Introduction: The frequency of the appearance of abnormal spinal curvatures is different, depending on the adopted method, the researcher and the adopted norms. The aim of the study is to compare the frequency of the appearance of abnormal spinal curvatures of the body, detected with the mechanical inclinometer and the Moire method, irrespectively of the adopted norms and their influence on the received diagnosis. Material and methods: 96 subjects were involved in the examinations (48 boys and 48 girls at the age of 9). Each tested child had the anterior-posterior spine curvatures examined, with the use of the photogrammetric method and the mechanical inclinometer. Results: Results of measurements of the α , β, γ angles differ significantly in the examined groups (p=0,017). The diagnosis from the photogrametric examination and the inclinometer is characterised by a low unanimity (25,0-37,2%). Similarly in case of comparing the diagnosis from the photogrametric examination, applying two various criteria, the agreement amounts to 9,5-42,3 %, in case of the flat back (93,5%). Conclusions: 1. The frequency of the detection of abnormal spinal curvatures will depend on the applied research method 2. The kind of the detected defect is based on the accepted norms even within one research method.