A simple shoe modifier may reduce pressure and disability in metatarsalgia patients, according to Fred Lerche, CPed, PT and Phil Voi, CPed, PT of CoxHealth in Springfield, Mo. Lerche and Voi presented their findings at the Pedorthic Footwear Association (PFA) Symposium in November 2009.
Metatarsalgia is defined as the pain in the plantar forefoot. Possible causes of metatarsalgia include repetitive loading under the metatarsal heads, biomechanical issues that could cause disequilibrium, atrophy of the plantar fat pad, or a patient’s pathological conditions.
Patients treated with an external shoe modification called the Hunt Metatarsal External Shoe Cut-Out (HMESC), showed an immediate decrease in mean peak pressure under the metatarsal heads and a significant decrease in foot disability over the treatment period, according to presenters The HMESC is a 5-mm thick compressible crepe soling with a 2- to 4-cm oval-shaped cut-out to reduce metatarsal head pressure.
Lerche and Voi presented a case study of a 59-year-old female patient who was suffering from metatarsalgia in her right foot. The presenters noted that the patient had swelling and pain on her plantar metatarsal, which caused her decreased ability to ambulate for long distances. The patient also presented pain in mid-stance and propulsion phases of walking.
Lerche and Voi treated the patient using the HMESC. The external shoe modification was applied to the outsoles of the patient’s most frequently worn shoes and was worn for at least 32 hours per week over the treatment period. By placing the modification on the patient’s most frequently worn shoe, Lerche and Voi are decreasing the risk of patient non-compliance. They are expecting that the patient will wear the modifier because it will be placed on self-selected shoes.
The results indicated that the HMESC could become an effective treatment in reducing the symptoms of metatarsalgia. According to Lerche and Voi, the HMESC is a simple and flexible device to reduce plantar pressure.
“Most of the time we have seen improvement,” Lerche said at the PFA symposium. “It is simple. It is easier to adjust, it is an easy technique to do and the patient gets out the door that day with the treatment.”
According to Voi, the construction of the HMESC takes no longer than 10 minutes. This allows for easy testing and retesting of the device should the patient not feel comfortable after its original construction.
Voi pointed to the shoe modification’s versatility as one of its greatest benefits. The modification can be taken off or made permanent if the patient feels immediate relief. — Anthony Calabro
I would like to compliment the original presenters on their ingenuity, but I totally disagree with their conclusions as stated here. Any pressure relief is not accomplished by the design of this device; it’s because adding material to the forefoot effectively lowers the heel creating a poor man’s Earth shoe (negative heel).
The biomechanical drawback of the device is it being apexed directly under the metatarsal heads, thereby increasing the load to the medial and lateral metatarsel heads.
By transferring the load more posterior, the gait is slightly retarded with more time being spent in midstance. This benefit is negated with the HMESC in the transition from midstance to toe-off without an apex at the proper moment.
The posterior apex should be proximal to the metatarsel heads, while the distal apex should start tapering at the distal edge of the hole. This may seem to be a minor refinement, but it would increase the biomechanical functionality exponentially.
—Shane Hayes, CPed
Shane’s Foot Comfort Center