Effect of Two Contrasting Types of Physical Exercise on Chronic Neck Muscle Pain
From: Arthritis & Rheumatism Vol. 59, No. 1, January 15, 2008, pp 84–91
The prevalence of neck muscle pain and neck strain has steadily increased and especially pain from the descending part of the trapezius muscle has been associated with monotonous work tasks such as computer work. Physical exercise is generally recommended as treatment, but it is unclear which type of training is most effective. Our objective was to determine the effectiveness of specific strength training of the painful muscle versus general fitness training without direct involvement of the painful muscle (leg bicycling) on work-related neck muscle pain.
Musculoskeletal disorders comprise one of the most common and costly public health problems in North America and Europe today, with an estimated cost between 0.5% and 2% of the Gross National Product. In particular, the prevalence of neck pain has been steadily increasing through the past 2 decades, and is now second to back pain, the most common musculoskeletal disorder. More than half of all adults have experienced neck pain during the past 6 months, and women are more likely than men to develop and suffer from persistent neck pain. Still actively employed, these women experience sensations of localized muscle pain, tenderness at palpation, stiffness, and constant muscle fatigue. In particular, computer work has been associated with neck symptoms, and more specifically pain from the descending part of the trapezius muscle, or trapezius myalgia, is frequent in women engaged in repetitive and monotonous work tasks. Based on the prevailing literature, it is plausible that sustained overload of the smallest motor units of the muscle leads to homeostatic disturbances and eventually trapezius myalgia.
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From: NIOSH Publication No. 97-141 Musculoskeletal Disorders and Workplace Factors
Definition of Posture for Neck and Neck/Shoulder Pain
We included those articles that mentioned neck posture or head postures, adverse or extreme head or neck postures, or static postures of the head and/or neck.
Studies Reporting on Posture as a Work Factor for Neck and Shoulder Pain
We included 31 studies of the association between extreme or static posture and neck and neck/shoulder pain, including TNS. Studies usually focused on the different prevalences of neck symptoms and/or physical findings in workers in occupations or tasks requiring some combination of forceful, repetitive movements, and extreme or static postures of the upper extremity, and compared them to workers in occupations without those requirements.
Twenty-seven studies that considered extreme or static posture found a statistically significant positive association between posture and neck or neck/shoulder pain; three had non-significant findings, 13 studies had estimations of risk. Eleven studies did not report their results in terms of ORs or PRRs; of these, all but one found a significant relationship.
Studies Meeting the Four Evaluation Criteria
Of the 31 studies evaluating neck postures and neck pain, the four investigations mentioned above [Ohlsson et al. 1995; Jonsson et al. 1988; Kilbom and Persson 1987; Kilbom et al. 1986] fulfilled the four evaluation criteria. Three of these studies [Jonsson et al. 1988; Kilbom et al. 1986; Kilbom and Persson 1987], dealt with the same cohort; female electronics workers followed for 3 successive years. These studies found significant association between posture variables and neck pain; however, none used methods that reported ORs.
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Neck Exercise for Sitting Posture With Chronic Neck Pain
From: Physical Therapy Vol. 87, No. 4, April 2007, pp. 408-417
Poor sitting posture has been implicated in the development and perpetuation of neck pain symptoms. This study compares change in cervical and thoracic posture during a distracting task between subjects with chronic neck pain and control subjects and the effects of 2 different neck exercises on the ability of people with neck pain to maintain an upright cervical and thoracic posture during this task.
Fifty-eight subjects with chronic, nonsevere neck pain and 10 control subjects participated in the study.
Change in cervical and thoracic posture from an upright posture was measured every 2 minutes during a 10-minute computer task. Following baseline measurements, the subjects with neck pain were randomized into one of two 6-week exercise intervention groups: a group that received training of the craniocervical flexor muscles or a group that received endurance-strength training of the cervical flexor muscles. The primary outcomes following intervention were changes in the angle of cervical and thoracic posture during the computer task.
