Yoon-Ho K, Sung-In K, Seongjun P, Sung Hwan H, Sun G, Effects of Cervical Extension on Deformation of Intervertebral Disk and Migration of Nucleus Pulposus , PM&R, 9,4, 329-338, 2017
This study on 10 healthy males used MRI to examine the effect of cervical extension on disc deformation and positional change of the nucleus. It found that extension produced anterior migration of the nucleus away from the posterior disc margin and "may have a clinical effect on discogenic neck pain resulting from internal disk disruption"
Auvinen J, Tammelin T, Taimela S, Zitting P, Karppinen J, Neck and shoulder pain in relation to physical activity and sedentary activities in adolescence., Spine, 32:1038-1044, 2007
Cross-sectional study amongst 6000 15-16 year olds to determine activities associated with neck and shoulder pain. About 50% of the girls and 30% of the boys reported some pain, and 5% and 2% respectively reported severe pain in the last 6 months. Pain was associated with high levels of physical activity and with prolonged sitting.
Caneiro JP, O'Sullivan P, Burnett A, Barach A, O'Neill D, Tveit O, Olafsdottir K., The influence of different sitting postures on head/neck posture and muscle activity., Man Ther, 15.54-60, 2009
20 subjects with no symptoms were placed in 3 different sitting postures to investigate influence on head/neck postures and muscle activity. Slump sitting was associated with greater flexion, head protrusion, and increased erector spinae activity compared to upright sitting.
Dunleavy K, Goldberg A, Comparison of cervical range of motion in two seated postural conditions in adults 50 or older with cervical pain., J Man Manip Ther, 21:33-39, 2013
In 36 adults of 50 years or older with neck pain range of movement was compared between their normal and erect sitting postures. Extension, rotation and lateral flexion range was significantly greater in the erect sitting posture, and flexion was significantly less.
Falla D, Jull G, Russell T, Vicenzino B, Hodges P, Effect of neck exercise on sitting posture in patients with chronic neck pain, Phys Ther, 87:408-417, 2007
Comparison of sustained sitting posture for 10 minutes in 58 patients with chronic neck pain and 10 controls, with a distraction computer task. The neck pain group demonstrated a significantly reduced ability to maintain an upright sitting posture and adopted amore forward head posture over time.
Mercer S, Bogduk N, The ligaments and anulus fibrosus of human adult cervical intervertebral discs., Spine, Apr 1;24(7):619-26;, 1998
Anatomical study of 12 adult specimens. Anulus is thick anteriorly, but posteriorly is minimal, reinforced by the posterior longitudinal ligament centrally and virtually absent poster-laterally.
Ordway NR, Seymour RJ, Donelson RG, Hojnowski LS, Edwards WT, Cervical flexion, extension, protrusion, and retraction. A radiographic segmental analysis., Spine, Feb 1;24(3):240-7, 1999
Study into the paradoxical movement pattern of the cervical spine retraction produces lower C extension and upper C flexion, protrusion produces lower C flexion and upper C extension. Full range extension is produced in lower C by extension, but in O-C2 by protrusion; full range flexion is produced in lower C by flexion, but in O-C2 by retraction.
Persson PR, Hirschfeld H, Nilsson-Wikmar L, Associated sagittal spinal movements in performance of head pro- and retraction in healthy women: a kinematic analysis., Manual Therapy, 12:119-125, 2007
Study of the relative contributions of different parts of the spine to produce retraction in 14 healthy women using a computerised video analysis: 60% of movement came from cervical spine, 30% from C7-T4 and 10% from the rest of thoracic spine.
Quek J, Pua YH, Clark RA, Bryant AL., Effects of thoracic kyphosis and forward head posture on cervical range of motion in older adults., Manual Therapy, 18:65-71, 2012
In 51 older adults (mean age 66) with neck pain, with or without referred pain, measurements were taken of neck disability, the thoracic kyphosis, forward head posture and cervical range of movement to determine if there was a relationship between these variables. Greater thoracic kyphosis was significantly associated with more forward head posture; and less forward head posture was significantly associated with greater cervical flexion and rotation. Results support correcting both forward head posture and thoracic kyphosis in those with neck pain.
Skrzypiec D, Pollinyine P, Przybyla A, Dolan P, Adams M, The internal mechanical properties of cervical intervertebral discs as revealed by stress profilometry., Eur Spine J, 16(10):1701-1709, 2007
In this cadaveric study of 46 cervical motion segments from the cervical spine some aspects were the same as the lumbar spine: a hydrostatic nucleus with regions of higher compressive stress concentrated anteriorly in flexion and posteriorly in extension. Some features were unique to cervical spines: a stress gradient across their central region, and stress gradients in the posterior were generally small.
Tuttle N., Do changes within a manual therapy treatment session predict between-session changes for patients with cervical spine pain?, Aust J Physiother, 51(1):43-8, 2004
Response of 29 patients with neck pain to manual therapy in one session and between treatment sessions. Centralisation, decreased pain intensity and increased range of movement within one session all predicted lasting between session improvements.
Yip CHT, Chiu TTW, Poon ATK, The relationship between head posture and severity and disability of patients with neck pain, Manual Ther, 13:148-154, 2008
Comparison of forward head posture among 62 neck pain patients and 52 non-neck patients with a reliable measurement method to measure the craniovertebral angle (ICC 0.98). There was a significant difference between the 2 groups, with neck pain group displaying more forward head posture. The greater the forward head posture the higher pain and disability scores; also forward head posture was associated with older age.