Related Experiment Video
Updated: Jul 27, 2026
07:09
In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint
Published on: March 7, 2014
Head posture and loading of the cervical spine
1Institute for Occupational Ergonomics, University of Nottingham, UK. e.n.corlett@nottingham.ac.uk
Applied Ergonomics
|September 19, 2002
Summary
Looking down increases cervical spine load, causing significant spinal shrinkage. This challenges current textbook recommendations for head and eye posture.
Area of Science:
- Occupational Health
- Biomechanics
- Ergonomics
Background:
- Previous calculations suggested that downward gaze angles increase cervical spine loading compared to horizontal gaze.
- Ergonomic guidelines often recommend specific gaze angles without sufficient empirical validation regarding spinal load.
Purpose of the Study:
- To empirically measure the effects of different gaze angles on spinal length.
- To assess the impact of prolonged downward gaze on spinal loading in a seated posture.
Main Methods:
- Seven subjects participated in precision stadiometer tests.
- Spinal length changes were measured after 1 hour of exposure to controlled sitting postures with varying gaze angles (horizontal, 20° below horizontal, 40° below horizontal).
Main Results:
- Significant differences in spinal shrinkage were observed between horizontal gaze and gaze angles 20° and 40° below the horizontal.
- Increased spinal shrinkage indicates greater spinal loading under downward gaze conditions.
Conclusions:
- Prolonged downward gaze significantly increases cervical spine loading, evidenced by spinal shrinkage.
- Current textbook recommendations for gaze angles may not adequately protect against increased spinal loading and should be re-evaluated.
More Related Videos
07:30A Test Bed to Examine Helmet Fit and Retention and Biomechanical Measures of Head and Neck Injury in Simulated Impact
Published on: September 21, 2017
07:12Clinical Efficacy of an Innovative Multidimensional Traction Therapy in Moderate Adolescent Idiopathic Scoliosis
Published on: February 10, 2026
Related Concept Videos
01:11Anatomical Positions
In anatomy, several standard anatomical positions are used as references for describing the position and orientation of different body parts. These positions help provide a common frame of reference when discussing anatomical structures. The anatomical position is the standard reference point for describing the body's position and orientation. In this position:
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...
01:14Cranial Bones: Superior and Posterior View
The superior view of the cranium shows the frontal and paired parietal bones.
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
01:16Vertebral Column: Regions and Curvature
The vertebral column or spine is a flexible column that supports the head, neck, and body and allows for their movements. It also protects the spinal cord.
Regions of the Vertebral Column
In an adult, the spine is subdivided into five regions: the cervical, the thoracic, the lumbar, the sacral, and the coccygeal region. The spine initially develops as a series of 33 vertebrae; after 20 years of age, the nine bones in the sacral region, five sacral, and four coccygeal bones fuse to form the...
Regions of the Vertebral Column
In an adult, the spine is subdivided into five regions: the cervical, the thoracic, the lumbar, the sacral, and the coccygeal region. The spine initially develops as a series of 33 vertebrae; after 20 years of age, the nine bones in the sacral region, five sacral, and four coccygeal bones fuse to form the...
01:28Articulations of the Vertebral Column
In addition to being held together by the intervertebral discs, adjacent vertebrae also articulate with each other at synovial joints formed between the superior and inferior articular processes called zygapophysial joints (facet joints). These are plane joints that provide for only limited motions between the vertebrae. The orientation of the articular processes at these joints varies in different regions of the vertebral column and serves to determine the types of motions available in each...
01:19Muscles that Move the Head
The muscles that move the head are a dynamic and complex group of structures that work together to facilitate a wide range of head movements, including rotation, flexion, extension, and lateral bending.
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
01:16Eccentric Axial Loading in a Plane of Symmetry
Eccentric axial loading occurs when an axial load is applied away from the centroidal axis of a structural member. This scenario is common in engineering, where structural elements may not be directly aligned due to various design or functional requirements.