Here are two positive casts of a patient with forefoot varus. The area under the first metatarsal is marked where problems with the Root Balance Technique can occur. If you use the Root Balancing Technique with forefoot varus, you run the risk of jamming the first metatarsal not allowing crucial first ray plantarflexion for propulsion.
The line running obliquely across the foot represents the longitudinal axis of the midtarsal joint. It is important for proper foot function that the weight of the foot passes laterally to this line, keeping both midtarsal joints pronated in midstance and propulsion. When supporting the forefoot varus deformity, the Root Balance Technique can produce too much pressure under the first metatarsal causing long axis supination interfering with proper foot function.
This has been a problem long recognized by the orthotic industry. Compromises in support are being made with this foot type daily. It is important to realize that they are compromises, and suboptimal support is achieved. Suboptimal support can lead to poor symptom response, and even the creation of bunions, etc. Even in patients with 2 or 3 degrees of forefoot varus, I will try to modify the correction to place more support proximally with the Inverted Technique or the Kirby Skive. This way the anti-pronation support is not compromised, and the possibly damaging problems associated with full forefoot varus correction are eliminated.
