Trunk and cervica muscles activity during straightening of cervicothoracic spine segment provoked by external rotation of the arm
Abstract
A relaxed standing is natural, but it leads to a back pain. Erect posture was provoked by an external humeral rotation and adduction of the shoulder that resulted in increased activation of the trunk muscles.
The stabilized trunk led to the upright posture of the cervical-thoracic spine. The kinematics of the spine and the inclination of the pelvis were measured in the sagittal plane with a motion analysis system.
The trunk and neck muscle activity was measured with the electromyography. Six subjects without pathology of the pelvis, shoulder girdle and spine were recruited in this pilot study.
The possible correlation between the postural changes and the changes of the muscle activity was determined: the tilt of the pelvis could correlated with the internal oblique, quadratus lumborum and external oblique posterior part, the change of the shape of the cervical-thoracic spine could related with the erector spinae in the thoracic region.