Physical Characteristics of the Back Are Not Predictive of Low Back Pain
Physical Characteristics of the Back Are Not Predictive of Low Back Pain
Background: In the working population, back disorders are an important reason for sick leave and permanent work inability. In the context of fitting the job to the worker, one of the primary tasks of the occupational health physician is to evaluate the balance between work-related and individual variables. Since this evaluation of work capacity often consists of a physical examination of the back, the objective of this study was to investigate whether a physical examination of the low back, which is routinely performed in occupational medicine, predicts the development of low back pain (LBP).
Methods: This study is part of the Belgian Low Back Cohort (BelCoBack) Study, a prospective study to identify risk factors for the development of low back disorders in occupational settings. The study population for this paper were 692 young healthcare or distribution workers (mean age of 26 years) with no or limited back antecedents in the year before inclusion. At baseline, these workers underwent a standardised physical examination of the low back. One year later, they completed a questionnaire on the occurrence of LBP and some of its characteristics. To study the respective role of predictors at baseline on the occurrence of LBP, we opted for Cox regression with a constant risk period. Analyses were performed separately for workers without any back antecedents in the year before inclusion ('asymptomatic' workers) and for workers with limited back antecedents in the year before inclusion ('mildly symptomatic' workers).
Results: In the group of 'asymptomatic' workers, obese workers showed a more than twofold-increased risk on the development of LBP as compared to non-obese colleagues (RR 2.57, 95%CI: 1.09 - 6.09). In the group of 'mildly symptomatic' workers, the self-reports of pain before the examination turned out to be most predictive (RR 3.89, 95%CI: 1.20 - 12.64).
Conclusion: This study showed that, in a population of young workers wh no or limited antecedents of LBP at baseline, physical examinations, as routinely assessed in occupational medicine, are not useful to predict workers at risk for the development of back disorders one year later.
Low back pain (LBP) is a prevalent health problem that imposes an enormous burden on individuals and society. Work-related factors such as bending and twisting, whole-body vibration, manual materials handling and individual variables such as history of pain and age have been consistently associated with the occurrence of low back pain in diverse settings, including occupational ones. At the work place, prevention has therefore focused upon the elimination of risk factors associated with physical load. Another strategy is to identify those employees at risk for developing low back pain, and to adjust work-related capacity as a function of the individual work capacity. Such an analysis is accomplished through a physical examination by an occupational health physician.
The evaluation of work capacity by an occupational health physician often consists of a physical examination of the back. According to a biomechanical vision, low back pain is caused by musculoskeletal dysfunctions at the level of the motion segments. Musculoskeletal dysfunctions, for example, could be assessed by evaluating the following physical characteristics of the back: (1) the static aspects such as kyphosis, lordosis, iliac crest inequality and scoliosis, (2) the spinal flexibility, (3) muscle force, (4) pain by palpation, and (5) a neurological assessment of the lower extremities. Body constitution is also often considered. An increased body mass index has been suggested to be associated with LBP by 1) excessive wear and tear resulting from the increased mechanical demands and/or 2) by detrimental metabolic factors associated with obesity. More research about the validity of such a physical examination in predicting low back episodes in working populations is however warranted. First, there are only a few prospective studies that have investigated the predictive value of a physical examination in working populations, and the results of these studies are mixed. There is evidence that a limitation of the range during a straight-leg raising test is predictive of future low back pain. Also the experience of back pain during the physical examination is predictive of future pain. Second, most studies have investigated the validity in workers who already complain about LBP, making it difficult to infer whether the results of the physical examination are due to real physical abnormalities or due to pain increases during the examination. Such design leaves the question unanswered whether future low back pain may be predicted by the same physical characteristics. The objective of this study is then (1) to assess the value of individual physical characteristics in predicting future low back pain in a sample of young workers without any antecedents of back disorders, (2) to assess the value of individual physical characteristics in predicting future low back pain in a sample of young workers with limited antecedents of back disorders, and (3) to compare the results between these two groups.
