Open Access
Open Peer Review

This article has Open Peer Review reports available.

How does Open Peer Review work?

Prevalence of low back pain by anatomic location and intensity in an occupational population

  • Matthew S Thiese1Email author,
  • Kurt T Hegmann1,
  • Eric M Wood1,
  • Arun Garg2,
  • J Steven Moore4,
  • Jay Kapellusch3,
  • James Foster2 and
  • Ulrike Ott1
BMC Musculoskeletal Disorders201415:283

DOI: 10.1186/1471-2474-15-283

Received: 11 April 2014

Accepted: 15 August 2014

Published: 21 August 2014



Low Back Pain (LBP) is a common and costly problem, with variation in prevalence. Epidemiological reports of rating of pain intensity and location within the low back area are rare. The objective is to describe LBP in a large, multi-center, occupational cohort detailing both point and 1-month period prevalence of LBP by location and intensity measures at baseline.


In this cross-sectional report from a prospective cohort study, 828 participants were workers enrolled from 30 facilities performing a variety of manual material handling tasks. All participants underwent a structured interview detailing pain rating and location. Symptoms in the lower extremities, demographic and other data were collected. Body mass indices were measured. Outcomes are pain rating (0–10) in five defined lumbar back areas (i) LBP in the past month and (ii) LBP on the day of enrollment. Pain ratings were reported on a 0–10 scale and subsequently collapsed with ratings of 1–3, 4–6 and 7–10 classified as low, medium and high respectively.


172 (20.8%) and 364 (44.0%) of the 828 participants reported pain on the day of enrollment or within the past month, respectively. The most common area of LBP was in the immediate paraspinal area with 130 (75.6%) participants with point prevalence LBP and 278 (77.4%) with 1-month period prevalence reported having LBP in the immediate paraspinal area. Among those 364 reporting 1-month period prevalence pain, ratings varied widely with 116 (31.9%) reporting ratings classified as low, 170 (46.7%) medium and 78 (21.4%) providing high pain ratings in any location. Among the 278 reporting 1-month period prevalence pain in the immediate paraspinal area, 89 (32.0%) reported ratings classified as low, 129 (46.4%), medium and 60 (21.6%) high pain ratings.


Pain ratings varied widely, however less variability was seen in pain location, with immediate paraspinal region being the most common. Variations may suggest different etiological factors related to LBP. Aggregation of different locations of pain or different intensities of pain into one binary classification of LBP may result in loss of information which may potentially be useful in prevention or treatment of LBP.


Low back pain Point prevalence 1-month period prevalence Intensity Location Epidemiological Cross-sectional analysis


Lifetime prevalence of low back pain (LBP) is reportedly 75-84% of the general population studied in developed countries, which includes working individuals, but also includes individuals who disabled and are not employed[16]. Direct costs for LBP are estimated between $20 billion and $98 billion in the US, with indirect annual costs included cost estimates are as high as $200 billion[7, 8]. The point prevalence of LBP among reported epidemiological studies of the general population in developed countries including Canada and the US ranges from 4.4% to 33.0% and 1-month period prevalence has ranged from 35% to 52.2%[2, 5, 815].

LBP prevalence is a common reported outcome, yet it is rarely well defined and reproducible[16, 816]. When epidemiological and clinical studies do define LBP, it has been generally defined as pain between the 12th rib and the gluteal fold[2, 5, 8, 9, 11]. We could not identify a single study that subdivided this area in order to more adequately describe LBP. Additionally, many studies assess pain rating, but simply aggregate all pain together[2, 5, 815]. While many randomized trials report mean pain ratings in the low back area, only two population based epidemiological articles described pain intensity in the low back area, but none could be identified that differentiated different regions of pain in the lumbar spine with stratified pain intensities[12, 17]. There is little reported regarding the pain rating or location distribution in a non-clinical population.

Limitations in LBP research include: i) subjective and inconsistent definitions of LBP regarding location and pain intensity[1822], ii) limited use of objective outcome measures as compared to the occurrence of purely subjective outcomes[1921, 23], iii) infrequent reporting of multiple LBP prevalence measures from the same population to allow for comparability[11, 20, 21, 23, 24], iv) lack of detailed LBP anatomical location descriptions[2022], and v) rarely reported pain ratings[20, 22, 24]. Conflicting results in the epidemiological literature have led to a recent consensus statement that recommended inclusion of intensity and duration measures in case definitions of LBP[22]. Still, there are no epidemiological reports detailing the anatomical location and pain intensities of low back pain in a large population. A review of 906 Randomized Controlled Trials for treatment of LBP identified that back pain is typically defined as any pain between the thorax and gluteal fold, encompassing a wide range, yet without definition to ascertain whether patterns of pain may denote different subgroups that are either more prone toward chronicity and/or responsive to different treatment options[25].

The objectives of this report are to describe by anatomic location the: (i) point and 1-month prevalence of LBP, and (ii) intensity of LBP in a large, multi-center, multi-plant occupational cohort. Additional analyses include assessment of lifetime prevalence of LBP, prevalence of symptoms into the lower extremities, and descriptions of lower extremity symptoms by location. This descriptive study is the first in a series of articles exploring these relationships in detail.


The Institutional Review Boards of the University of Utah, University of Wisconsin-Milwaukee and Texas A&M University approved this study. All participants provided written informed consent prior to enrolling in this study. This study conforms to the Strengthening and Reporting of Observational studies in Epidemiology (STROBE) recommendations. The study protocol has been described in detail elsewhere, thus a brief description of the methods is below[26]. The cohort data were collected from 2003–2012, with baseline data collected between 2003 and 2006.Participants were enrolled from 27 employers with 30 diverse facilities located in Illinois, Texas, Utah and Wisconsin, USA. Study participants employed at these facilities performed a variety of operations, including (a) poultry and meat processing; (b) baking; (c) printing; (d) order selection in grocery warehousing; (e) book packaging, clothing packaging, and palletizing in a distribution center; and (f) manufacturing of cabinets, glass windows and doors, electric lights, chemicals, garage doors, lawnmowers, airbags and automotive parts, small engines, metal parts, plastic parts, office chairs, ice cream, salt, and cosmetics. Production managers were enrolled if they were involved in manual material handing tasks that could be quantified. Workers with unpredictable job physical exposures if quantification of physical exposures would be difficult, including supervisors, fork lift operators, and clerical workers were not invited to participate.

