In my last posts, I have been talking about feet that have a tendency to pronate, but can easily be supinators (inverters). These include patients with either genu varum or valgum, high tibial varum or valgum, intoed patients, and patients with very unstable lateral ankle ligaments or weak peroneals. Their feet may be classified as pronators, but it is easy for them to supinate and cause problems. We also talked with Dr. Mark Warford about the uniqueness of Parallelogram Feet and the need for asymmetrical prescriptions. And in the last post, we discussed patients who pronate in one activity and supinate in another. This also requires different orthoses for different activities.
Today, we will discuss something more classic. This foot has so many variations in movement, but the main one observed is the contact phase supination followed by late midstance pronation. It is a timing issue. The opposite should be occurring. These are your everted forefoot deformities. They are forefoot valgus, plantar flexed first rays, and forefoot pronatus (functional deformity like forefoot supinatus). The more rigid the foot is, or the more plantarflexed the first metatarsal, the more you will see this gait pattern. It tends to be recognized in gait, with the hardest part visualized being the contact phase supination. Sometimes you observe just no pronation at contact phase. Normally you will observe the lateral side of the leg moving more lateral. Occasionally, and shoes help, you will see the heel inverting. As the person walks towards you, the key will be in no arch collapse until late in the step (only sometimes you can see this from the back).
Unfortunately, since most of you use different casting/imaging techniques, this is only captured with neutral suspension casting described by Dr. Root, et al. If I see someone with this gait pattern, I want my image to capture an everted forefoot deformity that I can balance out. You get a great lateral column with this technique that will stop the contact phase supination, and allow for contact phase pronation. Many believe that this does not exist, but again it is how you cast. Since Root casting is common knowledge, when you see this gait pattern, and you believe the supination is causing problems, consider taking a Root impression cast to see if you can be helped by capturing an everted forefoot deformity. An orthotic device that eliminates any forefoot valgus compensation gets the foot moving better with less stress.
Another Forefoot Valgus or Plantar Flexed First Ray with Heel Contact Phase Inversion (Supination) to compensate
Everted Forefoot Deformity Captured in this Left Foot which will set Inverted on the table. The Lab will balance this to heel vertical typically providing incredible lateral column support as the cuboid and 5th metatarsal base is lifted off the ground.
