As we use biomechanics to treat metatarsal pain, we attempt to off load directly, support proximally, and restrict when we have to.
Custom orthotic devices are one of the mainstays of successful treatment of painful 2nd and/or 3rd metatarsal pain. There can be two phases of this injury. Phase 1 (Design 1 below) is when we want to immobilize the metatarsal-phalangeal joints. Phase 2 (Design 2 below) is when we want to protect the area, but allow full function. These typically require 2 orthotic designs, used at these different times.
So, here are the typical 3 components we need in designing the orthosis. We need a metatarsal pad placed proximally to the metatarsal head (normally the sore area) seen below from superior. We need accommodation to off load the sore area with aperture of various widths. And, when we need to immobilize, we will have a sulcus extension (the most inferior of the three components) coming off the orthosis and stiff in nature (starting back onto the plastic).
Design 1, when we are trying to immobilize the metatarsal phalangeal joints, requires a restricting extension (called sulcus extension), placed onto the custom orthotic plate. This extension must start on the distal 1/3 of the plastic, and extend minimally to the sulcus area (if not to the end of the toes). Design 2, when we are trying to off weight a specific spot (say metatarsal head 2 and/or 3), starts at the end of the plastic and typically covers the adjacent non-painful metatarsals distally to the sulcus. Design 1 also has the off loading as in Design 2, and both should have a metatarsal pad proximal to the accommodation to support the metatarsal(s) that is(are) being off loaded at the head area. Please remember that if the pain is related to a dropped metatarsal, the combination of metatarsal padding and off loading accommodation, does not let the dropped metatarsal get worse. By having the restricting sulcus extension on the bottom, it makes converting Design 1 to Design 2 quite simple.
