Abstract
Minimal published data exist characterizing the effect of rheumatoid arthritis of the forefoot (RA) on multiโsegmental gait kinematics. The purpose of this study was to examine specific changes in segmental foot motion in patients with RA as compared to persons without foot/ankle pathology. This was a crossโsectional, descriptive study consisting of 22 preoperative adult patients (29 feet) diagnosed with RA and 25 adult patients with no known foot pathology (Control). All RA patients were evaluated by the same orthopaedic surgeon. This group consisted of 20 women and 2 men with a mean age of 54 years (range, 17โ76 years). The Control cohort consisted of 13 men and 12 women with a mean age of 41 years (range, 27โ73 years). Foot and ankle motion data for the RA population were obtained using a 15โcamera Vicon Motion Analysis System (Vicon Motion Systems, Inc., Lake Forest, CA). Anteriorโposterior, lateral, and modified coronal radiographic views were obtained to relate marker position to underlying bony anatomy. Temporal and threeโdimensional kinematic parameters were obtained via the 4โsegment Milwaukee Foot Model. Quantitative comparisons of range of motion values during the seven phases of gait were made between RA and Control ankles using unpaired nonparametric methods. The RA group showed significant differences (pโ<โ0.001) as compared to Controls with prolonged stance time, shortened stride length, increased cadence, and a walking speed that was 80% of Control. Overall, kinematic data in the RA cohort showed significant differences (pโ<โ0.001) in motion for tibial, hindfoot, and forefoot motion as compared to Controls. The effect of RA on segmental foot motion is poorly understood. This study characterized the effect that RA has on motion about the foot and ankle during gait, providing insight into this pathology to improve quantitative assessment, treatment planning, and rehabilitative care. ยฉ 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007