Theory of Biomechanical Evolution of the Rheumatoid Foot: A Narrative Review.

Background: In patients with rheumatoid arthritis (RA), the pathological progression of lower limb biomechanics is established. Although specific aspects of RA gait patterns have been studied and described, we are aware of no studies of gait pattern compensations over the entire disease course. This study aimed to describe a model that could predict the evolution of lower limb pathomechanics in patients with RA.

Methods: A literature review was conducted of electronic databases (MEDLINE, PEDro, Trip Database, DOAJ, BioMed Central, PLOS clinical trial, ScienceDirect, and CRD York University, AHRQ, NICE, Cochrane Library) to October 3, 2023.

Results: A theory was developed that all people with RA induce or augment gait evolution syndromes following the same biomechanical course. Specifically, we postulate the "rheumatoid equinus syndrome," the "rheumatoid abnormal pronation syndrome" and the "rheumatoid shuffle syndrome," which have never been described before.

Conclusions: A new model of the evolution of gait compensation in RA is proposed. An important challenge of RA is that it increases the risk of ulcerative lesions, falls, pain, fractures, and healthcare costs. The proposed model can be used to reduce morbidity in this patient group by helping to explain and reduce the pain, deformity, and ankylosis of foot RA.