Hip and knee pain: Role of occupational factors

Impact of Occupation on 12-Month Outcomes After Anterior Cruciate Ligament Reconstruction in Male Patients

Background

The impact of a physically demanding occupation on clinical outcomes after anterior cruciate ligament (ACL) reconstruction (ACLR) is largely unknown.

Purpose/Hypothesis

The purpose of this study was to assess the influence of occupation on 12-month outcomes after ACLR in male patients. It was hypothesized that patients undertaking manual work would not only have better functional outcomes in terms of strength and range of motion but also higher rates of joint effusion and greater anterior knee laxity.

Study Design

Cohort study; Level of evidence, 3.

Methods

From an initial cohort of 1829 patients, we identified 372 eligible patients aged 18 to 30 years who underwent primary ACLR between 2014 and 2017. Based on a preoperative self-assessment, 2 groups were established: patients engaged in heavy manual occupations and those engaged in low-impact occupations. Data were collected from a prospective database including effusion, knee range of motion (using side-to-side difference), anterior knee laxity, limb symmetry index for single hop and triple hop, International Knee Documentation Committee (IKDC) subjective score, and complications up to 12 months. Because of the significantly lower rate of female patients undertaking heavy manual occupations compared to low-impact occupations (12.5% and 40.0%, respectively), data analysis was focused on male patients. Outcome variables were assessed for normality, and statistical comparisons were made between the heavy manual and low-impact groups using either an independent-samples t test or the Mann-Whitney U test.

Results

Of 230 male patients, 98 were included in the heavy manual occupation group, and 132 were included in the low-impact occupation group. Patients in the heavy manual occupation group were significantly younger than those in the low-impact occupation group (mean age, 24.1 vs 25.9 years, respectively; P < .005). There was a greater range of active and passive knee flexion in the heavy manual occupation group than in the low-impact occupation group (mean active, 3.38° vs 5.33°, respectively [P = .021]; mean passive, 2.76° vs 5.00°, respectively [P = .005]). There was no difference in effusion, anterior knee laxity, limb symmetry index, IKDC score, return-to-sport rate, or graft rupture rate at 12 months.

Conclusion

At 12 months after primary ACLR, male patients engaged in heavy manual occupations had a greater range of knee flexion, with no difference in the effusion rate or anterior knee laxity, compared with those engaged in low-impact occupations.

How to Use Biomechanical Job Exposure Matrices with Job History to Access Work Exposure for Musculoskeletal Disorders? Application of Mathematical Modeling in Severe Knee Pain in the Constances Cohort

INTRODUCTION

Musculoskeletal disorders related to work might be caused by the cumulative effect of occupational exposures during working life. We aimed to develop a new model which allows to compare the accuracy of duration of work and intensity/frequency associations in application to severe knee pain.

METHODS

From the CONSTANCES cohort, 62,620 subjects who were working at inclusion and coded were included in the study. The biomechanical job exposure matrix "JEM Constances" was used to assess the intensity/frequency of heavy lifting and kneeling/squatting at work together with work history to characterize the association between occupational exposure and severe knee pain. An innovative model G was developed and evaluated, allowing to compare the accuracy of duration of work and intensity/frequency associations.

RESULTS

The mean age was 49 years at inception with 46 percent of women. The G model developed was slightly better than regular models. Among the men subgroup, odds ratios of the highest quartile for the duration and low intensity were not significant for both exposures, whereas intensity/duration were for every duration. Results in women were less interpretable.

CONCLUSIONS

Though higher duration increased strength of association with severe knee pain, intensity/frequency were important predictors among men. Exposure estimation along working history should have emphasis on such parameters, though other outcomes should be studied and have a focus on women.

Methodological Flaws in Meta-Analyses of Clinical Studies on the Management of Knee Osteoarthritis with Stem Cells: A Systematic Review

(1) Background: Conclusions of meta-analyses of clinical studies may substantially influence opinions of prospective patients and stakeholders in healthcare. Nineteen meta-analyses of clinical studies on the management of primary knee osteoarthritis (pkOA) with stem cells, published between January 2020 and July 2021, came to inconsistent conclusions regarding the efficacy of this treatment modality. It is possible that a separate meta-analysis based on an independent, systematic assessment of clinical studies on the management of pkOA with stem cells may reach a different conclusion. (2) Methods: PubMed, Web of Science, and the Cochrane Library were systematically searched for clinical studies and meta-analyses of clinical studies on the management of pkOA with stem cells. All clinical studies and meta-analyses identified were evaluated in detail, as were all sub-analyses included in the meta-analyses. (3) Results: The inconsistent conclusions regarding the efficacy of treating pkOA with stem cells in the 19 assessed meta-analyses were most probably based on substantial differences in literature search strategies among different authors, misconceptions about meta-analyses themselves, and misconceptions about the comparability of different types of stem cells with regard to their safety and regenerative potential. An independent, systematic review of the literature yielded a total of 183 studies, of which 33 were randomized clinical trials, including a total of 6860 patients with pkOA. However, it was not possible to perform a scientifically sound meta-analysis. (4) Conclusions: Clinicians should interpret the results of the 19 assessed meta-analyses of clinical studies on the management of pkOA with stem cells with caution and should be cautious of the conclusions drawn therein. Clinicians and researchers should strive to participate in FDA and/or EMA reviewed and approved clinical trials to provide clinically and statistically valid efficacy.

Effects of load mass and position on the dynamic loading of the knees, shoulders and lumbar spine during lifting: a musculoskeletal modelling approach

Musculoskeletal models may enhance our understanding of the dynamic loading of the joints during manual material handling. This study used state-of-the-art musculoskeletal models to determine the effects of load mass, asymmetry angle, horizontal location and deposit height on the dynamic loading of the knees, shoulders and lumbar spine during lifting. Recommended weight limits and lifting indices were also calculated using the NIOSH lifting equation. Based on 1832 lifts from 22 subjects, we found that load mass had the most substantial effect on L5-S1 compression. Increments in asymmetry led to large increases in mediolateral shear, while load mass and asymmetry had significant effects on anteroposterior shear. Increased deposit height led to higher shoulder forces, while the horizontal location mostly affected the forces in the knees and shoulders. These results generally support the findings of previous research, but notable differences in the trends and magnitudes of the estimated forces were observed.