Participating employers were approached because a majority of their employees performed manual material handling tasks, and thus the study population represents these workers, but is also similar in demographic measures to other working populations in developed countries, including another cohort by the same study group[2732]. Participants were invited based on estimates made by research team members of the Revised NIOSH Lifting Equation (NIOSH RLE) and were classified equally into low, medium and high rough exposure groups after performing preliminary analyses of a sample of jobs, blinded to health status of workers. The NIOSH RLE has been applied to estimate association between LBP and job physical factors. Participants were enrolled regardless of whether they did or did not have low back pain[33]. The cohort was created to evaluate relationships between a broad spectrum of job physical factors, including those used by the NIOSH RLE and the development of LBP. Eligible participants were: (i) at least 18 years of age, (ii) able to give informed consent, and (iii) without plans to retire or leave their employer within four years. Workers with probable frequent and unpredictable changes in job physical exposures were excluded. Multiple enrollments were performed at most plants to increase participation and reduce selection bias. Exact participation rates are not known, however estimated participation is greater than 75% at each individual plant, and as high as 96% at an individual plant. All workers at each plant who met the eligibility requirements were invited to participate, with an overall participation of >75% of all eligible workers. 897 were consented; however some (n = 69) did not have complete baseline data and were excluded from these analyses. All participants were employed and performing their normal job duties. Data collection occurred during normal work hours for these participants, and included baseline health and job measures beginning in 2003, monthly health assessments, and quarterly job assessments for changes. All enrollments and monthly follow ups were conducted at the participating company, however all data collected were kept strictly confidential. All efforts were taken to ensure privacy and confidentiality throughout the data collection process. All of the individuals involved in data collection, storage, analysis or dissemination of results were part of the research team and not employed by any of the companies involved in the study.

The Health Outcomes Assessment Team administered computerized questionnaires and computerized structured interviews after consent was obtained. These data instruments were developed for this study based on many reported associations or suspected risk factors relating to LBP[34]. These questionnaires and structured interview questions were constructed from prior epidemiological studies[3537]. All data collection instruments were extensively pre-pilot, pilot, and field tested to ensure accuracy and reproducibility prior to data collection. The questionnaire included medical health items and psychosocial factors including: (a) demographics, (b) past medical history, (c) psychosocial questions, and (d) other questions (e.g., sleeping patterns, smoking, and alcohol consumption). The questionnaire and structured interview questions are available in the study protocol paper[26]. Monthly assessments included focused questions about past pain, inquiries regarding new pain, and a focused physical exam if warranted. The monthly questions querying location and quality of LBP were the same as those for baseline.

The computerized structured interview was administered by trained Physical Therapists or Occupational Medicine Residents. Interviewers were standardized annually and followed the computerized questionnaire format, asking the same questions in the same order. LBP, pain ratings on a 0–10 scale, and pain anatomical location(s) were collected separately for each timeframe of: i) the day of enrollment, and ii) in the past month[26]. Tingling and/or numbness in the lower extremities in the past month were also collected; these two symptoms were not differentiated. Pain location was collected by the interviewer using a standardized body diagram (See Figure 1) and subsequent questions to determine the exact location and extent of the pain. A pain drawing was completed by the participant to assist in the identification of pain in the low back, specifically pain in multiple locations, however specific information regarding pain in each of the areas noted in Figure 1 were collected by the interviewer. Symptoms were recorded for all low back areas identified with having had pain any time in the past month. These divisions on the standardized body diagram were defined a priori by the research team. Height and weight were measured to calculate body mass indices (BMI).
Figure 1

Point prevalence and 1-month period prevalence of low back pain overlaid on the body diagram used with workers for anatomical localization of pain from a large (n = 828) multicenter occupational cohort in the US.

Case definitions

Case definitions for this report, each with 0–10 pain ratings, include: (i) LBP in the past month and (ii) LBP on the day of enrollment. Pain ratings of 1–3, 4–6, and 7–10 out of 10 were categorized into low, medium and high pain categories, respectively[38, 39]. Pain anatomical locations were categorized into one or more of 5 lumbar areas: (i) Left Lateral Lumbar area, (ii) Lumbar immediate paraspinal area, (iii) Right Lateral Lumbar area, (iv) Left Gluteal area, and (v) Right Gluteal area (Figure 1).

Statistical analysis

All analyses were conducted using SAS 9.2 (SAS Institute, Cary NC). Given the goal of this study is to report the prevalence of LBP, data are presented with descriptive statistics including mean ± standard deviation, frequency, percent, and 95% confidence interval around prevalence estimates.


There were 828 study subjects with complete baseline health data who were included in these analyses (see Table 1). Most of the subjects were male (n = 529, 63.9%), with a mean age of 38.8 ± 12.0 years and BMI of 29.3 ± 6.5 kg/m[2]. Slightly more than half were never smokers (n = 458, 55.3%) and 192 (23.2%) were past smokers. Few had diagnoses of diabetes mellitus (n = 37, 4.5%), high cholesterol (n = 155, 18.7%) or high blood pressure (n = 119, 14.4%). Few participants (n = 64, 7.7%) had ever been involved in a Workers’ Compensation claim for LBP. Some participants had seen a physician for their LBP (n = 198, 23.9%), had a narcotic prescription for LBP (n = 74, 8.9%) or been diagnosed with sciatica (n = 81, 9.8%). Participants had been working at their current job for a mean of 4.6 ± 5.9 years, and 31 had changed jobs in the past due to LBP.
Table 1

Baseline demographic and health status data from a large (n = 828) multicenter occupational cohort in the US


Total population

Continuous Data

Mean ± SD



Age (years)

38.8 ± 12.0


18.3 – 69.0

Body Mass Index (kg/m2)

29.3 ± 6.5


15.87 – 85.4

Systolic Blood Pressure (mm Hg)

128.8 ± 17.3


74 – 235

Diastolic Blood Pressure (mm Hg)

78.3 ± 10.9


43 – 147

Categorical Data


Frequency (%)



529 (63.9%)


299 (36.1%)

Lifetime Prevalence of LBP


526 (63.5%)

