Biomechanical Basis for Treatment of Pediatric Foot Deformities Part II: Pathomechanics of Common Foot Deformities

The biomechanical basis for causation and treatment of pes planus, convex pes valgus (vertical talus), pes cavus, paralytic deformities, and foot deformities in cerebral palsy are presented. In each instance, the altered alignment of the hindfoot and forefoot, the configuration of the medial longitudinal arch and the instability of the talonavicular joint differ. The patterns of muscle imbalance across the axes of movement in paralytic deformities and the concept of treatment aimed at muscle rebalancing across these axes are graphically illustrated. The common deformities of the foot encountered in cerebral palsy are described and, in particular, the different deformity patterns resulting from spasticity of the gastrocnemius. The importance of preserving the function of the soleus and avoiding over-lengthening of the gastroc-soleus is emphasized. Key Concept: • Common deformities of the foot are complex and have deformity components involving the hindfoot, the forefoot, the longitudinal arch, the talonavicular joint and the alignment of the talus.