Functional joint analysis of the foot in juvenile chronic arthritis.

In juvenile chronic arthritis, foot joints become affected relatively frequently. Depending on the pattern of joint involvement, different deviations or deformities can develop. The most important malpositions are pes valgoplanus, pes cavus, heelfoot (pseudocavus), hallux flexus resp. rigidus, hallux valgus, forefoot adduction and claw or hammer toes. Combinations of several deviations occur frequently. Foot involvement influences the gait pattern. Usually the heel strike phase is shortened. The loading and push-off phases are disturbed according to the pattern of joint involvement and the resulting malpositions. A muscular imbalance develops which is mainly characterized by a hypertense tibialis anterior muscle and atrophy of the triceps sursae. Successful treatment requires adequate drug therapy as well as functionally oriented individual physiotherapy supported by foot adapted insoles and partial relief from weight-bearing.