SPINE MOVEMENT DURING HALF SQUAT EXERCISE

Abstract

INTRODUCTION .Postural variations of the spine can be studied using radiological technique, but in order to minimize the ionizing radiation we suggested previously to use a non-invasive method. The aim of this study is to describe the movement of the different vertebral segments during half squat exercise. MATEFUAL AND METHOD As described previously external markers are glued to the projecting contours of the spinous processes on 20 voluntary subjects (10 males, 10 females). Markers were implanted on T7, T12, L1, L3, L5 and S1 vertebra levels. This technique was designed to locate angular displacement. Three positions were studied: neutral (vertical trunk, without additional charge), in charge (vertical trunk + 50 kg) and half squat with 50 kg on the shoulders. From the photos were measured, in the sagittal plane, the angular variations at each vertebral segment. RESULTS In standing position the barbell weight induces a general flexion on the cervical and thoracic levels. A verticalization of S1 with an extension of L5 is noticed. In squat position, the main displacement occurs in S1 according to the important movement of the coxo-femoral joint. L5 remains in a constant position. An important flexion is noticed in L3 and L1. T12 seems well fixed. T7 angulation is dependent of head position and of general trunk flexion. DISCUSSION In physical training session emphasis should be laid on the voluntary development of muscles surrounding pelvis, but also of muscles allowing the fixation of thoraco-lumbar joint.