Abstract and Background
Abstract
Background: In the working population, back disorders are an important reason for sick leave and permanent work inability. In the context of fitting the job to the worker, one of the primary tasks of the occupational health physician is to evaluate the balance between work-related and individual variables. Since this evaluation of work capacity often consists of a physical examination of the back, the objective of this study was to investigate whether a physical examination of the low back, which is routinely performed in occupational medicine, predicts the development of low back pain (LBP).
Methods: This study is part of the Belgian Low Back Cohort (BelCoBack) Study, a prospective study to identify risk factors for the development of low back disorders in occupational settings. The study population for this paper were 692 young healthcare or distribution workers (mean age of 26 years) with no or limited back antecedents in the year before inclusion. At baseline, these workers underwent a standardised physical examination of the low back. One year later, they completed a questionnaire on the occurrence of LBP and some of its characteristics. To study the respective role of predictors at baseline on the occurrence of LBP, we opted for Cox regression with a constant risk period. Analyses were performed separately for workers without any back antecedents in the year before inclusion ('asymptomatic' workers) and for workers with limited back antecedents in the year before inclusion ('mildly symptomatic' workers).
Results: In the group of 'asymptomatic' workers, obese workers showed a more than twofold-increased risk on the development of LBP as compared to non-obese colleagues (RR 2.57, 95%CI: 1.09 - 6.09). In the group of 'mildly symptomatic' workers, the self-reports of pain before the examination turned out to be most predictive (RR 3.89, 95%CI: 1.20 - 12.64).
Conclusion: This study showed that, in a population of young workers wh no or limited antecedents of LBP at baseline, physical examinations, as routinely assessed in occupational medicine, are not useful to predict workers at risk for the development of back disorders one year later.
Background
Low back pain (LBP) is a prevalent health problem that imposes an enormous burden on individuals and society. Work-related factors such as bending and twisting, whole-body vibration, manual materials handling and individual variables such as history of pain and age have been consistently associated with the occurrence of low back pain in diverse settings, including occupational ones. At the work place, prevention has therefore focused upon the elimination of risk factors associated with physical load. Another strategy is to identify those employees at risk for developing low back pain, and to adjust work-related capacity as a function of the individual work capacity. Such an analysis is accomplished through a physical examination by an occupational health physician.
The evaluation of work capacity by an occupational health physician often consists of a physical examination of the back. According to a biomechanical vision, low back pain is caused by musculoskeletal dysfunctions at the level of the motion segments. Musculoskeletal dysfunctions, for example, could be assessed by evaluating the following physical characteristics of the back: (1) the static aspects such as kyphosis, lordosis, iliac crest inequality and scoliosis, (2) the spinal flexibility, (3) muscle force, (4) pain by palpation, and (5) a neurological assessment of the lower extremities. Body constitution is also often considered. An increased body mass index has been suggested to be associated with LBP by 1) excessive wear and tear resulting from the increased mechanical demands and/or 2) by detrimental metabolic factors associated with obesity. More research about the validity of such a physical examination in predicting low back episodes in working populations is however warranted. First, there are only a few prospective studies that have investigated the predictive value of a physical examination in working populations, and the results of these studies are mixed. There is evidence that a limitation of the range during a straight-leg raising test is predictive of future low back pain. Also the experience of back pain during the physical examination is predictive of future pain. Second, most studies have investigated the validity in workers who already complain about LBP, making it difficult to infer whether the results of the physical examination are due to real physical abnormalities or due to pain increases during the examination. Such design leaves the question unanswered whether future low back pain may be predicted by the same physical characteristics. The objective of this study is then (1) to assess the value of individual physical characteristics in predicting future low back pain in a sample of young workers without any antecedents of back disorders, (2) to assess the value of individual physical characteristics in predicting future low back pain in a sample of young workers with limited antecedents of back disorders, and (3) to compare the results between these two groups.
