Case Study: Treating Chronic Pain In A Middle-Aged Distance Runner
What The Gait Analysis Reveals
When the patient returned for his gait analysis exam, we took digital video of him utilizing four camera views. We utilized in-shoe pressure analysis in his shoe without orthoses and then with his temporary orthoses in his shoes. We utilized approximately seven separate tests or walking trials with the in-shoe pressure analysis. We made modifications to the orthoses or a unilateral orthosis singularly for each test.
According to the patient’s first test, the center of pressure on his static in-shoe images was more laterally deviated on the left foot. The patient also had faster accelerations with his right foot. One can often attribute these acceleration differences to a functional or structural short limb (see photo at left). In this case, the chronically flexed right knee may be acting as compensation for an opposite limb length difference.5-6
This patient’s force versus time curves showed a significant delay or prolongation in his heel curves (see photo at right). This often occurs in patients with an ankle equinus deformity and/or significant pes planus with functional hallux limitus. In this case, the patient has an early heel lift due to his chronic knee flexion. This causes him to load the forefoot very early in stance. This in turn delays the heel unloading of his right foot and causes a disruption in his gait, which often leads to chronic back and limb pain.
How Orthoses Helped The Patient Return To Running Without Pain
We performed six more in-shoe pressure tests and considered orthotic modifications before concluding with an orthosis prescription that we thought was best for the patient. The final prescription consisted of a 3 mm EVA heel lift on both orthoses plus a 1.5 mm PPT™ (Langer Group) heel lift on the patient’s right orthosis.
The hard heel lifts help to combat the ankle equinus of both feet. The soft heel lift helps to address acceleration issues in the right limb as the patient tended to lift that heel early and accelerate faster on that right side. The soft PPT heel lift seems to act as a dampener, delaying accelerations slightly and often helps to equalize accelerations in asymmetrical limb function.
I also added a kinetic wedge modification to the patient’s orthoses along with a lateral forefoot wedge on the right device. Both of these modifications assist in driving the foot to load the first metatarsophalangeal joint (MPJ) in late midstance as the heel is lifting. This should assist the function of the plantar fascia.
The final part of the patient’s prescription consisted of a bilateral medial heel skive modification with a 3 mm metatarsal pad. He also received a digital skive, similar to a Cluffy Wedge™ (Cluffy Biomedical), of 6 mm on the left and 3 mm on the right. The digital skive assists plantar fascia and first ray function as does the metatarsal pad through allowing the first and fifth rays more room to plantarflex during the stance phase. This should lend stability to the midfoot as it begins to load the most in the transition to heel off.
The final force versus time curves show an elimination of the delays in the heel and forefoot curves (see photo above left). The final static foot images show a more medial center of force progression and more equal pressure distributions as well (see photo on next page).