Muscle strength gains after strengthening exercise explained by reductions in serum inflammation in women with knee osteoarthritis

Background Individuals with knee osteoarthritis have elevated circulating inflammatory markers and altered cartilage properties but it is unclear if these features adapt to exercise. We aimed to determine (1) whether inflammatory markers, cartilage transverse relaxation time and thickness mediate the effect of body mass index (BMI) on quadriceps strength at baseline; and (2) whether these changes explain variance in quadriceps strength improvements after 12 weeks of exercise in women with knee osteoarthritis. Methods This secondary analysis (17 women with clinical knee osteoarthritis) of a randomized control trial compared supervised group interventions, 3 times/week for 12 weeks (36 sessions): (a) weight-bearing progressive resistive quadriceps exercise or (b) attention control. (1) From baseline, separate linear regressions were conducted with strength (Nm/kg) as the dependent, BMI as the predictor, and c-reactive protein, tumor necrosis factor, interleukin-6, cartilage transverse relaxation time or thickness as potential mediators. (2) Multiple linear regression analyses were completed with 12-week strength change (post-pre) as the dependent, change in serum inflammatory markers and cartilage measurements as predictors, and age, BMI and adherence as covariates. Findings (1) At baseline, there was no mediation. (2) A decrease in each of interleukin-6 (β = -0.104 (95% confidence intervals: -0.172, -0.036), R² = 0.51, P < 0.007) and tumor necrosis factor (β = -0.024 (-0.038, -0.009), R² = 0.54, P < 0.005) was associated with strength gains. Interpretation At baseline, inflammatory markers and cartilage measurements do not act as mediators of BMI on quadriceps strength. After 12 weeks of exercise, reduced interleukin-6 and tumor necrosis factor were associated with increased quadriceps strength in women with knee osteoarthritis.

Manual material handling in the supermarket sector. Part 1: Joint angles and muscle activity of trapezius descendens and erector spinae longissimus

Work-related musculoskeletal disorders are highly prevalent in the supermarket sector with manual material handling being one of the most commonly identified occupational risk factors. This cross-sectional study applied inertial motion capture and electromyography (EMG) to measure full-body kinematics and muscle activity of trapezius descendens and erector spinae longissimus during 50 manual material handling tasks performed by 17 workers in two supermarkets. The handling of bread and cucumbers to high shelf heights showed the highest trapezius muscle activity (from 47% to 59% peak normalized EMG), while the handling of bananas as well as lifting milk, bread and cucumbers from low to high positions showed the highest erector spinae activity (from 59% to 71%). Twenty-two tasks involved flexing the shoulders and trunk more than 90° and 50°, respectively. Based on these results, several manual handling practices in supermarkets should be reconsidered to reduce the physical work demands.

Are functional variants of the microRNA-146a gene associated with primary knee OA? Evidence in Mexican mestizo population

MicroRNA-146a (miR-146a) is an inflammatory response regulator whose expression is deregulated in osteoarthritis (OA); variations in the miR-146a gene could affect OA risk. This study aimed to analyze the association between two functional variants of the miR-146a gene and primary knee OA in Mexican mestizo population. Methods and Results. A case-control study was conducted with cases defined as individuals aged ≥ 40 years with primary knee OA grade ≥ 2, according to the Kellgren-Lawrence system. Controls were volunteers with no primary knee OA with radiographic grade < 2. TaqMan allelic discrimination assays genotyped the rs2910164 and rs57095329. Allelic and genotypic frequencies, as well as the Hardy-Weinberg equilibrium (HWE), were calculated. The genetic association was tested under codominant, dominant, and recessive models. Non-conditional logistic regressions were carried out to estimate the association magnitude. We included 310 cases and 379 controls. Despite rs2910164 being in HWE, there was no association under codominant, dominant, and recessive models. In women with OA grade 2, the codominant model found a trend between the CC genotype and increased risk [OR (95% CI)  1.6 (0.7-3.5)]; the same trend was found in OA grade 4 in the codominant and recessive models [1.8 (0.6-5.4) and 2.0 (0.7-5.9)]. Conversely, in men with OA grade 4, the CC genotype tended to be associated with a lower risk in the codominant and recessive models [0.6 (0.1-6.0) and 0.5 (0.1-5.1)]. Conclusion. Our results show that miR-146a gene variants are not significantly associated with primary knee OA in Mexican mestizos.

A framework for studying risk factors for lower extremity musculoskeletal discomfort in nurses

Lower extremity musculoskeletal discomfort (MSD) is prevalent, but understudied, in nurses. A comprehensive, theoretical, aetiological model of lower extremity work-related MSD in hospital in-patient staff nurses was developed through a review of the literature to provide a framework for aetiological and intervention research. The framework informed the design of a survey of 502 hospital staff nurses. Symptom prevalence ranged from 32% in hip/thigh to 59% in ankle/foot regions. Logistic regression modelling using survey data showed that different work and personal factors were associated with discomfort in different regions of the lower extremity. Individual factors (e.g. older age, higher BMI or having any foot condition), physical factors (e.g. higher frequency of patient handling), psychosocial factors (e.g. lower job satisfaction) were associated with discomfort in one or more parts of the lower extremity. Future research should target these factors for intervention, to attempt to reduce occurrence of lower extremity discomfort in nurses. Practitioner Summary: Practitioners may find useful the illustrated, theoretical aetiological model of factors that could influence the prevalence of lower extremity discomfort in nurses. The model could guide conversations with nurses and observational analyses of nursing work. The model and survey results may provide ideas for intervention exploration. Abbreviations: MSD: musculoskeletal discomfort; BMI: body mass index; MSK: musculoskeletal; ICU: intensive care unit; NLERF: nurses' lower extremity MSD risk factor; NASA-TLX: NASA-task load index.

