Central to the classification system of Root et al is the concept of the dysfunctional 'excessively pronated' foot, which has been associated with numerous pathologies inluding hallux abducto valugs, knee pain, and shin splints. The role the subtalar joint may play in running injury is conceptualized in the following way. Root et al, 1977. Abnormal pronation is an excess amount of pronation or pronation occuring at the wrong time of the stance phase.
Abnormal pronation is thought to lead to hypermobility.
Root et al, 1977. The greater the degree of hypermobility, the greater the eventual pathology. Therefore, the greater the abnormal pronation, the more abnormal the foot. Root et al, 1977. This thought process has lead clinicians to implicate subtalar malalignment as a theoretical causative factor of overuse running injury.