ABSTRACT
CONTENTS Introduction ...........................................................................................................87 5.1 Head Inclination ..........................................................................................89 5.2 Neck Flexion/Extension .............................................................................91 5.3 Recommended Gaze Inclination for VDU Operation .........................100 5.4 Neck Twisting.............................................................................................103 Summary ..............................................................................................................104 References.............................................................................................................105
On the basis of a systematic literature review, Ariëns (2001) stated that neck pain is a major musculoskeletal health problem in modern society, occurring in many different occupational groups. Furthermore, it was found that neck posture is a risk factor for neck pain. In this chapter it will be shown that the earlier studies reporting the effects of head and neck posture (e.g., neck load, health complaints) focus solely on head inclination (i.e., the amount of deviation from the upright posture or from the vertical; see Figure 5.1 and Section 5.1). This can be seen as a measure of musculoskeletal load, an equivalent of the force delivered by the neck muscles to counteract the gravitational force on the head. It should be noted that the way of measuring head inclination varies among studies, with some using reference points on the skull only while others also include the whole or parts of the cervical spine in their definition. Furthermore, some researchers measure head inclination with respect to the upright head posture, while others measure head inclination with respect to the vertical. In more recent years, attention has also been given to another posture variable that was seen as a possible risk