[Osteoarthrosis in the clinic of internal and occupational diseases: differential diagnostic aspects]

Osteoarthritis is a common pathology, which indicates the great medical and social significance of this disease. The article discusses the issues of pathogenesis, risk factors and diagnosis of professional and professionally caused osteoarthritis: the age of onset of the disease, the specifics of work, the localization of joint damage. Differential diagnosis issues are discussed.

Risk factors for development of lower limb osteoarthritis in physically demanding occupations: A narrative umbrella review

Objectives

Osteoarthritis (OA) is a common disorder which affects the joints. As relationships between occupational factors and lower limb OA have been widely studied in systematic reviews, the aim of this umbrella review was to synthesize their key findings in the risk factors for development of lower limb OA.

Methods

A systematic search was conducted using the databases PUBMED, Cumulative Index of Nursing and Allied Health Literature, and Elton B Stevens Company to identify reviews examining associations between lower limb OA and occupational tasks. These reviews were rated for their methodological quality before key data were extracted and synthesized.

Results

Sixteen reviews were found, seven pertained to the knee, four to the hip, two to a variety of joints, and three to both the hip and knee. One was deemed to be of high methodological quality, one of critically low methodological quality, and the others of moderate methodological quality. The reviews found moderate to good evidence for heavy occupational lifting to be associated with an increased risk of OA at the knee and the hip. Kneeling, squatting, and climbing, previous injuries to joints, being overweight and obese were also predictive of lower limb OA.

Conclusion

Occupations which involve heavy physical workloads increase the risk of developing lower limb OA. Heavy lifting, squatting, knee bending, kneeling, and climbing may all increase the risk of developing OA in both the knees and hips. Efforts to reduce exposure to these tasks, reducing joint injuries, optimizing bodyweight may reduce the risks of lower limb OA for occupations which are physically demanding.

DNA methyltransferase genes polymorphisms are associated with primary knee osteoarthritis: a matched case-control study

DNA methylation is an epigenetic mechanism involved in the development of primary osteoarthritis (OA). The association between DNA methyltransferases (DNMTs) genes polymorphisms and diseases in which DNA methylation plays a role in their pathogenesis has been described (e.g., cancer); however, its relationship with OA has not been investigated. The aim of this study was to analyze the association between DNMT1, DNMT3A, and DNMT3B polymorphisms with radiologic primary knee OA in Mexican mestizo population. A matched case-control study was conducted (ratio, 1:1). Cases included 244 subjects with definite radiographic knee OA (grade ≥ 2). Controls were matched by age and gender and were subjects with no definite radiographic knee OA/normal (grade < 2). The DNMTs polymorphisms were genotyped by TaqMan allelic discrimination assays. Conditional logistic regression was carried out, and the genetic association was tested under co-dominant, dominant, and recessive inheritance models. Haplotypes for DNMT1 polymorphisms were constructed and their associations were also tested. The CC genotypes of rs2228611 and rs2228612 of DNMT1 were associated with a lower risk for primary knee OA under a co-dominant and a recessive model [OR (95% CI) 0.4 (0.2-0.8)/0.5 (0.3-0.8) and 0.3 (0.1-0.8)/0.3 (0.1-0.7), respectively]. The CT haplotype of DNMT1 polymorphisms was associated with a lower risk [OR (95% CI) 0.71 (0.51-0.97)]. The CC genotype of rs2424913 of DNMT3B was associated with an increased risk under a co-dominant and a dominant model [OR (95% CI) 3.0 (1.1-8.0), and 1.6 (1.1-2.4), respectively]. Our results show that DNMTs polymorphisms are associated with primary knee OA.

Hip Osteoarthritis and Physical Workload: Influence of Study Quality on Risk Estimations-A Meta-Analysis of Epidemiological Findings

In this paper, we critically evaluate the quality of epidemiological evidence on hip osteoarthritis and workload published so far. The influence of study quality on risk estimations was analyzed in sensitivity meta-analyses and meta-regression analyses. Comprehensive searches for epidemiological studies of hip osteoarthritis and occupational workload were performed in literature databases and current reviews. All studies were assessed on the basis of study design, defined quality scores, and relevant confounders considered. In total, 34 suitable studies were identified for critical evaluation. Of these, 20 are prevalence studies and 14 incidence studies. Strong heterogeneity is observed in study design, quality level, and estimated exposure parameters. A consistent positive association between heavy physical workload and hip osteoarthritis was observed only among the male populations, not among the female populations. In general, cohort studies provided lower effect estimates than cross-sectional and population-based case-control studies. Studies with high quality scores also produced lower effect estimates than studies with low quality scores. Consideration of BMI as a confounder in published studies also yielded lower effect estimates than studies without consideration of BMI as a confounder. Our analyses indicate that high-quality studies of the association between occupational workload and hip osteoarthritis provide lower effect estimates than studies of lower quality.

Obesity, depression and hip pain

INTRODUCTION

Up to 64% of the general population reports experiencing chronic pain, with the hip being one of the most frequent sites. An association has been shown between chronic back pain, obesity and depression. To date, a similar association has not been investigated with chronic hip pain.

METHODS

A total of 2,515 subjects were chosen as a representative cross-section of the German population. Each was provided with a questionnaire that included the Regional Pain Scale, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), Beck Depression Inventory-Primary Care and Winkler social class index. Participant height and weight values were obtained from self-reports. Using logistic regression methodology, we analysed the association between hip pain, obesity and increased depression scores.

RESULTS

A total of 124 (4.9%) subjects reported chronic hip pain and an additional 39 (1.5%) reported chronic hip pain that was disabling. Hip pain affected 1-5 sites (oligolocular) in 47% of cases, and was widespread (6-19 sites) in 50%. Obesity and increased values on the depression scale were associated with an increased likelihood of chronic hip pain (odds ratio [OR] 2.55 and 8.53, respectively) compared with subjects without pain. Increased values on the depression scale (OR 28.22) increased the likelihood of experiencing disabling chronic hip pain in comparison with pain free individuals.

