Acute Effects of In-Hospital Resistance Training on Clinical Outcomes in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Trial

OBJECTIVE

The aim of the study is to evaluate the acute responses, in the in-hospital setting, of intensive elastic resistance training on physical function, pain, psychosocial variables, and inflammatory markers in patients undergoing total knee arthroplasty.

DESIGN

In a randomized controlled trial, 40 patients with total knee arthroplasty (≥55 yrs) were assigned to either (1) the intervention group (elastic resistance strengthening) or (2) a control group (conventional protocol). Patients performed three sessions in the hospital at 24, 48, and 72 hrs after total knee arthroplasty. Outcome measures included: self-administered physical function, pain intensity, kinesiophobia, catastrophizing, self-efficacy, range of motion, perceived change, test timed up and go, knee joint effusion, isometric strength, pressure pain thresholds, and inflammatory markers (levels of procalcitonin and C-reactive protein).

RESULTS

The mixed analysis of variance model showed a significant group*time interaction in favor of the intervention group with a large effect size for kinesiophobia (ηp 2 = 0.308, P < 0.001), catastrophizing (ηp 2 = 0.242, P < 0.001), and passive range of motion flexion (ηp 2 = 0.167, P < 0.001) and a moderate effect size for physical function (ηp 2 = 0.103, P = 0.004), pain intensity (ηp 2 = 0.139, P < 0.001), timed up and go (ηp 2 = 0.132, P = 0.001), self-efficacy (ηp 2 = 0.074, P = 0.016), active range of motion flexion (ηp 2 = 0.121, P = 0.002), levels of procalcitonin (ηp 2 = 0.099, P = 0.005), and C-reactive protein (ηp 2 = 0.106, P = 0.004).

CONCLUSIONS

Three sessions of intensive elastic resistance training improve physical function, perceived pain, psychosocial variables, and inflammatory markers during the hospitalization period after total knee arthroplasty.

Systematic Review of Workplace Interventions to Support Young Workers' Safety, Work Environment and Health

PURPOSE

This systematic review investigates the effectiveness of workplace interventions to support young workers' work environment, safety and health.

METHODS

A systematic search was conducted in bibliographic databases including PubMed, Web of Science Core Collection and PsycInfo for English or Scandinavian articles published from 2007 to 2022. The PICO strategy guided the assessment of study relevance and the bibliographical search for randomized controlled trials (RCTs) and non-RCTs in which (1) participants were young workers (mean age: 15-29), (2) interventions were initiated and/or carried out at the workplace, (3) a comparison group was included, and (4) an outcome measure related to work environment, safety and health was reported. We categorized each included study using the intervention classification framework. The quality assessment and evidence synthesis adhered to the guidelines developed by the Institute for Work & Health (Toronto, Canada).

RESULTS

A total of 33 high and medium quality studies showed a moderate level of evidence for no benefit of 'Mental training' on stress. We found limited evidence of a positive effect of the following intervention types: 'Attitude and belief' on mental health problems, 'Behavior based' on anxiety, and 'Multifaceted' on hand eczema. We found limited evidence for no benefit of the following intervention types: 'Mental training' on mental health problems, and 'Physiological modifications' on musculoskeletal disorders. The remaining intervention types showed mixed or insufficient evidence.

CONCLUSIONS

Except for a moderate level of evidence for no benefit of 'Mental training' on stress, the evidence synthesis recommends, that there is not enough evidence from the scientific literature to guide current practices. The results emphasizes a strong need for high quality interventions specifically aiming at increasing or maintaining young workers' work environment, safety and health. Included studies focused mainly on individual measures, highlighting the need for studies investigating possible preventive measures at the group or organizational level.

Association Between Pain Coping and Symptoms of Anxiety and Depression, and Work Absenteeism in People With Upper Limb Musculoskeletal Disorders: A Systematic Review and Meta-analysis

OBJECTIVE

To determine the prospective association of pain coping strategies and symptoms of anxiety and depression with work absenteeism in people with upper limb musculoskeletal disorders.

DATA SOURCES

A systematic search of PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases was conducted from inception to September 23, 2022.

STUDY SELECTION

Prospective observational studies of adults with upper limb musculoskeletal disorders were included. Included studies had to provide data on the association of pain coping strategies (catastrophizing, kinesiophobia, self-efficacy or fear avoidance) or symptoms of anxiety and depression with work absenteeism.

DATA EXTRACTION

Study selection, data extraction, and assessment of methodological quality (Newcastle Ottawa Scale) were performed by 2 independent authors. Random-effects models were used for quantitative synthesis.

DATA SYNTHESIS

Eighteen studies (n=12,393 participants) were included. Most studies (77.8%) reported at least 1 significant association between 1 or more exposure factors (pain coping strategies or symptoms of anxiety and depression) and work absenteeism. Meta-analyses showed a statistically significant correlation between the exposure factors of catastrophizing (r=0.28, 95% confidence interval [CI]: 0.15 to 0.40; P<.0001) and symptoms of anxiety and depression (r=0.23, 95% CI: 0.10 to 0.34; P=.0003) with work absenteeism. The correlation between self-efficacy and work absenteeism was non-significant (r=0.24, 95% CI: -0.02 to 0.47; P=.0747).

