The 4DBODY system as a new tool for chest mobility assessment in patients with ankylosing spondylitis.

Introduction: Ankylosing spondylitis (AS) is a chronic inflammatory, progressive disease, which leads to deterioration of chest and spine mobility and decrease of physical capacity with abnormal chest movement patterns. We aimed to assess the usefulness of the 4DBODY technology for evaluation of the effectiveness of AS treatment.

Material and methods: The 4DBODY technology was assessed on single AS patient with axial involvement. The patient was examined twice, before and after 14 days of rehabilitation. Physiotherapeutic and plethysmographic examinations were used, as well as angular measurement of spine curvatures and measurement of chest mobility. Chest activity measured using the 4DBODY system and the quality of movement were visualized.

Results: There was observed an increase of chest mobility from 18 mm to 27.9 mm (up 55%) in the 4DBODY system measurement. The quality of the chest movement also improved, the required phases of inspiration were synchronized. The angular position of the spine has also changed. The chest expansion improved from 25 mm to 50 mm measured on the level of the fourth intercostal space and from 30 mm to 50 mm at the Th10 level. Inspiratory and expiratory muscle strength increased respectively from 80% to 93% and from 46% to 86% of the predicted values. Total airway resistance (Rtot) - increase from 59% to 67%, whereas functional residual capacity (FRC) and total lung capacity (TLC) did not change significantly.

Conclusions: The new 4DBODY technology was found to be an effective method of examination and assessment of the effectiveness of rehabilitation of patients with AS.