CONCLUSIONS

Hip pain is rarely the sole site of pain. Obesity and increased values on the depression scale are associated with chronic hip pain. Increased values on the depression scale are associated with disabling chronic hip pain.

Perceptions of working with chronic knee pain: A qualitative study

BACKGROUND

People with chronic knee pain may opt to continue to work without seeking specific ergonomic adaptations or disclose the existence or severity of their pain to work colleagues or supervisors due to the pressures of maintaining employment. To gain a deep personal perspective on how people with chronic knee pain cope while working [7, 8, 17, 18], qualitative research methods are a useful way of in encouraging meaningful discussion amongst workers with chronic knee pain of potential work-related strategies to minimize their work-related disability.

OBJECTIVE

To conduct an in-depth exploration of the impact of chronic knee pain on the working life of selected individuals. The specific aim was to identify barriers and enablers for promoting sustainable work within the work environment following the methodological principles from grounded theory.

METHOD

Eleven workers with chronic knee pain participated in one of three focus groups (age range 51-77 years). All focus group sessions were audiotaped and transcribed verbatim. Two researchers independently identified themes around the common challenges for continuing employment among older people with chronic knee pain.

RESULTS

The main themes expressed in these focus groups were: 1) the effect of knee pain on work productivity, 2) strategies to improve work productivity, and 3) future suggestions about sustainable work for older people with chronic knee pain. New insights gained from the focus groups included the extent of physical limitations due to chronic knee pain, lack of ergonomic policies within the workplace, types of work transitions utilized to accommodate knee pain, complexity of disclosure, social support at work, and the unpredictability of future arthritis progression.

CONCLUSION

This research suggests that in providing the appropriate work environment to enable individuals with knee pain to continue to be productive members of society, workplace strategies are needed to minimize the stigma and encourage communication about chronic knee pain, as well investment in appropriate ergonomic support equipment.

Knee pain in nursing home workers after implementation of a safe resident handling program

PURPOSE

Approximately 25-30% of nursing personnel experience knee pain (KP). We sought to identify physical and psychosocial work exposures, and personal factors related to prevalent, incident, and persistent KP 5-8 years after safe resident handing program (SRHP) implementation in nursing homes.

METHODS

Health and exposure information was obtained from worker surveys 5-6 years ("F5") and 7-8 years ("F6") post-SRHP implementation. Prevalent KP correlates were examined at F5; persistent and incident KP predictors were analyzed at F6, utilizing robust Poisson multivariable regression.

RESULTS

F5 KP prevalence (19.7%) was associated with combined physical exposures, and with either high job strain or low social support, in separate models. Two-year persistent KP was similarly associated with these psychosocial exposures. Being overweight was associated with KP in all analyses.

CONCLUSIONS

The SRHP program did not eliminate knee physical loading, which should be reduced to prevent nursing home worker KP. Workplace psychosocial exposures (high job strain, low social support) also appeared germane.

The Value of Phenotypes in Knee Osteoarthritis Research

Background:

Over the past decade, phenotypes have been used to help categorize knee osteoarthritis patients relative to being subject to disease, disease progression, and treatment response. A review of potential phenotype selection is now appropriate. The appeal of using phenotypes is that they most rely on simple physical examination, clinically routine imaging, and demographics. The purpose of this review is to describe the panoply of phenotypes that can be potentially used in osteoarthritis research.

Methods:

A search of PubMed was used singularly to review the literature on knee osteoarthritis phenotypes.

Results:

Four phenotype assembly groups were based on physical features and noninvasive imaging. Demographics included metabolic syndrome (dyslipidemia, hypertension, obesity, and diabetes). Mechanical characteristics included joint morphology, alignment, the effect of injury, and past and present history. Associated musculoskeletal disorder characteristics included multiple joint involvement, spine disorders, neuromuscular diseases, and osteoporosis. With the knee as an organ, tissue characteristics were used to focus on synovium, meniscus, articular cartilage, patella fat pad, bone sclerosis, bone cysts, and location of pain.

Discussion:

Many of these phenotype clusters require further validation studies. There is special emphasis on knee osteoarthritis phenotypes due to its predominance in osteoarthritic disorders and the variety of tissues in that joint. More research will be required to determine the most productive phenotypes for future studies.

Conclusion:

The selection and assignment of phenotypes will take on an increasing role in osteoarthritis research in the future.

Randomized Controlled Trial Investigating the Role of Exercise in the Workplace to Improve Work Ability, Performance, and Patient-Reported Symptoms Among Older Workers With Osteoarthritis

OBJECTIVE

The aim of this study was to evaluate the effectiveness of a 12-week workplace exercise program on work ability, performance, and patient-reported symptoms in older university employees with knee and/or hip osteoarthritis.

METHODS

Twenty-four participants with clinical hip and/or knee osteoarthritis were randomized to exercise or no exercise. At baseline and follow-up, several work (work ability, resilience), patient-reported (pain, physical function, depressive symptoms, self-efficacy), and performance outcomes (hip and knee strength, mobility performance) were measured.

RESULTS

Significant improvements in work ability (P < 0.049) and patient-reported outcomes (pain, function, depressive symptoms) existed in the exercise group. No improvements were demonstrated in the no exercise group.

CONCLUSIONS

Exercise in the workplace improved work ability and patient-reported symptoms in older workers with osteoarthritis. The benefits of workplace exercise programs should be studied in a larger sample in which attention is given to improving exercise adherence.

Identification of influential demographic and work-related risk factors associated to lower extremity pain perception among rice farmers

BACKGROUND

A high prevalence of musculoskeletal disorders and abnormal alignments of the lower extremities (LE) was found for rice farmers. It is important to investigate demographic and work-related risk factors associated with LE pain prior to developing intervention strategies addressing the problematic factors of the highest-risk task.

OBJECTIVE

To identify factors associated with LE pain in rice farmers for every stage of the cultivation process.