Diabetes Mellitus Diagnosis


37 (4.5%)

High Cholesterol Diagnosis (>200 mg/dl)


155 (18.7%)

High Blood Pressure Diagnosis


119 (14.4%)

Tobacco Use


458 (55.3%)


192 (23.2%)



178 (21.5%)

Point prevalence

Approximately one-fifth of the 828 (20.8%) participants reported LBP in any area on the day of enrollment, with the most common location of point prevalent LBP was immediate paraspinal, with 130 (75.6% of those with point prevalent pain) reporting pain in that area (see Figure 1). Of those with baseline or point prevalent pain, 58 (33.7%) reported pain ratings classified as low, 75 (43.6%) medium, and a surprisingly high 39 (22.7%) high pain ratings in any low back area. Similar trends in pain ratings were reported in the immediate paraspinal area, although with lower prevalence. Lateral region LBP pain ratings were similar between the left and right sides. Point prevalent pain was similar, though less common than 1-month period prevalent pain (data not shown).

Among the 172 study participants who reported pain on the day of enrollment, most participants (n = 104, 60.5%) reported pain in only one of the five anatomical regions (See Table 2). However, 68 (39.5%) participants reporting LBP pain on the day of enrollment reported pain in more than 1 area.
Table 2

One-month period and point prevalence – total number of structured body regions reported with pain from a large (n = 828) multicenter occupational cohort in the US

Regions with pain

Point prevalence frequency, n (%)

Point prevalence cumulative frequency, n (%)

1-month period prevalence frequency, n (%)

1-month period prevalence cumulative frequency, n (%)

No Pain

656 (79.2%)

656 (79.2%)

464 (56.01%)

464 (56.0%)

1 Region

104 (12.6%)

760 (91.8%)

207 (25.0%)

671 (81.0%)

2 Regions

32 (4.0%)

792 (95.7%)

65 (7.9%)

736 (88.9%)

3 Regions

27 (3.3%)

819 (98.9%)

78 (9.4%)

814 (98.3%)

4 Regions

3 (0.4%)

822 (99.3%)

6 (0.7%)

820 (99.0%)

5 Regions

6 (0.7%)

828 (100%)

8 (1.0%)

828 (100%)

One-month period prevalence

Out of the 828 subjects, nearly half (n = 364, 44.0% of total participants) reported having LBP within the month prior to enrollment. Of those 364 participants, 278 (73.6% of those with 1-month period prevalent pain), reported having pain that was in the immediate paraspinal lumbar area (see Figure 1). Again, the right side had non-significantly higher 1-month prevalence (40.4% and 40.2% respectively).Among those 364 reporting one-month period prevalence LBP, 78 (21.4%) reported pain classified as high in any low back body area (See Figure 2). 60 (16.5%) reporting high pain ratings in the immediate paraspinal lumbar area, with about half as many having reported high pain ratings for each of the lateral lumbar areas. A surprisingly small proportion had pain in the gluteal areas (3-4%). 157 (43.1%) of those reporting 1-month period prevalence reported pain in more than one area.
Figure 2

One-month period prevalence for workers pain severity rating (n = 364) by body diagram region from a large (n = 828) multicenter occupational cohort in the US. Box size indicates numbers of individuals in the respective pain category (vertical axis) and body diagram region (horizontal axis).

1-month period prevalence pain location patterns were similar to those of point prevalence; however the pain ratings were consistently higher, regardless of the location or number of areas involved.

Lower extremity pain, tingling and numbness

Nearly 1/5th of participants reported having ever had LBP that traveled into their legs, however relatively few (n = 59) had those symptoms within the past month (see Table 3).
Table 3

Lifetime prevalence of low back pain traveling into the calf among those who have low back pain from a large (n = 828) multicenter occupational cohort in the US

Ever traveling into the calf

N = 162 (19.6% of 828)

Right Side

71 (43.8%)

Left Side

54 (33.3%)

Bilateral, at the same time

21 (13.0%)

Bilateral, but at different times

16 (9.9%)

A minority (2.3-2.5%) reported tingling and numbness in any of the lower extremity regions in the prior month (see Table 4). The thigh was the most common location (1.5-1.8%). The frequencies of 1-month period prevalence of tingling and numbness in the right and left lower extremities were comparable on both sides. Approximately 37.5% had tingling and numbness in only one region of one lower extremity with the remainder in more than one lower extremity and/or region (see Table 5).
Table 4

One-month period prevalence of tingling and numbness in the lower extremities from a large (n = 828) multicenter occupational cohort in the US



Lateral calf

Medial calf



Any region


796 (95.1%)

789 (95.3%)

804 (97.1%)

797 (96.3%)

801 (96.7%)

769 (95.1%)

Right Only

15 (1.8%)

15 (1.8%)

9 (1.1%)

12 (1.5%)

11 (1.3%)

24 (2.9%)

Left Only

12 (1.5%)

11 (1.3%)

6 (0.7%)

11 (1.3%)

10 (1.2%)

21 (2.5%)


5 (0.6%)

13 (1.6%)

9 (1.1%)

8 (1.0%)

6 (0.7%)

14 (2.3%)

Table 5

One-month period prevalence of tingling and numbness in the multiple regions (thigh, lateral calf, medial calf, foot/feet, toes) of the lower extremities from a large (n = 828) multicenter occupational cohort in the US

Number of regions with tingling/numbness

Right leg

Left leg

Both legs

No regions

804 (97.1%)

807 (97.5%)

809 (97.7%)

1 Region

10 (1.2%)

8 (1.0%)

6 (0.7%)

2 Regions

3 (0.4%)

6 (0.7%)

7 (0.9%)

3 Regions

3 (0.4%)

1 (0.1%)

3 (0.4%)

4 Regions

3 (0.4%)

3 (0.4%)

3 (0.4%)

5 Regions

5 (0.6%)

3 (0.4%)

0 (0.0%)


Low back pain is common in a large, working occupational cohort, with 20.8% having LBP on the day of enrollment and 44.0% having had pain in the prior month. A total of 63.5% reported having had LBP lasting at least one day in his or her lifetime. The majority of point prevalent and 1-month period prevalent pain was reported in the immediate paraspinal area. Similar amounts of pain were reported in the right and left sides, but few reported gluteal pain in contrast with clinical experiences. Pain ratings varied widely, with a considerable number of participants having high pain ratings despite being apparently functional at work. Tingling and numbness in the lower extremities were relatively rare. Anecdotally, these results suggest many workers “live with” LBP and continue working, perhaps until pain either worsens or is intolerable.

