Trunk position sense, spine posture and static postural sway in axial spondyloarthritis patients: Relation to disease metrology, activity and functional status

Abstract

Aim of the work

This study aimed to compare trunk position sense, spine posture and postural stability, among non-radiographic axial spondyloarthritis (nr-axSpA), ankylosing spondylitis (AS) patients and healthy controls and explore the potential relationships between these parameters and disease-related characteristics.

Patients and methods

Twenty four patients with AS, 23 patients with nr-axSpA, and 24 age and gender-matched healthy controls were participated in this study. A digital inclinometer was used to measure trunk repositioning error (TRE) and spine posture. Postural stability was evaluated with a stabilometric platform. In addition, disease activity, spinal mobility and functional capacity were evaluated with Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Metrology Index and Bath Ankylosing Spondylitis Functional Index, respectively.

Results

The 47 patients mean age was 38.83 ± 9.3 years and were 34 females and 13 males. TRE was higher in AS and nr-axSpA patients compared to control (p < 0.001). AS and nr-axSpA patients presented higher thoracic curvature and lower lumbal lordosis compared to controls (p < 0.05) whereas there was no significant difference between nr-axSpA and AS (p = 0.97). The degree of thoracic curvature was higher in AS compared to nr-axSpA (p = 0.002). Mediolateral stability in eyes closed was significantly higher in AS and nraxSpA than control (p = 0.001). Time since onset of symptoms, which might affect radiographic spinal damage, was significantly associated with TRE in patients with AS (r = 0.703, p = 0.005).

Conclusion

Radiographic status may alter spinal mobility, spine posture and trunk position sense in axSpA patients. Different approaches might need to improve these parameters in different subtypes of axSpA.