METHODS

Thirty experienced farmers (age of 45.9±6.21 (mean±SD)) rated LE pain experienced before and after each cultivation stage using the Standardized Nordic Questionnaire. Risk factors of pain were characterized based on expert risk assessment of tasks due to force, posture and motion, in addition to a conventional survey of demographic and other work-related information.

RESULTS

Ergonomic risk factors were found to be the strongest predictors of knee and foot pain perception, which induced a substantial increase of pain perception (up to 4.6 times) with varying extent for individual cultivation stages. The highest risk and pain perception was found during the planting performance. Age exhibited significantly positive association with foot pain during planting and harvesting. However, more experienced farmers perceived less foot pain, presumably by developing effective movement strategies.

CONCLUSIONS

The findings suggest that the planting process should be subject of further intervention development, especially for older farmers, with focus on reducing force, awkward posture and repetitive movement to minimize risk of LE pain.

Prevalence of Chronic Neck Pain, Low Back Pain, and Knee Pain and Their Related Factors in Community-Dwelling Adults in Iran: A Population-based National Study

BACKGROUND

Chronic musculoskeletal pain (CMP) is increasing in prevalence rapidly. Over the past 2 decades low back pain has been ranked globally as the primary cause of years lived with disability. The primary objective of this study was to investigate the prevalence of chronic neck pain (CNP), chronic low back pain (CLBP), and chronic knee pain (CKP) and their related risk factors in the national Iranian population.

METHODS

We analyzed data obtained through a cross-sectional, population-based survey of 7889 Iranians who were aged between 30 and 70 years.

RESULTS

The prevalence of CNP, CLBP, and CKP was 15.34%, 27.18%, and 29.97%, respectively. Female sex, aging, body mass index≥25, Lur or Arab ethnicity, illiteracy, passive smoking, positive osteoporosis history, and low or high physical activity levels were risk factors for CLBP, CNP, and CKP after adjustment for potential confounders. For example, in participants with a body mass index≥30, odds ratios for CNP, CLBP, and CKP adjusted for age, sex, ethnicity, living area, education, employment status, smoking, and physical activity levels were 1.26 (95% confidence interval [CI], 1.04-1.52), 1.37 (95% CI, 1.17-1.59), and 1.64 (95% CI, 1.41-1.91), respectively.

CONCLUSIONS

This is the first study investigating the prevalence of CNP, CLBP, and CKP in the national population of Iran. It shows some modifiable risk factors for CMP, and suggests that affordable planning for these risk factors can be valuable in preventing CMP globally. However, this is a cross-sectional study and future longitudinal studies in this field are necessary.

Relationship between physical activity and hip pain in persons with and without cam or pincer morphology: a population-based case-control study

OBJECTIVES

The purpose of the study was to determine if physical activity (PA) is a risk factor for persistent or recurrent hip pain in young and middle-aged persons with and without radiographic findings of cam or pincer morphology (CPM).

METHODS

A population sample of persons aged 20-49 with (cases) and without (controls) hip pain in Metro Vancouver, Canada, was selected through random digit dialing (RDD). Self-reported PA was expressed as average energy expenditure (MET-hours) per year, over lifetime. CPM was defined as alpha angle >55°, lateral centre edge angle (LCE) >40°, or positive cross-over sign.

RESULTS

Data were obtained for 500 subjects, 269 cases and 231 controls. Prevalence of radiographic CPM was 49% in the cases and 44% in the controls. In a logistic regression model adjusted for age, gender and CPM, total lifetime PA, including occupational, domestic and recreational activities, was significantly associated with hip pain (Odds ratio (OR) 1.30 per 1000 MET-hours, 95% CI 1.15-1.38). The effect of total PA was observed in those with CPM (1.44, 1.17-1.78) and without CPM (1.23, 1.04-1.45). For domestic activities, the association was seen only in those with CPM (significant interaction). When PA was categorized into quartiles, higher levels of PA were associated with a greater risk of pain.

CONCLUSIONS

PA, as measured by average energy expenditure over lifetime is a risk factor for hip pain in young and middle-aged persons. For some activities, the risk is likely increased in persons with radiographic evidence of CPM.

Personal and Workplace Environmental Factors Associated With Reduced Worker Productivity Among Older Workers With Chronic Knee Pain: A Cross-Sectional Survey

OBJECTIVES

The aim of this study was to explore personal and workplace environmental factors as predictors of reduced worker productivity among older workers with chronic knee pain.

METHODS

A questionnaire-based survey was conducted among 129 older workers who had participated in a randomized clinical trial evaluating dietary supplements. Multivariable analyses were used to explore predictors of reduced work productivity among older workers with chronic knee pain.

RESULTS

The likelihood of presenteeism was higher in those reporting knee pain (≥3/10) or problems with other joints, and lower in those reporting job insecurity. The likelihood of work transitions was higher in people reporting knee pain (≥3/10), a high comorbidity score or low coworker support, and lower in those having an occupation involving sitting more than 30% of the day.

CONCLUSION

Allowing access to sitting and promoting positive affiliations between coworkers are likely to provide an enabling workplace environment for older workers with chronic knee pain.

Acute joint pain in the emerging green collar workforce: Evidence from the linked National Health Interview Survey and Occupational Information Network (O*NET)

BACKGROUND

Green jobs are a rapidly emerging category of very heterogeneous occupations that typically involve engagement with new technologies and changing job demands predisposing them to physical stressors that may contribute to the development of joint pain.

METHODS

We estimated and compared the prevalence of self-reported acute (past 30 days) joint pain between green and non-green collar workers using pooled 2004-2012 National Health Interview Survey (NHIS) data linked to the Occupational Information Network Database (O*NET).

RESULTS

Green collar workers have a higher prevalence of acute joint pain as compared to non-green collar workers. Green collar workers with pain in the upper extremity joints were significantly greater than in the non-green collar workforce, for example, right shoulder [23.2% vs 21.1%], right elbow [13.7% vs 12.0%], left shoulder [20.1% vs 18.2%], and left elbow [12.0% vs 10.7%].