As the mean age of the population at enrollment was 38 years, it is likely a portion of workers reporting no LBP history had not lived long enough to develop LBP while others may have forgotten prior pain, thus similar to other studies the lifetime cumulative prevalence estimate may substantially understate the true lifetime risk[2, 5, 813]. While these prevalence measures are comparable with results from prior publications, to our knowledge, this is the first detailed reporting of pain ratings and anatomic locations[2, 5, 813].

Pain ratings in an at-work population were considerably higher than expected, with 116 providing one-month LBP ratings classified as low, 170 medium and 78 with high pain ratings. Pain ratings on the day of enrollment ranged widely with 58 rating low, and 75 providing LBP ratings of medium. Because all participants were working at the time of data collection, we were surprised that an extraordinary 39 of 828 (4.7% of total participants, 22.7% of those with point prevalent pain) were also reporting high pain ratings at that time. These high pain ratings are generally synonymous with “severe” pain and which many have considered incompatible with productive work. Of those working with high pain ratings, only one was on light duty, and none of them saw a healthcare provider before the next monthly follow up.

A total of 114 reported pain ratings on the day of enrollment classified as medium or high. Many randomized trials investigating opioid treatment for LBP have had minimum pain rating inclusion criteria[25]. Trials for treatment of acute or subacute LBP have utilized inclusion criteria of at least 4/10 or 5/10 pain ratings[4043]. Trials assessing chronic pain had similar requirements[4450]. Similar minimum pain requirements are used in trials investigating muscle relaxants for acute and sub-acute LBP treatment[51, 52]. In this study, 114 participants (18.8%) had point prevalence pain meeting the criterion of ≥4/10 for opioid treatment on the day of enrollment and 248 (30.0%) met that criterion over the month prior to enrollment. As these participants were functional at work, these results raise concerns regarding the use of pain ratings as either a sole or primary treatment criterion[5355].

For this study, pain ratings of 7 to 10 out of 10 were considered high, or “severe”. These findings raise concerns about the efforts to record pain ratings in all patients[12, 5659]. Instead, a focus on function has been increasingly advocated[25, 6062]. As these results are from a large working population yet with considerable pain ratings, these data appear to provide indirect support for efforts to assess pain via a function-based approach.

There are few studies which have reported on the geographic distribution of LBP, with most reporting pain between the ribs and buttocks. This study found a high proportion of patients (278 of 828, 33.6%) with paraspinal pain in the past month. However, in a clinical setting patients frequently present with gluteal pain[63, 64]. Thus, the small proportions with point or 1-month period prevalence of gluteal pain were unexpected. Additionally, some believe that radiating pain, including into the gluteal areas signifies mild radiculopathy, however, the frequencies of sciatica in this study add to other evidence that suggest gluteal pain may be merely referred pain[25]. The utilization of a standardized, a priori back diagram instead of relying only on a pain picture may partially explain the lower prevalence of gluteal pain.

Additionally, there were a surprising number of participants who report pain in more than one low back area. 68/172 (39.5%) reported point prevalence pain in more than one low back area, as did 157/364 (43.1%) of those reporting 1-month period prevalence. Clinical anecdotes, which are all that are available in the literature, describe most patients as having relatively focused LBP, with few reporting wide-spread, diffuse LBP. These a priori divisions of LBP are based upon clinical experience of the researchers, and were selected to evaluate suspected differentiations of pain location. While there are multiple reports on widespread musculoskeletal pain in different body areas, the differentiation between focal point LBP and more widespread LBP has never been reported in the literature. These widespread pain areas, with many participants reporting pain in 3, 4 and all 5 areas, contradicts the concept that LBP manifests with one specific point of pain, as may be seen clinically. It is unknown as to the relationships, if any, between specific location(s) of LBP and either causal or prognostic factors. Evaluation of the relative importance of LBP location and associated factors may be possible. Also, there may be multiple etiological factors related to pain in different or multiple back locations, and/or psychosocial factors and assessment of these potential relationships are areas of further research.

Not surprisingly there are fewer prior reports of point prevalence compared to one-month period prevalence pain. Point prevalence and the corresponding LBP ratings are generally lower. However, this study found similarities between point prevalence and one month period prevalence pain in the range of pain ratings and the distribution of anatomical locations. We had expected the distribution of pain ratings to shift towards higher pain ratings when workers were asked to recall one-month LBP period prevalence instead of LBP point prevalence. Instead, we were surprised to find relatively little change in the distribution.

Strengths of this study include the large sample size, numerous employment settings involvement of employers in four diverse US states, complete data capture utilizing trained healthcare providers, a computerized structured interview and use of a body diagram to collect detailed information including pain locations and pain ratings. While younger and healthier than the general population, this dataset is similar to other occupational cohorts in age and proportion of chronic diseases such as diabetes mellitus, thyroid disease, smoking, body mass index[2732, 6570]. While we are unable to directly test potential differences between responders and non-responders, the comparability of the dataset to national expectations suggests these results are likely generalizable to other employed populations especially of manual material handling workers.

Weaknesses include reliance on primarily manufacturing and warehousing employee groups that may limit generalizability. Also, as there are no objective measures of LBP, this study relies on self-reported pain ratings. This study is subject to recall biases. Although there were no known labor strife issues to provoke such issues. Some underestimation due to workers absent with LBP on the day of enrollment is possible, although we enrolled at sites on multiple dates and intentionally sought to enroll those not present at the prior enrollments, thus reducing this potential source of selection bias. Additionally, research suggests that recalled pain ratings are relatively stable over a week, and it may be reasonable to expect that recall of pain ratings are similarly stable at 1 month[71].


