Clinical and biomechanical factors associated with falls and rheumatoid arthritis: baseline cohort with longitudinal nested case–control study.

Objective To identify the clinical and biomechanical characteristics associated with falls in people with RA. Methods A total of 436 people ≥60 years of age with RA completed a 1 year prospective survey of falls in the UK. At baseline, questionnaires recorded data including personal and medical history, pain and fatigue scores, health-related quality of life (HRQoL), physical activity and medication history. The occurrence of falls wasmonitored prospectively over 12 months by monthly self-reporting. A nested sample of 30 fallers (defined as the report of one or more falls in 12 months) and 30 non-fallers was evaluated to assess joint range of motion (ROM), muscle strength and gait parameters. Multivariate regression analyses were undertaken to determine variables associated with falling. Results Compared with non-fallers (n  = 236), fallers (n  = 200) were older (P  = 0.05), less likely to be married (P  = 0.03), had higher pain scores (P  < 0.01), experienced more frequent dizziness (P  < 0.01), were frequently taking psychotropic medications (P  = 0.02) and reported lower HRQoL (P  = 0.02). Among those who underwent gait laboratory assessments, compared with non-fallers, fallers showed a greater anteroposterior (AP; P  = 0.03) and medial-lateral (ML) sway range (P  = 0.02) and reduced isokinetic peak torque and isometric strength at 60° knee flexion (P  = 0.03). Fallers also showed shorter stride length (P  = 0.04), shorter double support time (P  = 0.04) and reduced percentage time in swing phase (P  = 0.02) and in knee range of motion through the gait cycle (P  < 0.01). Conclusion People with RA have distinct clinical and biomechanical characteristics that place them at increased risk of falling. Assessment for these factors may be important to offer more targeted rehabilitation interventions. [ABSTRACT FROM AUTHOR]