Static Foot Posture and its Relationship with Clinical Variables in Axial Spondyloarthritis Patients Participating in Leisure-time Activities

Objective: This study aimed to assess static foot posture in patients with axial spondyloarthritis (axSpA) and to examine its association with clinical and postural variables. Materials and methods: Forty-one patients with axSpA and 41 age- and sex-matched healthy controls were included. Static foot posture was evaluated using a podoscope combined with three-dimensional scanning and computerized analysis software. Spinal posture was measured with a digital inclinometer, and spinal mobility was assessed using the Bath Ankylosing Spondylitis Metrology Index (BASMI). Disease activity, functional status, and quality of life were evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Ankylosing Spondylitis Quality of Life questionnaire (ASQoL), respectively. Results: No significant difference was found between groups regarding the Arch Index (AI) (p = 0.143). However, non-neutral foot postures, including pronated and supinated patterns, were significantly more frequent in the axSpA group (p < 0.001). Lumbar lordosis differed significantly between patients and healthy controls (p < 0.001). Subgroup analysis demonstrated that pain severity was significantly higher in patients with pes planus and pes cavus compared with those with neutral foot posture (p = 0.035 and p = 0.045, respectively). Additionally, AI was significantly associated with pain severity at rest and during activity. Conclusion: Altered static foot posture is common in axSpA. Foot involvement and its functional implications should be evaluated as part of routine clinical assessment, irrespective of disease activity.