RELATION BETWEEN HEEL POSITION AND THE DISTRIBUTION OF FOREFOOT PLANTAR PRESSURES AND SKIN CALLOSITIES IN RHEUMATOID-ARTHRITIS

Objective-To investigate the relation between the position of the rear foot and the distribution of forefoot plantar pressures and skin callo sities in rheumatoid arthritis. Methods-Plantar pressures and callosit y patterns were measured in 102 rheumatoid arthritis patients (120 fee t with normal. heel alignment and 84 feet with valgus heel alignment m easured by goniometry) and in 42 (84 feet) age matched healthy adults. Peak pressures (kPa) were measured across the metatarsal heads in-sho e using an FScan system and the distribution of plantar callosities wa s visually mapped for each foot. Results-Peak pressures were significa ntly greater at all but the first metatarsal head in the rheumatoid no rmal heel alignment and healthy adult groups than in the rheumatoid va lgus heel group. The feet of both the rheumatoid normal heel group and the healthy adult group behaved the same, the highest peak pressures registering on the central metatarsal heads. However, only in the rheu matoid group were plantar callosities found at these sites. In the rhe umatoid valgus heel group, lateral metatarsal heads were frequently no n-weightbearing, producing gross loading patterns with a dominant medi al distribution. Peak pressures were shifted to the medial forefoot ac companied by a higher prevalence of callosities. The results, however, failed to establish clearly an association between peak pressures and callus formation. Conclusions-In rheumatoid arthritis there is an imp ortant interrelation between the rearfoot position and forefoot pressu re sites.