THE RELATIONSHIP BETWEEN POSTURAL CHANGES AND TRUNK MUSCLE ENDURANCE IN CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS

Background: Body posture is defined as relative biomechanical alignmentof body’s head, trunk, and extremities as well as position of the body inthe space. Body posture might be altered due to different musculoskeletalpathologies. Juvenile Idiopathic Arthritis (JIA) is a chronic inflammatory diseasecharacterized by musculoskeletal problems including bone and musclegeometry alterations which may lead a deteriorated posture. However, it isnot known whether trunk muscle endurance is associated with body posturein children with JIA.Objectives: To investigate the relationship between postural changes and trunkmuscle endurance in children with JIA.Methods: Thirty-four children (eighteen female, sixteen male) were included inthe study. Postural changes were assessed by a three-dimensional evaluationsystem (PosturePrint System, Biotonix, Canada). The system provides PostureIndex (PI) score which is a composite score from three postural regions includinghead, ribcage, and pelvis. Higher PI scores indicate a more deterioratedposture. Biering–Sørensen Test (BST), Flexor Endurance Test (FET), LateralEndurance Test (LET) were used to assess trunk muscle endurance, and StaticScapular Endurance Test (SSET) were used to assess scapular muscle endurance.Spearman Rank Correlation test was employed to determine the possiblerelationships.Results: Enthesitis related arthritis was the most common JIA subtype in thestudy (38.2%) followed by oligoarthritis (26.5%), polyarthritis (20.6%), and systemicarthritis (14.7%). Significant negative correlations were detected betweenSSET and PI-head score (rho= -0.467, p=0.005), SSET and PI-ribcage score(rho= -0.381, p=0.026); FET and PI-head score (rho= -0.469, p=0.005); LET andPI-head score (rho= -0.441, p=0.009).Conclusion: These results indicated that postural displacements of head andribcage are linked with decreased trunk and scapular muscle endurance in childrenwith JIA. Exercise and physical activity programs targeting muscle endurancemay result improvements in posture in these children.