Results : Subjects with neck pain demonstrated a change in cervical angle across the duration of the task consistent with a more forward head posture. No significant difference was observed for the change in cervical angle across the duration of the task for the control group subjects. Following intervention, the craniocervical flexor training group demonstrated a significant reduction in the change of cervical angle across the duration of the computer task.
This study showed that people with chronic neck pain demonstrate a reduced ability to maintain an upright posture when distracted. Following intervention with an exercise program targeted at training the craniocervical flexor muscles, subjects with neck pain demonstrated an improved ability to maintain a neutral cervical posture during prolonged sitting.
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Intervertebral Disc: Anatomy Physiology Pathophysiology Treatment
From: Pain Practice, Volume 8, Issue 1, 2008 18–44
Back pain is strongly associated with degeneration of the intervertebral disc. Disc degeneration, although in many cases asymptomatic, is also associated with sciatica and disc herniation or prolapse. It alters disc height and the mechanics of the rest of the spinal column, possibly adversely affecting the behavior of other spinal structures such as muscles and ligaments. In the long term, it can lead to spinal stenosis, a major cause of pain and disability in the elderly; its incidence is rising exponentially with current demographic changes and an increased aged population.
The loss of proteoglycan in degenerate discs has a major effect on the disc’s load-bearing behavior. With loss of proteoglycan, the osmotic pressure of the disc falls and the disc is less able to maintain hydration under load; degenerate discs have a lower water content than do normal age-matched discs, and when loaded they lose height and fluid more rapidly: the discs tend to bulge. Loss of proteoglycan and matrix disorganization has other important mechanical effects; because of the subsequent loss of hydration, degenerated discs no longer behave hydrostatically under load. Loading may thus lead to inappropriate stress concentrations along the endplate or in the annulus; the stress concentrations seen in degenerate discs have also been associated with discogenic pain produced during discography.
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Low Back Pain in Relation to Lumbar Disc Degeneration
From: Spine. 25(4):487-492, February 15, 2000
A Cross-sectional magnetic resonance imaging (MRI) study to study the relation of low back pain to disc degeneration in the lumbar spine.
Controversy still prevails about the relationship between disc degeneration and low back pain. Classification of disc degeneration and symptoms varies, hampering comparison of study results.
Subjects comprised 164 men aged 40-45 years-53 machine drivers, 51 construction carpenters, and 60 office workers. The data of different types of low back pain, individual characteristics, and lifestyle factors were obtained from a questionnaire and a structured interview. Degeneration of discs L2/L3-L5/S1 (dark nucleus pulposus and posterior and anterior bulge) was assessed with MRI.
An increased risk of low back pain (including all types) was found in relation to all signs of disc degeneration. An increased risk of sciatic pain was found in relation to posterior bulges, but local LBP was not related to disc degeneration. The risks of low back pain and sciatic pain were strongly affected by occupation.
Low back pain is associated with signs of disc degeneration and sciatic pain with posterior disc bulges. Low back pain is strongly associated with occupation.
Evaluation and Treatment of Posterior Neck Pain in Family Practice
From: J Am Board Fam Pract 2004;17:S13–22
The human neck is a complex structure that is highly susceptible to irritation. In fact, 10% of people will have neck pain in any given month. Potential pain generators include bones, muscles, ligaments, facet joints, and intervertebral discs. Almost any injury or disease process within the neck or adjacent structures will result in reflexive protective muscle spasm and loss of motion. Gradual collapse of the intervertebral discs and degeneration of the facet joints is a universal part of the aging process and, in some people, can lead to nerve or spinal cord impingement. Further, neck mobility is so important to normal human functioning that any disruption in its normal function is quickly noticed.
Neck pain is an extremely common but nonspecific symptom. In a population-specific study, Cote et al found that 66% of Saskatchewan adults experienced neck pain at some point in their lifetimes, 54% in the most recent 6 months. The prevalence of neck pain at any point in time is approximately 9%. Prevalence increases with age and is higher in women than in men. Neck pain accounts for almost 1% of all visits to primary care physicians in the United States.
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