ABSTRACT
Objective To evaluate and describe the changes of core muscle groups based on DAVID spine biomechanics training system in ankylosing spondylitis (AS) patients.Methods The clinical data of 100 patients of AS and 31 healthy controls were collected.Clinical symptoms,Bath ankylosing spondylitis disease activity index (BASDAI),Bath ankylosing spondylitis function index (BASFI),Bath ankylosing spondylitis measurement index (BASMI),ankylosing spondylitis disease activity (ASDAS),and simultaneous detection of DAVID spine biomechanics training system,simple core muscle fitness test:Eight-grade abdominal bridge,PLANK exercise (fiat support),Abdominal static muscle endurance test,Back static muscle endurance test were compared using t-test analysis and spearman correlation analysis.Results ① Between AS and healthy male control o group,there were significant differences of spinal mobility in forward flexion,right rotation,left rotation (42±13 vs 48±1,52±14 vs 69±12,52±13 vs 58±11;all P values ＜0.05);and significant differences of spinal muscle strength in forward bending force,right rotation force,left rotation force,fight bending force (103±42 vs 146±17,87±34 vs 104±13,80±35 vs 101±13,161±55 vs 186±19;all P values ＜0.05),and significant differences in the left/right rotational force (1.17±0.21 vs 1.02±0.111,P＜0.05) of spine balance strength comparison.② Between AS and healthy controls of female group,there were differences in forward bending force (49±23 vs 77±10,P＜0.05) of spinal muscle strength;and significant differences in forward bending/backward extension strength,left and right rotation strength (0.32±0.11 vs 0.58±0.21,1.29±0.21 vs 1.03±0.11,all P values ＜0.05) of spine balance strength;③ In AS group,the spinal mobility was correlated with age (Rear extension r=-0.28,right flexion r=-0.268,left flexion r=-0.404,right rotation r=-0.367,left rotation r=-0.235;all P values ＜0.05),course of disease (Rear extension r=-0.354,forward flexion r=-0.283,right flexion r=-0.204,left flexion r=-0.284,right rotation r=-0.339,left rotation r=-0.23;all P values ＜0.05),body mass index (BMI) (Rear extension r=-0.23,forward flexion r=-0.288,right flexion r=-0.22,left flexion r=-0.201,right rotation r=-0.26,left rotation r=-0.29;all P values ＜0.05),sacroiliac joint stage(Rear extension r=-0.375,forward flexion r=-0.446,right flexion r=-0.331,left flexion r=-0.367,right rotation r=-0.368,left rotation r=-0.314;all P values ＜0.05) and BASDAI(Rear extension r=-0.381,forward flexion r=-0.374;all P values ＜0.05).Spinal muscle strength was correlated with gender (Posterior extensor force r=0.344,flexor force r=0.507,right rotation force r=0.376,left rotation force r=0.399,right flexion force r=0.433,left flexion force r=0.445;all P values ＜0.05);the left/right spine rotation strength was correlated with gender (r=0.271,P＜0.05).④ In the simple core muscle fitness test,eight-grade abdominal bridge was correlated with spinal muscle strength (Rear extension force r=0.234,right rotation r=0.290,left rotation r=0.219,right flexion r=0.35,left flexion r=0.327;all P values ＜0.05);PLANK exercise was correlated with spinal muscle strength (Rear extension force r=0.234,right rotation r=0.290,left rotation r=0.219,right flexion r=0.35,left flexion r=0.327;all P values ＜0.05);abdominal static muscle endurance test was correlated with forward flexion strength (r=0.341,P＜0.05);back static muscle endurance test was correlated with spinal mobility (Rear extension r=0.262,forward flexion r=0.23,right rotation r=0.455,left rotation r=0.426,right flexion r=0.387,left flexion r=0.46;all P values ＜0.05);correlated with spine strength (right flexion r=0.256,left flexion r=0.272;all P values ＜0.05).Conclusion Compared with healthy people,AS patients have decreased activity,strength and balance of spinal core muscle.There are significant decline in spinal mobility and muscle strength of male AS patients and muscle imbalance of female AS patients.Simple core muscle fitness test could be used in clinic to measure the changes of AS patients'core muscle group.