Pain intensity and associated disability at the neck/shoulder-low back regions were reduced when a workplace intervention (engineering and administrative controls) or when a combination educational worksite intervention/workplace intervention was applied to 492 subjects from 125 occupations over a four to six year time period. However, the degree of improvement was not significant when compared to a control group with no interventions according to Grooten et al. Further, those who received only educational worksite interventions had a poorer outcome than those with no interventions.
Study Design
Subjects
The study involved 294 women/198 men with a mean age of 40.6 years and were professionally divided as 54% blue collar, 14% white collar in lower positions, 24% white collar in medium/higher positions, and 8% other (i.e., self-employed).
These volunteers sought treatment for neck/shoulder or low back pain during 1994 or 1997 (baseline years) however, did not receive care during the period six months prior to the 2000-2001 follow-up assessment.
Also, subjects worked at least 17 hours per week both at baseline and at follow-up.
Study Set Up
At baseline (1994 or 1997), the subjects completed a questionnaire covering gender, age, pain intensity in the neck/shoulder and low back, pain-related disability in the neck/shoulder and low back, incidence of other disease/disorders, work-related psychosocial exposure, and work-related biomechanical exposure.
A follow-up postal questionnaire sent in 2000-2001 asked:
· the same baseline questions relative to pain intensity in the neck/shoulder and low back
· the same baseline questions relative to pain-related disability in the neck/shoulder and low back
· seven questions regarding workplace ergonomic interventions
· specific inquires relative to treatment sought during the follow-up period
From the workplace ergonomic intervention questions, the subjects were placed into one of four groups:
1) No ergonomic interventions; 61.4% of the subjects.
2) Educational worksite interventions – the authors defined this as methods to increase the capacity of the individual to better fit the work physical demands such as providing ergonomic information, different work technique training or job training programs (neck/back school); increasing the workers’ physical capability; 10.2% of the subjects.
3) Workplace interventions – the authors defined this as strategies to adjust the workload to better fit the capacity of the individual through technical aids or reorganization of work tasks; optimizing the workload relative to the individual; 19.3% of the subjects.
4) Combined workplace and educational worksite interventions; 9.1% of the subjects.
Control Group
Subjects that received no ergonomic interventions were considered as the reference group.
Key Outcome Measurements
Neck/shoulder and/or low back pain intensity were dependent variables. Subjects were asked to rate on a scale from 0 (“no pain”) to 10 (“pain as bad as it could be”):
· current pain
· worst pain during the previous six months
· average pain during the previous six months
The mean of these six scores became the subject’s pain intensity score.
Disability due to neck/shoulder and/or low back pain was also a dependent variable. Subjects were asked to rate on a scale from 0 (“not affected at all”) to 10 (“impossible to continue with these activities”) how much during the prior six months the pain had effected:
· everyday activities
· social and family activities
· ability to work (including household chores)
The mean of these six scores became the subject’s pain-related disability score.
Changes in these scores relative to the type of intervention were the outcome of interest. Eighteen potential confounders were evaluated.
Other Findings
Group |
Pain Intensity Score |
Pain-Related Disability Score |
||
|
|
Baseline |
Follow up |
Baseline |
Follow up |
|
No Intervention |
3.0 |
2.3 |
1.5 |
0.8 |
|
Educational Intervention |
3.2 |
3.2 |
1.3 |
1.3 |
|
Worksite Intervention |
3.3 |
2.2 |
1.7 |
0.7 |
|
Both Educational and Worksite Intervention |
3.8 |
3.3 |
2.3 |
1.9 |
Table 1: Median study score values.
Subjects had a moderately low mean baseline pain intensity score of 3.3.
Study Limitations
Reservations effecting of this research include:
1. Due to the combination of long time duration (4 to 6 years) with self reporting, errors could have occurred as to type of intervention the subject received.
2. Subjects could have experienced memory challenges regarding the intensity and impact of their pain relative to the prior six months.
3. Details regarding the type of ergonomic engineering or administrative controls applied were not defined. It is unknown if the interventions were geared to the specific disorders.
4. Details regarding the nature of the educational intervention were not described. If not orientated to the subject’s area of pain, the value of the training could be questionable.
5. It is not indicated who performed the interventions – a trained individual would likely have a different impact than local management.
6. The control group was relatively large (61.4%) compared to the three other groups in this study (which made up the remaining 38.6%).
Article Title: The effect of ergonomic intervention on neck/shoulder and low back pain
Publication: Work 28: 313-323, 2007
Authors: W J A Grooten, M Mulder, and C Wiktorin
This article originally appeared in The Ergonomics Report™ on 2007-08-02.