Objective: To evaluate the effects of loss of range of motion (ROM) of the metatarsophalangeal (MTP) joint on the kinematic parameters of walking in rheumatoid arthritis (RA) patients.
Methods: Inclusion of RA patients with inactive disease, no synovitis of the inferior limb and reduced ROM of the MTP joints. Evaluation of the ROM of the MTP dorsal and plantar flexion, and gait analysis using a three-dimensional computerized movement analysis. Calculation of gait parameters and maximal flexion and extension of the hips and knees during walking. Analysis 1 compared the ROM of dorsal and plantar flexion in patients with or without walking pain; 2 compared the gait parameters between patients and controls; 3 investigated a relationship between gait parameters and (i) the ROM of the MTP dorsal and plantar flexion and (ii) the pain at walking; 4 investigated the relationship between the ROM of the MTP dorsal and plantar flexion and maximal flexion and extension of the hip and knee joints during walking.
Results: Nine patients and seven controls were included. The MTP ROM was no different in patients presenting with or without pain at walking. The walking velocity was lower and the stride length shorter in patients than in controls. The walking velocity and the stride length were positively related to the MTP dorsal flexion ROM (r(2)=0.75 and 0.67). There was a negative relationship between maximal flexion of the knee and hips during walking and the underlying MTP dorsal flexion ROM (r(2)=0.67 and 0.54).
Conclusion: In RA patients, reduced MTP dorsal flexion mobility induces changes in the walking parameters, including the kinematics of the overlying lower limb joints. Treatment of an RA-impaired forefoot should focus on MTP mobility as well as on pain.