Change in Gait Deviation Index after anti-tumour necrosis factor-α treatment in individuals with rheumatoid arthritis: a pilot study

Abstract

Objectives: Anti-tumour necrosis factor-alpha (TNF-α) inhibitors provide fast, effective resolution of rheumatoid arthritis (RA) inflammation. In this study we aimed to quantify the impact of TNF-α treatment on gait dynamics.

Method: The sample comprised 16 subjects [11 female, median age 56 (range 48–66) years, median disease duration 9.5 (range 4.6–20.6) years] with RA who met the American College of Rheumatology (ACR) criteria, had lower extremity involvement, did not use walking aids, and had started TNF-α treatment within 1 week of baseline gait analysis. Gait analysis focused on three-dimensional (3D) lower extremity joint kinematics, kinetics, time and distance parameters. The Gait Deviation Index (GDI) and GDI-Kinetic were calculated. Data on gait, disease activity, and physical disability were collected at baseline and at 3.5 months.

Results: Following treatment with TNF-α, statistically significant improvements were found in disease activity [using the 28-joint Disease Activity Score based on C-reactive protein (DAS28-CRP); median difference (m_d) = 2.3, p < 0.01], physical disability [Health Assessment Questionnaire (HAQ) m_d = 0.4, p < 0.01], and pain during walking [visual analogue scale (VAS) m_d = 11.0, p < 0.05]. Reductions in gait deviations were noted (GDI m_d = 3.7, p = 0.04; GDI-Kinetic m_d = 4.1, p = 0.05) along with reductions in dimensionless time and distance parameters. A moderate to good negative correlation existed between baseline GDI and GDI change scores (r_s = –0.7, p < 0.01).

Conclusions: Treatment with TNF-α improved gait dynamics in adults with RA. Significant gait deviations were, however, still present after treatment. In this study, GDI and GDI-Kinetic scores appeared to be useful outcome measures to quantify changes in gait deviations after this intervention.

Acknowledgements

Funding for this study was provided by the research foundations Promobilia Karolinska Institutet Foundations and Funds and the developmental foundation of the footwear industry.