooping or squatting in their jobs?
A: For these patients, Dr. Weil favors the Sears and Red Wing work boots, citing their “excellent protection,” durability and room to add an OTC cusion or custom orthoses. He says you should add insoles in order to provide more specific accommodation. He adds that electricians may also need a special “grounding sole” for that occasional “lightning bolt.”
Forefoot pressures are increased during kneeling, stooping and squatting, and there is excessive pronatory pressure in the midfoot (even with the windlass mechanism), according to Drs. Stern and Mathur.
They suggest using a deep heel cup to try to stabilize rearfoot eversion, which sometimes can decrease medial midfoot pressure. You may need to modify the midfoot and forefoot because of increased pressure in those areas. They suggest adding some padding to the top of the orthotic and adding a Shafer plate to help with the midfoot. When it comes to accommodating forefoot pressures at the metatarsal heads, they recommend using a small metatarsal pad or cutouts of symptomatic metatarsal heads.
Q: How do you handle orthotic prescriptions for patients who carry, push and pull loads on uneven surfaces (i.e. construction, landscaping)?
A: In Dr. Scherer’s experience, mail carriers with stable and unstable midtarsal joint (MTJ) usually suffer from overuse syndromes of plantar fasciitis and lateral leg pains and fatigue.
An orthotic device for the mail carrier will bridge the forefoot to rearfoot, limiting motion of the MTJ and reducing muscle activity devoted to that effort, according to Dr. Scherer. However, the casting of the device is important. An orthotic that holds the MTJ in an even slightly supinated position will encourage motion and defeat its purpose. Casting the foot with the medial column plantarflexed ensures a good position of the MTJ, maintains Dr. Scherer.
Many podiatrists also add a reverse Morton’s extension to the devices, which requires a topcover. Dr. Scherer thinks the rationale is to encourage the first ray to plantarflex during stance and protect overuse of the peroneus longus. He says a vinyl topped EVA combination provides the durability needed for a mail carrier who walks frequently. For shoes, he recommends a thick sole, rigid shank and removable insole.
Drs. Stern and Mathur say when patients carry something in their arms, they are increasing weightbearing for the entire gait cycle. There is a little deviation of the center of gravity anteriorly, depending on the weight of the carried item. In order to provide for medial to lateral stability, they say “these individuals may need a softer orthotic with greater shock absorption to adapt to uneven surfaces.”
For those patients who carry loads, Drs. Stern and Mathur may provide orthotic accommodation via a deep heel cup and Shafer plate. Padding the entire device can help with increased weights.
When pushing loads, patients probably don’t need a lot of control in the heel area because of decreased weightbearing, although they still need midfoot control with a padded Shafer plate, the doctors maintain. They say you can achieve forefoot control for these patients via a small soft metatarsal pad and possibly metatarsal head accommodation. Drs. Stern and Mathur note that a cutout under the first metatarsal head and padded forefoot extensions might be beneficial, and they also add normal rearfoot posting for pushing and pulling.
Pulling loads requires increased control of the rearfoot, so Drs. Stern and Mathur add a deep heel cup and may increase rearfoot posting by 1 to 2 degrees. When treating these patients, they try to control any abnormal plantar pressure by accommodating the area of increased pressure.
If patients need to be on their toes because of the weight of the object they are pushing, Drs. Stern and Mathur say they’ll accommodate the forefoot forces by using a metatarsal pad and a cutout around the first metatarsal head.
Dr. Stern is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Mathur is a first-year resident at Providence Hospital in Detroit.
Dr. Scherer is Chair of the Applied Biomechanics Department of the California School of Podiatric Medicine at Samuel Merritt College and Medical Director of ProLab Orthotics/USA.
Dr. Weil is CEO and President of the Weil Foot and Ankle Institute and is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Weil is also a consultant for Langer, Inc.
Dr. Sol (pictured at right) founded the Walking Clinic, PC and practices in Colorado Springs, Colo.