There are variations in the pain ratings of both point prevalence and 1-month period prevalence measures of LBP within this large population, with smaller variation in pain ratings within different locations. These variations have not been described in the literature. These analyses demonstrate that there is variation of location and intensity of pain, which have commonly been classified in epidemiological studies evaluating potential causal factors as one binary LBP case by researchers and clinicians, regardless of pain location or intensity between the 12th rib and the gluteal fold. By aggregating these different locations of pain or different intensities of pain into one binary classification of LBP, researchers and clinicians may be losing important information about individuals that may be useful in prevention or treatment of LBP. Further research is needed to identify associations between variations in both intensity and location and different etiological factors related to LBP. Additional analyses of LBP within this cohort, including intensity and specific location of incident LBP cases which demonstrate temporality, may yield further insight regarding relationships between pain location or intensity and other factors such as psychosocial problems, co-morbid chronic diseases, or job physical factors.



Low back pain.



This study has been funded, in part, by grants from the National Institute for Occupational Safety and Health (NIOSH/CDC), 1 U 01 OH008083-01 and NIOSH Education and Research Center training grant T42/CCT810426-10. The CDC/NIOSH is not involved in the study design, data analyses or interpretation of the data. The authors wish to acknowledge the contributions of numerous individuals, many of whom perform volunteer, or only partially compensated work on this project. Additional sources of funding include the Universities and other, non-commercial resources.

BackWorks Study Research Team

University of Wisconsin-Milwaukee

Job Exposure Assessment Team:

Jay Kapellusch, PhD;

Suzanne Milholland, MS OTR;

Jessica Gin, MS;

Karen Wahlgren, MS, OTR;

Abigail D’Souza, MS OTR;

Joan Korpi, BS, OTR; Melissa Lemke, MS;

Vivek Kishore, MS;

Priyank Gupta, MS;

Prithma Reddy Moslay, PhD;

Joel Kapellusch, MS;

Bridget Fletcher, MS;

Christopher Hoge, BA;

Mary Fitzpatrick, MS, OTR;

Sruthi Boda, MS;

Parag Bhoyar, MS;

Andrew Olson;

Health Outcomes Assessment Team:

David L. Drury, MD, MPH;

James C. Foster, MD, MPH;

Michael Borkowski, MD;

Dennis Phillips, MD;

Gwen Deckow-Schaefer, MS, OTR;

Gail Groth, MS, OTR, CHT;

Ann Tesmer, MS, OTR;

Christine Walczak, MPT;

Lianne Froemming, OTR;

Chris Jesko, OTR;

Suzanne Marchant, OTR, CHT;

Meenu Sager;

Margaret Schueller, PT;

Jennifer Seeger-Jaeschke, OTR;

University of Utah

Health Outcomes Assessment Team:

Kurt T. Hegmann, MD, MPH;

Eric Wood, MD, MPH;

Hannah Edwards, MD, MPH,

Jeremy Biggs, MD, MSPH;

Edward Holmes, MD, MPH;

Bonnie Held, OTR, CHT;

Ryan Derby, MD, MPH,

Riann Robbins, BS

Atim Effiong, BS

Kylee Fon Tokita

William Caughey

Tessa Langley

Jessica Simmons, MS,

Lisa Hollien, BS,

August Mayai, BS,

Deborah Passey BS,

Sandra Eaton, MPH,

Darren Don, MD, MPH

Patrick Luedtke, MD, MPH

Robert Pinter, MD, MPH

Phil Jiricko MD, MPH

Anne Donohue, MD, MPH

Ruth Jessica Hanford, MD, MPH

Nancy Williams, MD, MPH

Christopher Dea, MD, MPH

Spencer Checketts, MD, MPH

Kelli Graziano, MD

Eryn Stansfield, MD

Melissa Cheng, MD, MPH

Christina Vokt, MD, MPH,

Susanne Thobe, MD, MPH,

Steven Ross, MD, MPH,

Steve Angerbauer, MD, JD,

Anne Donahue, MD,

Bin Yang, MD, MPH,

Carla Olsen, MD, MPH,

Christine Tabatzky, MD, MPH,

David Hazra, MD, MPH,

Kathy Chang, MD, MPH,

Laura Rachel Kaufman, MD, MPH,

Job Exposure Assessment Team:

Donald Bloswick, PhD, P.E., C.P.E.;

Richard Sesek, PhD, CSP, MPH;

Andrew Merryweather, PhD, MS

William Mecham, MS, CPE, CSP

Juan Rodriguez, MS

Duane Ferkovitch

Eric Ellis, MS

Matthew Reading, MS

Jeremy Templeton

Byungju Yoo, MS

James Nolin

Rameshwer Karingala, ME

Ryan Wiskerchen

Robert Poulsen, MS, M-Phil

Tyson Skinner, MS

Ryan Choi, MS

Bryan Adams, MS

Bryan Howard, PhD

Sharon Davis, MS

Jennifer Tolbert, ME

Derrick Franklin, ME

Christopher Brammer

Mohan Kallakanti

Statistical Analysis Team:

Thomas Greene, PhD

Greg Stoddard, MS

Richard Holubkov, PhD;

Xiaoming Sheng, PhD;

Matthew S. Thiese, PhD, MSPH,

Steven J. Oostema, MS,

Ulrike Ott, MSPH,

Sivithee Srisukhumbowornchai, MS

Texas A&M University

Health Outcomes Assessment Team

J. Steven Moore, MD, MPH;

Gordon Vos, PhD

John-Paul Stephens, PhD

Authors’ Affiliations

Department of Family and Preventive Medicine, Rocky Mountain Center for Occupational & Environment Health, School of Medicine, University of Utah
Center for Ergonomics, University of Wisconsin-Milwaukee
Occupational Science & Technology Department, College of Health Sciences, University of Wisconsin – Milwaukee
School of Rural Public Health, Texas A&M, University Health Science Center, College Station


