Postural stability in patients with ankylosing spondylitis.

Area of Science:

• Rheumatology
• Orthopedics
• Biomedical Engineering

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the spine.
• Postural changes, such as increased kyphosis, are common in AS patients.
• The impact of these postural changes on postural stability in AS is not fully understood.

Purpose of the Study:

• To investigate the relationship between postural changes and postural stability in patients with ankylosing spondylitis.
• To compare postural stability in AS patients with varying degrees of postural deformity and healthy controls.

Main Methods:

• A cohort of 64 AS patients and 50 healthy volunteers were assessed.
• AS patients were stratified into two groups based on tragus-to-wall distance (<15 cm and >=15 cm).
• Postural stability was quantified using the Biodex Stability System, measuring Overall Stability Index (OSI), Antero-Posterior Stability Index (APSI), and Medio-Lateral Stability Index (MLSI).

Main Results:

• Statistically significant differences in OSI, APSI, and MLSI were observed across all three groups (AS early stage, AS late stage, and controls).
• Significant differences in MLSI were noted among the AS patient groups.
• Both AS patient groups exhibited significantly poorer postural stability compared to the healthy control group, with more pronounced deficits in the late-stage group.

Conclusions:

• Postural stability is diminished in patients with ankylosing spondylitis, affecting both early and advanced stages of the disease.
• The degree of postural instability is more severe in later stages of AS, correlating with increased kyphosis.
• These findings highlight the functional impact of spinal deformity on balance in AS and suggest potential targets for intervention.