Study of the natural history of the back trunk shape by the use of scoliometer in children aged 5-12 years

The amount of asymmetry of the back trunk shape, that is the existence of a hump, in the general adolescent population during School-screening for sco liosis constitutes one of the strongest indicators for further referral. Th e aim of this study is to map the trunk asymmetry in normal Mediterranean c hildren 5-12 years of age and to determine its natural history. Material an d Method: The readings of scoliometer in 900 children aged 5-12 years (512 boys and 388 girls) were studied. The children were examined at school, dur ing our School-screening program. The bending test was performed both in st anding and sitting forward bending positions using the Pruijs scoliometer, in order to quantify, the existing asymmetry at three areas of interest: in thoracic, thoracolumbar and lumbar area. The severity of asymmetry was def ined in two groups: in the IS' group the scoliometer reading was 1 degrees- 6 degrees, right or left, and in the 2(nd) greater than or equal to 7 degr ees respectively. Seven age groups of children were defined: years ii; 7 le ss than or equal to-years<8; 8 less than or equal to years<9; 9 less than o r equal to years<10; 10 less than or equal to years<11, 11 less than or equ al to years<12 years greater than or equal to 12. The existing symmetries and asymmetries are presented at the three areas of interest, in the two severity groups of asymmetry, in the seven age groups , for the boys and girls. Trunk asymmetries are found in normal children wi th no spinal curve, and they are increasing progressively downwards from th e thoracic to the lumbar area. The more frequently found asymmetries are to the left. The asymmetries to the right are more frequently traced by age. It is shown mat there are more asymmetries in the standing than in the sitt ing position. The traced percentage of symmetry is larger in the sitting po sition, which is after leveling the pelvis and elimination of any leg lengt h inequality effect on back shape. Thus the real trunk asymmetry is reveale d. The differences in percentage in asymmetries in the examination in the t wo positions are probably expressing the existing small leg length inequali ties. These leg asymmetries are either equalized during growth or they faci litate the increasing of trunk asymmetry and probably the pathogenesis of s coliosis with the contribution of other mechanisms, according to our hypoth esis. Another statement that can be implied from this study is that asymmet ries in the form of thoracic or lumbar hump are traced in the thorax or in the loin, without an apparent deformity in the spine (central axis). This m eans that the deforming forces, which begin the asymmetry, do not initiate at the spine, as it is elsewhere claimed. The findings of this study and me above mentioned hypothesis are compatible with the existing Nottingham the ory for palthoganesis of scoliosis. According to our findings we recommend the sitting forward bending position as standard position for examining the rib or loin hump.