Development of a methodology for studying the bending angle of head and neck

The increment in the use of cell phones and similar products in recent years has caused a growth of the number of young patients with neck pain, headache and shoulders pain, showing early degeneration of the cervical spine, particularly associated to a poor posture adopted when using the cell phone. The purpose of this paper is to propose a methodology to study the flexion angle of the head and neck, evaluating different positions respect to the spine, starting from a standing position (looking forward) to the maximum flexion angle, through a motion analysis system, to be applied in future studies to determinate the maximum flexion angle anatomically allowed to use a cell phone. This movement was made in four cases, from the subject standing up to the subject seated. It was possible to propose a methodology that encompasses both the selection and placement of markers in head and neck, that allows the calculation of the muscle forces and moments and the joint moments, using inverse kinematics and dynamics applied to a musculoskeletal model for each case with specialized open source software (OpenSim).