  1. Heliövaara M, Sievers K, Impivaara O, Maatela J, Knekt P, Makela M, Aromaa A: Descriptive epidemiology and public health aspects of low back pain. Ann Med. 1989, 21: 327-333.View ArticlePubMedGoogle Scholar
  2. Cassidy JD, Carroll LJ, Côté P: The Saskatchewan health and back pain survey: the prevalence of low back pain and related disability in Saskatchewan adults. Spine. 1998, 23: 1860-View ArticlePubMedGoogle Scholar
  3. Dagenais S, Caro J, Haldeman S: A systematic review of low back pain cost of illness studies in the United States and internationally. Spine J. 2008, 8: 8-View ArticlePubMedGoogle Scholar
  4. Goetzel RZ, Hawkins K, Ozminkowski RJ, Wang S: The health and productivity cost burden of the "top 10" physical and mental health conditions affecting six large US employers in 1999. J Occup Environ Med. 2003, 45: 5-14.View ArticlePubMedGoogle Scholar
  5. Pai S, Sundaram LJ: Low back pain: an economic assessment in the United States. Orthop Clin North Am. 2004, 35: 1-View ArticlePubMedGoogle Scholar
  6. Waddell G: Low back pain: a twentieth century health care enigma. Spine. 1996, 21: 2820-View ArticlePubMedGoogle Scholar
  7. Katz JN: Lumbar disc disorders and low-back pain: socioeconomic factors and consequences. J Bone Joint Surg. 2006, 88: 21-24.View ArticlePubMedGoogle Scholar
  8. Mehra M, Hill K, Nicholl D, Schadrack J: The burden of chronic low back pain with and without a neuropathic component: a healthcare resource use and cost analysis. J Med Econ. 2011, 15: 245-252.View ArticlePubMedGoogle Scholar
  9. Kent PM, Keating JL: The epidemiology of low back pain in primary care. Chiropr Osteopath. 2005, 13: 13-View ArticleGoogle Scholar
  10. Walker BF, Muller R, Grant WD: Low back pain in Australian adults. health provider utilization and care seeking. J Manipulative Physiol Ther. 2004, 27: 327-335.View ArticlePubMedGoogle Scholar
  11. Loney PL, Stratford PW: The prevalence of low back pain in adults: a methodological review of the literature. Phys Ther. 1999, 79: 384-396.PubMedGoogle Scholar
  12. Korovessis P, Repantis T, Zacharatos S, Baikousis A: Low back pain and sciatica prevalence and intensity reported in a mediterranean country: ordinal logistic regression analysis. Orthopedics. 2012, 35: e1775-e1784.View ArticlePubMedGoogle Scholar
  13. Papageorgiou AC, Croft PR, Ferry S, Jayson MI, Silman AJ: Estimating the prevalence of low back pain in the general population. Evidence from the South Manchester Back Pain Survey. Spine. 1995, 20: 1889-1894.View ArticlePubMedGoogle Scholar
  14. Walker BF: The prevalence of low back pain: a systematic review of the literature from 1966 to 1998. J Spinal Disord. 2000, 13: 205-217.View ArticlePubMedGoogle Scholar
  15. Leboeuf-Yde C, Lauritsen JM: The prevalence of low back pain in the literature. A structured review of 26 Nordic studies from 1954 to 1993. Spine. 1995, 20: 2112-2118.View ArticlePubMedGoogle Scholar
  16. Itz C, Geurts J, Kleef M, Nelemans P: Clinical course of non‒specific low back pain: A systematic review of prospective cohort studies set in primary care. Eur J Pain. 2013, 17: 5-15.View ArticlePubMedGoogle Scholar
  17. Vasseljen O, Woodhouse A, Bjorngaard JH, Leivseth L: Natural course of acute neck and low back pain in the general population: The HUNT study. Pain. 2013, 154: 1237-1244.View ArticlePubMedGoogle Scholar
  18. Childs JD, Piva SR, Fritz JM: Responsiveness of the numeric pain rating scale in patients with low back pain. Spine. 2005, 30: 1331-1334.View ArticlePubMedGoogle Scholar
  19. Spitzer WO, LeBlanc FE: Scientific approach to the assessment and management of activity-related spinal disorders: a monograph for clinicians: report of the Quebec Task Force on Spinal Disorders: Harper & Row. 1987Google Scholar
  20. Deyo RA, Battie M, Beurskens A, Bombardier C, Croft P, Koes B, Malmivaara A, Roland M, Von Korff M, Waddell G: Outcome measures for low back pain research: a proposal for standardized use. Spine. 1998, 23: 2003-2013.View ArticlePubMedGoogle Scholar
  21. De Vet HC, Heymans MW, Dunn KM, Pope D, van der Beek A, Macfarlane G, Bouter L, Croft P: Episodes of low back pain: a proposal for uniform definitions to be used in research. Spine. 2002, 27: 2409-2416.View ArticlePubMedGoogle Scholar
  22. Pincus T, Santos R, Breen A, Burton AK, Underwood M: A review and proposal for a core set of factors for prospective cohorts in low back pain: a consensus statement. Arthritis Care Res. 2008, 59: 14-24.View ArticleGoogle Scholar
  23. Krause N, Ragland DR: Occupational disability due to low back pain: a new interdisciplinary classification based on a phase model of disability. Spine. 1994, 19: 1011-View ArticlePubMedGoogle Scholar
  24. Thiese MS, Hegmann KT, Wood EM, Garg A, Moore JS, Kapellusch JM, Foster J, Greene T, Stoddard G, Biggs J: Low-back pain ratings for lifetime, 1-month period, and point prevalences in a large occupational population. Human Factors. 2014, 56 (1): 86-97.View ArticlePubMedGoogle Scholar
  25. Hegmann K: Occupational medicine practice guidelines. Evaluation and management of common health problems and functional recovery in workers. Edited by: Elk G. 2011, Village (IL): American College of Occupational and Environmental Medicine (ACOEM), 3Google Scholar
  26. Garg A, Hegmann KT, Moore JS, Kapellusch J, Thiese MS, Boda S, Bhoyr P, Bloswick D, Merryweather A, Sesek R, Deckow-Schaefer G, Foster J, Wood E, Sheng X, Holubkov R: Study protocol title: a prospective cohort study of low back pain. BMC Musculoskelet Disord. 2013, 14: 84-View ArticlePubMedPubMed CentralGoogle Scholar
