THU0633-HPR CORE MUSCLE ENDURANCE IN PATIENTS WITH ANKYLOSING SPONDYLITIS
Authors: D. C. Saraç, S. Bayram, N. G. Tore, F. Sarİ, D. Oskay, A. Avanoğlu Güler, A. Tufan
Journal: Annals of the Rheumatic Diseases (2020)

Background: It is stated that the muscles responsible for spinal stability around the trunk show long-term activity at low intensity in daily life, therefore, endurance insufficiency can cause loss of functionality and spinal stabilization and may induce pain (1). Objectives: The primary purpose of this study was to compare the core muscle endurance of individuals with AS with the core muscle endurance of healthy individuals. The secondary aim of the study was to examine the association between core muscle endurance and balance, disease activity, spinal mobility, functional status, physical activity level and fatigue in individuals with AS. Methods: The research is a cross-sectional study. 41 patients with AS and 40 healthy controls were included in the study. The core muscle endurance of both groups was assessed with trunk extension test, trunk flexion test, right and left side plank tests (2). In addition, in the AS group relationship between core endurance and balance, thoracic kyphosis angle, disease activity, functionality, spinal mobility, physical activity and fatigue was examined. Balance was evaluated with BIODEX Balance Systems and thoracic kyphosis angle was evaluated with a digital inclinometer. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), International Physical Activity Questionnaire (IPAQ), Fatigue Severity Scale (FSS) were used to assess disease activity, functionality, spinal mobility, physical activity and fatigue respectively. Results: Significant differences were found between AS group and control group in core endurance were summarized in Table 1. Additionally, significant relationships were observed between core endurance and all the assessed parameters except thoracic kyphosis angle (p&lt;0.05), (Table 2). Table 1. Comparision of Core Endurance between AS and Control Groups AS Group (n=41 ) Median (IQR ) Control Group (n=40 ) Median (IQR ) P Trunk Extensor Test (sec ) 44.0 (12.0–77.5) 98.25 (63.75-120.0) &lt;0.001 Trunk Flexor Test (sec ) 41.0 (15.0–66.0) 93.0 (55.85-120.0) &lt;0.001 Dominant Side Plank Test (sec ) 29.0 (9.8–62.0) 43.27 (28.57–68.25) 0.046 Non-Dominat Side Plank Test (sec ) 32.0 (10.0–61.32) 41.25 (25.0- 62.37) 0.092 p &gt;0.05, Mann-Whitney U Test; AS: Ankylosing Spondylitis, IQR: Interquartile Range sec: seconds Table.2 Association between core endurance and other parameters Trunk Extensor Test Trunk Flexor Test Dominant Side Plank Test Non-Dominant Side Plank Test Pain (VAS ) -0.535* -0.339* -0.369* -0.203 Stiffness (VAS ) -0.496* -0.234 -0.377* 0.224 Overall Stability Index -0.480* -0.488* -0.725* -0.702* BASFI -0.505* -0.441* -0.562* -0.574* BASMI -0.587* -0.390* -0.613* -0.501* BASDAI -0.468* -0.202 -0.433* -0.345* Kyphosis Angle ( o ) -0.262 -0.287 -0.215 -0.258 IPAQ -0.354* -0.355* -0.523* -0.451* FSS -0.545* -0.445* -0.542* -0.502* *: Spearman’s Correlation Coefficient (rho), p&lt;0.05; VAS: Visual Analog Scale, BASDAI: Bath Ankylosing Spondylitis Disease Activity Index, BASFI: Bath Ankylosing Spondylitis Functional Index, BASMI: Bath Ankylosing Spondylitis Metrology Index, IPAQ:International Physical Activity Questionnaire, FSS: Fatigue Severity Scale Conclusion: Core muscle endurance is lower in patients with AS and it is in relation with many factors regarding the disease. The use of these tests may provide additional information about the patients’ situation for clinicians. References: [1]Özyürek, S., D. Bayraktar, and A. Genç, Are the alterations in body posture related to decreased trunk muscle endurance in healthy young adults? Journal of back and musculoskeletal rehabilitation, 2018. 31(3): p. 431-436. [2]McGill, S.M., Low back stability: from formal description to issues for performance and rehabilitation. Exercise and sport sciences reviews, 2001. 29(1): p. 26-31. Disclosure of Interests: None declared