CONCLUSIONS

Acute joint pain reported by the emerging green collar workforce can assist in identifying at risk worker subgroups for musculoskeletal pain interventions.

Vitamin D and the characteristics associated with risk for knee pain among Korean older adults: Findings from a nationally representative survey

AIM

To explore vitamin D and the risk factors associated with knee pain in a representative population of Korean older adults METHODS: Data were analyzed from the Korean National Health and Nutrition Examination Survey (2010-2013). A total of 3874 participants (1728 men, 2146 women) aged 65 years and older who had a measured serum 25-hydroxyvitamin D level were evaluated. Multivariate logistic regression was used to investigate the relationship between serum vitamin D and knee pain severity RESULTS: Sex, age, obesity, education, knee radiographic osteoarthritis, hip pain and back pain were associated with having knee pain. Also, the level of serum 25-hydroxyvitamin D was not significantly associated with knee pain severity. After controlling for confounding factors, the level of serum 25-hydroxyvitamin D was not significantly associated with knee pain, and severity levels of mild, moderate and severe.

CONCLUSIONS

The results show that the serum vitamin D did not have a significant effect on knee pain in older adults in Korea. Geriatr Gerontol Int 2017; 17: 1278-1285.

Prevalence of musculoskeletal symptoms among agricultural workers in the United States: an analysis of the National Health Interview Survey, 2004-2008

Ergonomic risks from agricultural tasks can compromise musculoskeletal health of workers. This study estimated prevalence of musculoskeletal symptoms in a sample representing almost 2 million US agricultural industry workers. This study used National Health Interview Survey data from 2004 to 2008. Weighted prevalence was calculated by demographic and employment factors. Prevalence ratios were calculated using generalized linear models with the Poisson distribution assumption. Prevalence rates of low back and neck pain in the previous 3 months were 24.3% and 10.5%, respectively, among agricultural workers. Monthly prevalence of joint pain was 17.0% for hips/knees, 9.8% for shoulders, 9.5% for wrists/hands, 5.4% for elbows, and 4.7% for ankles/toes. Agricultural workers had a significantly higher prevalence of shoulder pain than all other industry workers (prevalence ratios [PR] = 1.28, 95% confidence interval [CI]: 1.02-1.61). This study provides detailed national estimates of musculoskeletal symptom prevalence to understand the burden and the need for intervention among agricultural workers.

Incidence of Chronic and Other Knee Pain in Relation to Occupational Risk Factors in a Large Working Population

OBJECTIVES

The aim of this study was to estimate the incidence of chronic and other knee pain (KP) in relation to occupational and personal risk factors among workers representative of a general working population.

METHODS

Of 3710 workers in a French region included in a surveillance network for musculoskeletal disorders (2002-2005), 2332 completed a follow-up questionnaire in 2007-2009 (Cosali cohort). The questionnaires included questions on musculoskeletal symptoms, and personal and occupational exposure. Incident cases of KP in 2007-2009 (i.e. with KP at follow-up but not at baseline) were dichotomized into chronic KP (>30 days in the previous year) and other KP. Associations between incident KP and personal and occupational factors at baseline were studied separately according to sex using multinomial logistic regression.

RESULTS

Of the 1616 respondents without KP at baseline, 122 (7.5%) reported chronic KP and 243 (15.0%) reported other KP. The incidence rate of chronic KP was estimated at 19.6 per 1000 worker-years (95% CI: 16.3-23.5). After adjustment for age and body mass index, significant associations were found between incident chronic KP and handling loads >4kg [odds ratio (OR) 2.1 (1.2-3.6) for men, OR 2.3 (1.1-5.0) for women] and kneeling >2h a day for men [OR 1.8 (1.0-3.0)].

CONCLUSIONS

This study highlights the high frequency of chronic KP in the working population and the role of occupational factors in its incidence, in particular those kneeling and handling loads.

The effect of sustained static kneeling on kinetic and kinematic knee joint gait parameters

Despite epidemiological evidence for kneeling as an occupational risk factor for knee osteoarthritis, biomechanical evidence is lacking. Gait knee joint mechanics, a common measure used to study knee osteoarthritis initiation, were used in the present study to investigate the effect of sustained static kneeling on the knee. Ten healthy male subjects (24.1 years ± 3.5) performed ten baseline walking trials, followed by a 30-min kneeling protocol and a second set of walking trials. Knee joint moments and angles were calculated during the stance phase. Within-subject root mean squared differences were compared within and between the pre- and post-kneeling gait trials. Differences were observed between the pre-kneeling and post-kneeling walking trails for flexion and adduction knee moments (0.12 Nm/kg ± 0.03, 0.07 Nm/kg ± 0.02) and angles (3.18° ± 1.22 and 1.64° ± 1.15), indicating that sustained static deep-knee flexion kneeling does acutely alter knee joint gait parameters.

Long-term persistence of knee pain and occupational exposure in two large prospective cohorts of workers

Background

The persistence of knee pain (KP) and its relationship with occupational factors were investigated in two prospective cohorts of French workers: retirees of the Gazel cohort and workers in the Cosali cohort.

Methods

KP was defined according to the Nordic questionnaire (>1 day in the last year), and the information was extracted from two questionnaires in 2006 and 2012 for the Gazel cohort, and in 2002–2005 and 2007–2010 for the Cosali cohort. The personal and occupational factors and the severity of KP were measured at baseline. Of the 4590 members of the Gazel cohort with KP at baseline, 4140(90.2%) were followed up, as were 637(63.1%) members of the Cosali cohort. Logistic models were used to evaluate associations (ORs) between occupational exposure and the persistence of KP separately by sex, adjusted on indicators of severity of KP.

Results

KP was no longer present at follow-up for 38.3% of Gazel men and 46.0% of Cosali men (33.4% of Gazel women and 50.6% of Cosali women). The persistence of KP in men was associated with carrying or handling heavy loads on univariate analyses and with kneeling on multivariate analyses, with ORs of 1.3(1.0-1.6) (Gazel) and 1.6(1.0-2.6) (Cosali). Climbing stairs was not significantly associated with the persistence of knee pain among men. The persistence of KP in women was not significantly associated with such occupational exposure.