  27. Clark BK, Healy GN, Winkler E, Gardiner PA, Sugiyama T, Dunstan DW, Matthews CE, Owen N: Relationship of television time with accelerometer-derived sedentary time: NHANES. Med Sci Sports Exerc. 2011, 43: 822-828.View ArticlePubMedGoogle Scholar
  28. Silverstein BA, Fan ZJ, Bonauto DK, Bao S, Smith CK, Howard N, Viikari-Juntura E: The natural course of carpal tunnel syndrome in a working population. 2010, Scandinavian journal of work, environment & health, 384-393.Google Scholar
  29. Hegmann KT, Thiese MS, Wood EM, Garg A, Kapellusch J, Foster J, Biggs J, Edwards H, Wertsch J, Kendall R: Impacts of Differences in Epidemiological Case Definitions on Prevalence for Upper-Extremity Musculoskeletal Disorders. Hum Factors. 2013, 56 (1): 191-200.View ArticleGoogle Scholar
  30. Theorell T, Hammarström A, Gustafsson PE, Hanson LM, Janlert U, Westerlund H: Job strain and depressive symptoms in men and women: a prospective study of the working population in Sweden. J Epidemiol Community Health. 2013, 68 (1): 78-82. jech-2012-202294View ArticlePubMedGoogle Scholar
  31. Poulsen OM, Persson R, Kristiansen J, Andersen LL, Villadsen E, Ørbæk P: Distribution of subjective health complaints, and their association with register based sickness absence in the Danish working population. Scand J Public Health. 2013, 41: 150-157.View ArticlePubMedGoogle Scholar
  32. Löve J, Hensing G, Holmgren K, Torén K: Explaining the social gradient in sickness absence: a study of a general working population in Sweden. BMC Public Health. 2013, 13: 545-View ArticlePubMedPubMed CentralGoogle Scholar
  33. Waters TR, Putz-Anderson V, Garg A, Fine LJ: Revised NIOSH equation for the design and evaluation of manual lifting tasks. Ergonomics. 1993, 36: 749-776.View ArticlePubMedGoogle Scholar
  34. Bernard B: Musculoskeletal disorders and workplace factors: A critical review of epidemiologic evidence for work related musculoskeletal disorders of the neck, upper extremity, and low back. 1997, 97-141. (2nd Ed) CDC/NIOSHGoogle Scholar
  35. Kuorinka I, Jonsson B, Kilbom A, Vinterberg H, Biering-Sorensen F, Andersson G, Jorgensen K: Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms. Appl Ergon. 1987, 18: 233-237.View ArticlePubMedGoogle Scholar
  36. Hagberg M: Exposure variables in ergonomic epidemiology. Am J Ind Med. 1992, 21: 91-100.View ArticlePubMedGoogle Scholar
  37. Levine DW, Simmons BP, Koris M, Daltroy LH, Hohl GG, Fossel AH, Katz JN: A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg-Am. 1993, 75: 1585-PubMedGoogle Scholar
  38. Zelman DC, Hoffman DL, Seifeldin R, Dukes EM: Development of a metric for a day of manageable pain control: derivation of pain severity cut-points for low back pain and osteoarthritis. Pain. 2003, 106: 35-42.View ArticlePubMedGoogle Scholar
  39. Palos GR, Mendoza TR, Mobley GM, Cantor SB, Cleeland CS: Asking the community about cutpoints used to describe mild, moderate, and severe pain. J Pain. 2006, 7: 49-56.View ArticlePubMedGoogle Scholar
  40. Li C, Ni J, Wang Z, Gasparic M, Terhaag B, Uberall MA: Analgesic efficacy and tolerability of flupirtine vs. tramadol in patients with subacute low back pain: a double-blind multicentre trial*. Curr Med Res Opin. 2008, 24: 3523-3530.View ArticlePubMedGoogle Scholar
  41. Pareek A, Chandurkar N, Chandanwale AS, Ambade R, Gupta A, Bartakke G: Aceclofenac-tizanidine in the treatment of acute low back pain: a double-blind, double-dummy, randomized, multicentric, comparative study against aceclofenac alone. Eur Spine J. 2009, 18: 1836-1842.View ArticlePubMedPubMed CentralGoogle Scholar
  42. Perrot S, Krause D, Crozes P, Naim C: Efficacy and tolerability of paracetamol/tramadol (325 mg/37.5 mg) combination treatment compared with tramadol (50 mg) monotherapy in patients with subacute low back pain: a multicenter, randomized, double-blind, parallel-group, 10-day treatment study. Clin Ther. 2006, 28: 1592-1606.View ArticlePubMedGoogle Scholar
  43. Innes GD, Croskerry P, Worthington J, Beveridge R, Jones D: Ketorolac versus acetaminophen-codeine in the emergency department treatment of acute low back pain. J Emerg Med. 1998, 16: 549-556.View ArticlePubMedGoogle Scholar
  44. Peniston JH, Gould E: Oxymorphone extended release for the treatment of chronic low back pain: a retrospective pooled analysis of enriched-enrollment clinical trial data stratified according to age, sex, and prior opioid use. Clin Ther. 2009, 31: 347-359.View ArticlePubMedGoogle Scholar
  45. Peniston JH, Xiang Q, Gould EM: Factors affecting acceptability of titrated oxymorphone extended release in chronic low back pain - an individual patient analysis. Curr Med Res Opin. 2010, 26: 1861-1871.View ArticlePubMedGoogle Scholar
  46. Jamison RN, Raymond SA, Slawsby EA, Nedeljkovic SS, Katz NP: Opioid therapy for chronic noncancer back pain. A randomized prospective study. Spine (Phila Pa 1976). 1998, 23: 2591-2600.View ArticleGoogle Scholar
  47. Wasan AD, Davar G, Jamison R: The association between negative affect and opioid analgesia in patients with discogenic low back pain. Pain. 2005, 117: 450-461.View ArticlePubMedGoogle Scholar
  48. Ruoff GE, Rosenthal N, Jordan D, Karim R, Kamin M: Tramadol/acetaminophen combination tablets for the treatment of chronic lower back pain: a multicenter, randomized, double-blind, placebo-controlled outpatient study. Clin Ther. 2003, 25: 1123-1141.View ArticlePubMedGoogle Scholar
