A prospective study of work perceptions and psychosocial factors affecting the report of back injury.

A longitudinal, prospective study was conducted on 3,020 aircraft employees to identify risk factors for reporting acute back pain at work. The premorbid data included individual physical, psychosocial, and workplace factors. During slightly more than 4 years of follow-up, 279 subjects reported back problems. Other than a history of current or recent back problems, the factors found to be most predictive of subsequent reports in a multivariate model were work perceptions and certain psychosocial responses identified on the Minnesota Multiphasic Personality Inventory (MMPI). Subjects who stated that they "hardly ever" enjoyed their job tasks were 2.5 times more likely to report a back injury (P = 0.0001) than subjects who "almost always" enjoyed their job tasks. The quintile of subjects scoring highest on Scale-3 (Hy) of the MMPI were 2.0 times more likely to report a back injury (P = 0.0001) than subjects with the lowest scores. The multivariate model, including job task enjoyment, MMPI Scale-3, and history of back treatment, revealed that subjects in the highest risk group had 3.3 times the number of reports in the lowest risk group. These findings emphasize the importance of adopting a broader approach to the multifaceted problem of back complaints in industry and help explain why past prevention efforts focusing on purely physical factors have been unsuccessful.

A prospective study of the role of cardiovascular risk factors and fitness in industrial back pain complaints.

The authors conducted a prospective study of risk factors for industrial back pain complaints among 3,020 aircraft manufacturing employees. The study subjects completed a cardiovascular risk questionnaire, and were asked about their smoking status and past medical history, including previous back problems. Premorbid submaximal treadmill testing to predict maximum oxygen uptake (Vo2max) was completed in 2,434 subjects who were not excluded from testing due to cardiovascular risk screening. During several years of subsequent follow-up, 279 subjects reported back problems. Those who reported smoking at the time of the premorbid examination were significantly more likely to report a subsequent back problem than nonsmokers (P = 0.002). When controlling for sex and age, cardiovascular fitness, as measured through VO2max, was not predictive of future back injury reports (P = 0.26).

Isometric lifting strength as a predictor of industrial back pain reports.

The objective of our investigation was to study isometric lifting strength in a population of industrial workers who perform a great variety of manual tasks, and to determine whether isometric strength is predictive of future back problems in such a population. Of 3,020 study subjects, 2,178 (72%) underwent strength testing in three standard lifting positions. During a 4-year follow-up period, 172 subjects tested reported back problems. When examining each isometric lift separately as a predictor of industrial back pain reports, those with greater isometric strength were at significantly greater risk than were weaker workers. However, after controlling for the effects of age, only a slight trend remained. For the blue collar workers in this study, isometric lifting strength testing was ineffective in identifying individuals at risk for industrial back problems.

The role of spinal flexibility in back pain complaints within industry. A prospective study.

Commonly used clinical measurements of spinal flexibility in the sagittal and frontal planes were examined as predictors of future back pain reports within industry. The study sample consisted of 3,020 aircraft manufacturing employees who were examined and tracked for more than 4 years for reports of back pain. Modified Schober, sit-and-reach, and lateral bending measurements were not significantly associated with risk of future back pain reporting, nor were any trends present. There was a statistically significant relationship between decreased flexibility and reports of current or previous back problems. However, the differences in flexibility between subjects with and without a history of back problems were too small to be of practical significance.

Spinal flexibility and individual factors that influence it.

We conducted an investigation to examine the spinal flexibility of a large, adult population and to study the effects of other individual physical characteristics on spinal range of motion. The study group consisted of 3,020 blue collar employees (2,350 men and 670 women) who underwent a physical examination that included assessments of standing and sitting height, weight, shoulder flexibility, and spinal flexibility in the sagittal and frontal planes. Flexibility measures were correlated positively to one another; however, lumbosacral flexion measurements assessed by the modified Schober method correlated to the other flexibility measurements to a much lesser degree. Age, sex, and height affected ROM, as did obesity and the ratio of standing height to sitting height. The study findings indicate that spinal ROM covers a wide spectrum of values and is affected by many individual factors. Any attempts to determine what is normal, excessive, or diminished must take into account variations caused by age, sex, and other physical attributes.

The value of preemployment roentgenographs for predicting acute back injury claims and chronic back pain disability.

Preemployment roentgenographs have long been used in industry to screen job applicants. Roentgenographs have had little effect, however, in curbing the cost of back problems in industry. This study evaluates the capabilities of preemployment roentgenographs for predicting acute back injury claims within the longshoring industry and for predicting back problems that lead to back disability of more than six months. The data indicate that lumbosacral roentgenographs are not helpful in predicting who is more likely to make a back injury claim, or those few who make up the vast majority of the costs for industrial back pain by becoming disabled for more than six months. Lumbosacral roentgenographs have little link to back disorders and may be viewed as discriminatory. The radiation exposure is not justified by their predictive value as a preemployment screening tool.

Anthropometric and clinical measures as predictors of back pain complaints in industry: a prospective study.

A prospective, longitudinal investigation was conducted to investigate anthropometric and clinical examination measures as predictors of future back pain reports in industry. Associations between these measures and a history of back problems were examined as well. Participants in the study included 3,020 aircraft manufacturing employees who underwent an examination and then were tracked for greater than 4 years for subsequent back pain reports. Back symptoms elicited on straight leg raising (SLR) was the measure most significantly associated with subsequent back pain reporting among both men and women (p less than 0.0001). The only variables to add predictive value in addition to back pain on SLR were age and weight in women, and history of back problems and age in men.