Conclusions

This study highlights the role of occupational factors in the persistence of KP for men, in particular kneeling and handling/carrying loads.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-411) contains supplementary material, which is available to authorized users.

Determinants of MSK health and disability: lifestyle determinants of symptomatic osteoarthritis

It is frequently considered that, for many people, symptomatic osteoarthritis involving the lower limb joints is a largely preventable 'lifestyle disease'. The purpose of this review is to evaluate the most recent scientific evidence examining the effect of various lifestyle factors, such as physical activity, obesity, diet, smoking, alcohol and injury, on the development of symptomatic knee or hip osteoarthritis. The strengths and weaknesses of various studies are discussed, the magnitude of any demonstrated risks presented and current overall conclusions drawn.

Exercise for osteoarthritis of the hip

BACKGROUND

Current international treatment guidelines recommending therapeutic exercise for people with symptomatic hip osteoarthritis (OA) report are based on limited evidence.

OBJECTIVES

To determine whether land-based therapeutic exercise is beneficial for people with hip OA in terms of reduced joint pain and improved physical function and quality of life.

SEARCH METHODS

We searched five databases from inception up to February 2013.

SELECTION CRITERIA

All randomised controlled trials (RCTs) recruiting people with hip OA and comparing some form of land-based therapeutic exercise (as opposed to exercises conducted in water) with a non-exercise group.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected studies for inclusion. We resolved disagreements through consensus. Two review authors independently extracted data, assessed risk of bias and the quality of the body of evidence for each outcome using the GRADE approach. We conducted analyses on continuous outcomes (pain, physical function and quality of life) and dichotomous outcomes (proportion of study withdrawals).

MAIN RESULTS

We considered that seven of the 10 included RCTs had a low risk of bias. However, the results may be vulnerable to performance and detection bias as none of the RCTs were able to blind participants to treatment allocation and, while most RCTs reported blinded outcome assessment, pain, physical function and quality of life were participant self reported. One of the 10 RCTs was only reported as a conference abstract and did not provide sufficient data for the evaluation of bias risk.High-quality evidence from nine trials (549 participants) indicated that exercise reduced pain (standardised mean difference (SMD) -0.38, 95% confidence interval (CI) -0.55 to -0.20) and improved physical function (SMD -0.38, 95% CI -0.54 to -0.05) immediately after treatment. Pain and physical function were estimated to be 29 points on a 0- to 100-point scale (0 was no pain or loss of physical function) in the control group; exercise reduced pain by an equivalent of 8 points (95% CI 4 to 11 points; number needed to treat for an additional beneficial outcome (NNTB) 6) and improved physical function by an equivalent of 7 points (95% CI 1 to 12 points; NNTB 6). Only three small studies (183 participants) evaluated quality of life, with overall low quality evidence, with no benefit of exercise demonstrated (SMD -0.07, 95% CI -0.23 to 0.36). Quality of life was estimated to be 50 points on a norm-based mean (standard deviation (SD)) score of 50 (10) in the general population in the control group; exercise improved quality of life by 0 points. Moderate-quality evidence from seven trials (715 participants) indicated an increased likelihood of withdrawal from the exercise allocation (event rate 6%) compared with the control group (event rate 3%), but this difference was not significant (risk difference 1%; 95% CI -1% to 4%). Of the five studies reporting adverse events, each study reported only one or two events and all were related to increased pain attributed to the exercise programme.The reduction in pain was sustained at least three to six months after ceasing monitored treatment (five RCTs, 391 participants): pain (SMD -0.38, 95% CI -0.58 to -0.18). Pain was estimated to be 29 points on a 0- to 100-point scale (0 was no pain) in the control group, the improvement in pain translated to a sustained reduction in pain intensity of 8 points (95% CI 4 to 12 points) compared with the control group (0 to 100 scale). The improvement in physical function was also sustained (five RCTs, 367 participants): physical function (SMD -0.37, 95% CI -0.57 to -0.16). Physical function was estimated to be 24 points on a 0- to 100-point scale (0 was no loss of physical function) in the control group, the improvement translated to a mean of 7 points (95% CI 4 to 13) compared with the control group.Only five of the 10 RCTs exclusively recruited people with symptomatic hip OA (419 participants). There was no significant difference in pain or physical function outcomes compared with five studies recruiting participants with hip or knee OA (130 participants).

AUTHORS' CONCLUSIONS

Pooling the results of these 10 RCTs demonstrated that land-based therapeutic exercise programmes can reduce pain and improve physical function among people with symptomatic hip OA.

Occupational physical loading tasks and knee osteoarthritis: a review of the evidence

Purpose : To perform a systematic review with best evidence synthesis examining the literature on the relationship between occupational loading tasks and knee osteoarthritis (OA).

METHODS

Two databases were searched to identify articles published between 1946 and April, 2011. Eligible studies were those that (1) included adults reporting on their employment history; (2) measured individuals' exposure to work-related activities with heavy loading in the knee joint; and (3) identified presence of knee OA (determined by X-ray), cartilage defects associated with knee OA (identified by magnetic resonance imaging), or joint replacement surgery.

RESULTS

A total of 32 articles from 31 studies met the inclusion criteria. We found moderate evidence that combined heavy lifting and kneeling is a risk factor for knee OA, with odds ratios (OR) varying from 1.8 to 7.9, and limited evidence for heavy lifting (OR=1.4-7.3), kneeling (OR=1.5-6.9), stair climbing (OR=1.6-5.1), and occupational groups (OR=1.4-4.7) as risk factors. When examined by sex, moderate level evidence of knee OA was found in men; however, the evidence in women was limited.

CONCLUSIONS

Further high-quality prospective studies are warranted to provide further evidence on the role of occupational loading tasks in knee OA, particularly in women.

Baggage handler seniority and musculoskeletal symptoms: is heavy lifting in awkward positions associated with the risk of pain?