  49. Portenoy RK, Messina J, Xie F, Peppin J: Fentanyl buccal tablet (FBT) for relief of breakthrough pain in opioid-treated patients with chronic low back pain: a randomized, placebo-controlled study. Curr Med Res Opin. 2007, 23: 223-233.View ArticlePubMedGoogle Scholar
  50. Khoromi S, Cui L, Nackers L, Max MB: Morphine, nortriptyline and their combination vs. placebo in patients with chronic lumbar root pain. Pain. 2007, 130: 66-75.View ArticlePubMedGoogle Scholar
  51. Tüzün F, Ünalan H, Öner N, Ozguzel H, Kirazli Y, Icagasioglu A, Kuran B, Suzun S, Basar G: Multicenter, randomized, double-blinded, placebo-controlled trial of thiocolchicoside in acute low back pain. Joint Bone Spine. 2003, 70: 356-361.View ArticlePubMedGoogle Scholar
  52. Salzmann E, Pforringer W, Paal G, Gierend M: Treatment of chronic low-back syndrome with tetrazepam in a placebo controlled double-blind trial. J Drug Dev. 1992, 4: 219-228.Google Scholar
  53. Deyo RA, Smith DH, Johnson ES, Donovan M, Tillotson CJ, Yang X, Petrik AF, Dobscha SK: Opioids for back pain patients: primary care prescribing patterns and use of services. J Am Board Fam Med. 2011, 24: 717-727.View ArticlePubMedGoogle Scholar
  54. Cheng M, Sauer B, Johnson E, Porucznik C, Hegmann K: Comparison of opioid‒related deaths by work‒related injury. Am J Ind Med. 2013, 56: 308-316.View ArticlePubMedGoogle Scholar
  55. Effiong A, Hegmann K, Thiese M, Wolfkiel C, Ording J, Harris J, Schwei K: P225 The development of evidence based guidelines for opioid pain treatment. BMJ Qual Saf. 2013, 22: A71-A.View ArticleGoogle Scholar
  56. Fink R: Pain assessment: the cornerstone to optimal pain management. Proc (Bayl Univ Med Cent). 2000, 13: 236-Google Scholar
  57. Dalton JA, McNaull F: A call for standardizing the clinical rating of pain intensity using a 0 to 10 rating scale. Cancer Nurs. 1998, 21: 46-49.View ArticlePubMedGoogle Scholar
  58. Jones KR, Vojir CP, Hutt E, Fink R: Determining mild, moderate, and severe pain equivalency across pain-intensity tools in nursing home residents. J Rehabil Res Dev. 2007, 44: 305-View ArticlePubMedGoogle Scholar
  59. Gordon DB, Rees SM, McCausland MP, Pellino TA, Sanford-Ring S, Smith-Helmenstine J, Danis D: Improving reassessment and documentation of pain management. Jt Comm J Qual Patient Saf. 2008, 34: 509-517.PubMedGoogle Scholar
  60. Hayden JA, Van Tulder MW, Tomlinson G: Systematic review: strategies for using exercise therapy to improve outcomes in chronic low back pain. Ann Intern Med. 2005, 142: 776-785.View ArticlePubMedGoogle Scholar
  61. Koes BW, Van Tulder M, Lin C-WC, Macedo LG, McAuley J, Maher C: An updated overview of clinical guidelines for the management of non-specific low back pain in primary care. Eur Spine J. 2010, 19: 2075-2094.View ArticlePubMedPubMed CentralGoogle Scholar
  62. Ostelo RW, Deyo RA, Stratford P, Waddell G, Croft P, Von Korff M, Bouter LM, de Vet HC: Interpreting change scores for pain and functional status in low back pain: towards international consensus regarding minimal important change. Spine. 2008, 33: 90-94.View ArticlePubMedGoogle Scholar
  63. Kean Chen C, Nizar AJ: Prevalence of piriformis syndrome in chronic low back pain patients. A clinical diagnosis with modified FAIR Test. Pain Pract. 2013, 13 (4): 276-281.View ArticlePubMedGoogle Scholar
  64. Hopayian K, Song F, Riera R, Sambandan S: The clinical features of the piriformis syndrome: a systematic review. Eur Spine J. 2010, 19: 2095-2109.View ArticlePubMedPubMed CentralGoogle Scholar
  65. Dale AM, Harris-Adamson C, Rempel D, Gerr F, Hegmann K, Silverstein B, Burt S, Garg A, Kapellusch J, Merlino L, Thiese MS, Eisen EA, Evanoff B: Prevalence and incidence of carpal tunnel syndrome in US working populations: pooled analysis of six prospective studies. Scand J Work Environ Health. 2013, 39 (5): 495-505.View ArticlePubMedPubMed CentralGoogle Scholar
  66. Garg A, Hegmann KT, Wertsch JJ, Kapellusch J, Thiese MS, Bloswick D, Merryweather A, Sesek R, Deckow-Schaefer G, Foster J, Wood E, Kendall R, Sheng X, Holubkov R: The WISTAH hand study: a prospective cohort study of distal upper extremity musculoskeletal disorders. BMC Musculoskelet Disord. 2012, 13: 90-View ArticlePubMedPubMed CentralGoogle Scholar
  67. Garg A, Kapellusch JM, Hegmann KT, Thiese MS, Merryweather AS, Wang Y, Mallow EJ: The strain index and TLV for HAL: risk of lateral epicondylitis in a prospective cohort. Am J Ind Med. 2014, 57: 286-302.View ArticlePubMedGoogle Scholar
  68. Garg A, Thiese M, Hegmann K: Carpal tunnel syndrome and associated personal factors in a cohort at baseline. Am J Epidemiol. 2007, 165: S134-Google Scholar
  69. Harris-Adamson C, Eisen EA, Dale AM, Evanoff B, Hegmann KT, Thiese MS, Kapellusch J, Garg A, Burt S, Bao S, Silverstein B, Gerr F, Merlino L, Rempel D: The Impact of Gender on Personal, Health and Workplace Psychosocial Risk Factors for Carpal Tunnel Syndrome A Pooled Study Cohort. Proc Hum Factors Ergon Soc Ann Meet. 2013, 57: 911-914.View ArticleGoogle Scholar
  70. Holtermann A, Hansen JV, Burr H, Søgaard K: Prognostic factors for long-term sickness absence among employees with neck-shoulder and low-back pain. Scand J Work Environ Health. 2010, 36: 34-41.View ArticlePubMedGoogle Scholar
  71. Bolton JE: Accuracy of recall of usual pain intensity in back pain patients. Pain. 1999, 83: 533-539.View ArticlePubMedGoogle Scholar
  72. Pre-publication history

    1. The pre-publication history for this paper can be accessed here:


© Thiese et al.; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.