In a comprehensive literature review, Palmer and Smedley found moderate evidence of an association between neck-shoulder pain with palpation tenderness and work related:
· repetitive shoulder motion
· sustained or frequent neck flexion with repetitive shoulder motion
· static loading of the neck-shoulder musculature in combination with repetition and sustained/frequent neck flexion
The authors also found a limited or inconclusive relationship between neck-shoulder pain with palpation tenderness and work related:
· static loading of the neck-shoulder musculature
· repetitive hand-wrist motion
· sustained or frequent neck flexion in the absence of repetitive shoulder motion
· static loading of the neck-shoulder musculature
· force in the absence of repetitive motion
· high job mental demands
· low control over work
· low social support at work
· job mental strain (high mental demands/low control/low social support)
Insufficient evidence was found to support an association between neck-shoulder pain with palpation tenderness and work related:
· rest breaks
· lifting, carrying and manual handling
· high estimated metabolic energy expenditure
· hand-arm vibration
· whole-body vibration
At the request of the Danish National Board of Industrial Injuries, an investigation of the scientific evidence involving work related chronic neck-shoulder pain (cervicobrachial syndrome) was conducted. Primary studies involving neck-shoulder pain identified by Kuorinka and Forcier (Work-related musculoskeletal disorders, 1995), Bernard and Fine (Musculoskeletal Disorders and Workplace Factors, 1997), Buckle and Devereux (Work-related neck and upper limb musculoskeletal disorders, 1999), and Ariëns (Work-related risk factors for neck pain, 2001) were reviewed along with more recent publications found through a search using MEDLINE, Embase BIDS, and Psychinfo.
Criteria for study inclusion in the review consisted of:
1) Case study definition consisting of:
v one or more symptoms (neck or neck-shoulder girdle pain with or without radiation)
v one or more physical signs determined through clinical examination that supported subjective symptoms
2) Evaluation of physical exposures such as:
v frequent or rapid movement of the shoulders, arms, or upper limbs
v repeated or static neck flexion
v static loading (sustained isometric contraction) of the neck/shoulder region
v heavy physical work
v forceful gripping
v precision work
v hand-arm vibration
3) Evaluation of personal and occupational psychosocial factors such as:
v high mental demands, workload or pace of work
v limited work control/decision making
v job strain (combination of high demands and low control)
v limited social support from co-workers or management
v task boredom
v job satisfaction
While 136 primary research studies were identified, 115 were not further evaluated due to shortcomings relative to the defined inclusion principles.
A “quality rating” was given to each research paper based on multiple factors including study design, confounders/effect modifiers, population size, outcomes studied, and estimates of effect.
Further, the degree of causal association evidence between an exposure and an outcome was assessed based on “strength, consistency, quality, and amount of evidence against specific formulations of outcome and exposure” as per the Scientific Committee of the Danish Society of Occupational and Environmental Medicine.
The volume of quality studies was considered small. Of the 21 relevant primary reports, 2 were considered excellent (Andersen et al., 2003; Andersen et al., 2002) while 4 were thought to be useful despite important limitations. Five studies were deemed moderately informative while 10 were labeled limited.
Palmer and Smedley note some inconsistency in their findings relative to the Bernard and Fine review (1997). The authors explain these differences resulted from using more stringent criteria in their review.
Reservations effecting of this research include:
1. Acknowledgement by the authors that it is very difficult to accurately assess risk factor exposure of an individual:
v the definition of select risk factors vary – repetition may be measured by frequency, duration, rest breaks, range/direction of motion
v it is not uncommon for multiple risk factors to co-exist such as repetition, boredom, low job control; defining the contribution of the exposure to the outcome is murky
v different body regions may receive the exposure (i.e., hand, wrist, elbow, shoulder, neck, or any combination of these); risk factor impact given there may be select/multi body part involvement can be lead to confusing outcomes
v studies tend to evaluate the exposure of a sample group which then becomes averaged and interpreted as the exposure of a larger group
2. Only research published in peer-reviewed journals and written in English were assessed.
Article Title: Work relatedness of chronic neck pain with physical findings – a systematic review
Publication: Scandinavian Journal of Work, Environment and Health 33(3): 165-191, 2007
Authors: K T Palmer and J Smedley
This article originally appeared in The Ergonomics Report™ on 2007-08-02.