OBJECTIVES

Heavy lifting is associated with musculoskeletal disorders but it is unclear whether it is related to acute reversible effects or to chronic effects from cumulated exposure. The aim of this study was to examine whether musculoskeletal symptoms in Danish airport baggage handlers were associated with their seniority as baggage handler, indicating chronic effects from cumulated workload.

METHODS

We established a group of baggage handlers employed at Copenhagen Airport during the period 1983-2012 (n=3092) and a reference group of men in other unskilled occupations with less heavy work (n=2478). Data regarding work history, lifestyle and musculoskeletal symptoms were collected using a self-administered questionnaire (response rate 70.1% among baggage handlers and 68.8% among the reference group).

RESULTS

The ORs of self-reported musculoskeletal symptoms during the last 12 months in the neck/upper back, lower back, shoulders, elbows, wrists, hips and knees were significantly higher in baggage handlers than in the reference group. These differences were explained by significant linear effects of baggage handler seniority for six anatomical regions. Adjustment for age, body mass index, smoking and leisure-time physical activity did not change these results. The findings were stable over age strata and among present and former baggage handlers.

CONCLUSIONS

The risk of musculoskeletal symptoms in six anatomical regions increased with increasing seniority as a baggage handler. This is consistent with the assumption that cumulated heavy lifting may cause chronic or long-lasting musculoskeletal symptoms. However, we cannot exclude that other factors related to baggage handler seniority may explain some of the associations.

Work-related knee injuries treated in US emergency departments

OBJECTIVE

To characterize work-related knee injuries treated in US emergency departments (EDs).

METHODS

We characterized work-related knee injuries treated in EDs in 2007 and examined trends from 1998 to 2007 by using the National Electronic Injury Surveillance System-occupational supplement.

RESULTS

In 2007, 184,300 (± 54,000; 95% confidence interval) occupational knee injuries were treated in US EDs, accounting for 5% of the 3.4 (± 0.9) million ED-treated occupational injuries. The ED-treated knee injury rate was 13 (± 4) injuries per 10,000 full-time equivalent workers. Younger workers and older female workers had high rates. Strains/sprains and contusions/abrasions were common-frequently resulting from falls and bodily reaction/overexertion events. Knee injury rates declined from 1998 through 2007.

CONCLUSIONS

Knee injury prevention should emphasize reducing falls and bodily reaction/overexertion events, particularly among all youth and older women.

EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis

The objective was to develop evidence -based recommendations and a research and educational agenda for the non-pharmacological management of hip and knee osteoarthritis (OA). The multidisciplinary task force comprised 21 experts: nurses, occupational therapists, physiotherapists, rheumatologists, orthopaedic surgeons, general practitioner, psychologist, dietician, clinical epidemiologist and patient representatives. After a preliminary literature review, a first task force meeting and five Delphi rounds, provisional recommendations were formulated in order to perform a systematic review. A literature search of Medline and eight other databases was performed up to February 2012. Evidence was graded in categories I-IV and agreement with the recommendations was determined through scores from 0 (total disagreement) to 10 (total agreement). Eleven evidence-based recommendations for the non-pharmacological core management of hip and knee OA were developed, concerning the following nine topics: assessment, general approach, patient information and education, lifestyle changes, exercise, weight loss, assistive technology and adaptations, footwear and work. The average level of agreement ranged between 8.0 and 9.1. The proposed research agenda included an overall need for more research into non-pharmacological interventions for hip OA, moderators to optimise individualised treatment, healthy lifestyle with economic evaluation and long-term follow-up, and the prevention and reduction of work disability. Proposed educational activities included the required skills to teach, initiate and establish lifestyle changes. The 11 recommendations provide guidance on the delivery of non-pharmacological interventions to people with hip or knee OA. More research and educational activities are needed, particularly in the area of lifestyle changes.

Knee pain in patients with cancer after chemotherapy, radiotherapy, and bone marrow transplantation

The causes of knee pain in patients with cancer with are different from those without cancer, and the purpose of this study was to evaluate these differences. Thirty-six patients with cancer who had knee pain who had undergone 1 or more modalities of treatment, including chemotherapy, radiotherapy, and bone marrow transplant, for a primary diagnosis of cancer were compared with a cohort of 40 patients without cancer who had knee pain. All patients were evaluated clinically and underwent radiographic examination, and some underwent computed tomography or magnetic resonance imaging examination. Among patients with a primary diagnosis of cancer, the most common diagnosis was lymphoma (n=10), and the most common causes of knee pain were avascular necrosis of bone, osteoarthritis, insufficiency fractures, and septic arthritis. In 5 patients, the classical signs of a septic knee were not present. Other causes of knee pain included meniscus tear and anterior cruciate ligament rupture with instability. The most common diagnosis in patients without cancer was osteoarthritis of the knee. No patient without cancer was diagnosed with avascular necrosis, metastatic lesion, or insufficiency fracture. Two patients without cancer were diagnosed with septic arthritis of the knee. This study showed that the causes of knee pain in patients with cancer are different from those without cancer. Septic arthritis may present without the classical clinical signs in patients with cancer, and a high index of suspicion should be maintained for it.

Occupational activities and osteoarthritis of the knee

BACKGROUND

The prevalence of knee osteoarthritis (OA) is rising and the search for interventions to mitigate risk is intensifying. This review considers the contribution of occupational activities to disease occurrence and the lessons for prevention.

SOURCES

Systematic search in Embase and Medline covering the period 1996 to November 2011.

AREAS OF AGREEMENT

Reasonably good evidence exists that physical work activities (especially kneeling, squatting, lifting and climbing) can cause and/or aggravate knee OA. These exposures should be reduced where possible. Obese workers with such exposures are at additional risk of knee OA and should therefore particularly be encouraged to lose weight. AREAS OF UNCERTAINTY/RESEARCH NEED: Workplace interventions and policies to prevent knee OA have seldom been evaluated. Moreover, their implementation can be problematic. However, the need for research to optimize the design of work in relation to knee OA is pressing, given population trends towards extended working life.