CONCLUSIONS

Rehabilitation teams should consider assessing catastrophizing and symptoms of anxiety and depression to identify patients at risk for work absenteeism. Addressing these variables may also be considered in return-to-work programs for individuals with upper limb disorders.

The importance of a healthy lifestyle despite chronic pain: Prospective cohort with 11-year register follow-up

The purpose of the study was to investigate to which extent a healthy lifestyle in female healthcare workers with chronic pain contributes to reducing the risk of disability pension. We conducted a prospective cohort study with an 11-year registry follow-up. Overall, 2386 Danish female healthcare workers with chronic pain completed a questionnaire about work and lifestyle (leisure-time physical activity, smoking, and body mass index (BMI)). Data on disability benefit payments were obtained from the Danish Register for Evaluation of Marginalization. Two models (minimally and fully adjusted for different potential confounders) were tested using the Cox proportional hazards model. During the follow-up period, 17.9% of the healthcare workers obtained disability pension. Low levels of leisure time physical activity (reference: moderate level) increased the risk of disability pension in the minimally (Hazard Ratio: 1.38 (95% CI: 1.14-1.69)) and fully adjusted models (Hazard Ratio: 1.27 (95% CI: 1.04-1.56)). Being highly physically active, as opposed to being moderately active, did not confer additional protection. Additionally, a positive association was observed between smoking and disability pension in the minimally adjusted model (Hazard Ratio: 1.27 (95% CI: 1.05-1.54)). BMI was not an influential factor. In female healthcare workers with chronic pain, at least moderate levels of physical activity is a protective factor for disability pension. Effective promotion strategies should be designed for both workplace and non-workplace settings.

Enhanced muscle endurance through self-regulated dual-task exercises in elbow fracture rehabilitation: A cross-sectional study

OBJECTIVE

The main objective of this study was to investigate the effect of a self-regulated dual task on muscle endurance within a single rehabilitation session in patients recovering from an elbow fracture.

DESIGN

Cross-sectional study of individuals recovering from elbow fractures (N = 20). Muscle endurance was tested using elastic bands at Borg's CR10 intensity 3- during four conditions: single-task and dual-task for elbow flexion and extension.

RESULTS

The cognitive condition significantly influenced muscle endurance (p < 0.001), while the type of elbow exercise (flexion or extension) did not significantly alter the results (p = 0.592). The perceived difficulty of the tasks showed a significant interaction effect (p = 0.032). The dual-task condition showed an average increase of about 15 repetitions. A moderate negative correlation was found between the differences in repetitions and the perceived difficulty of the flexion exercise (r = 0.677, p = 0.001).

CONCLUSIONS

Dual-task with self-regulation enhances muscle endurance among patients recovering from an elbow fracture. However, the improvements appear to depend on the perceived difficulty of the cognitive task. Future randomized controlled trials are required to understand the therapeutic implications of dual-tasking.

Does the distribution of musculoskeletal pain shape the fate of long-term sick leave? A prospective cohort study with register follow-up

ABSTRACT

Although multisite pain can markedly reduce work ability, the relevance of the bodily pain distribution as a predictor of long-term sick leave is still unknown. This study aimed to investigate the association between musculoskeletal pain distributions and long-term sick leave in the general working population of Denmark and included 66,177 currently employed wage earners without long-term sick leave during the prior 52 weeks. Participants reported whether they had pain in the lower extremity (hips/knees), upper extremity (neck/shoulders), or the low back. The analysis controlled for age, sex, year of survey reply, educational level, occupational group, psychosocial work factors, body max index, smoking, leisure-time physical activity, and mental health confounders. The results demonstrated that the risk of long-term sick leave increased with the number of pain sites. Compared with no pain, localized pain in any body region increased the risk/hazard by 25% to 29% (HR [95% CI]: 1.29 [1.07-1.54] for pain only in the low back), whereas pain in 2 regions increased the risk by 39% to 44% (HR [95% CI]: 1.41 [1.18-1.69] for pain in the low back + hips/knees). Workers reporting pain in all 3 regions experienced a 72% increased risk (HR [95% CI]: 1.72 [1.55-1.91]). Thus, the number of pain regions seems to matter more than the exact pain location. The spatial extension of musculoskeletal pain in workers functions as a gradient system, where pain spread throughout the body is an independent indicator of the high risk of long-term sick leave.

Dose-response association between cardiovascular health and mortality in cancer survivors

BACKGROUND

There is little knowledge on the dose-response association between cardiovascular health (CVH) and risk of all-cause, cardiovascular disease (CVD) and cancer deaths among cancer survivors.

AIMS

We aimed to examine the dose-response association of CVH with all-cause, CVD, and cancer mortality.

METHODS

A total of 1701 US adult cancer survivors were followed-up during a median of 7.3 (IQR 4.0-10.2) years from 2007 to 2018 through the National Health and Nutrition Examination Survey (NHANES). We used the American Heart Association´s (AHA) Life´s Essential 8 (LE8) as a proxy for CVH.

RESULTS

Restricted cubic spline models indicated a close to inverse linear shape for the dose-response association between LE8 score and all-cause mortality with significant risk reductions within the range between 61.25 (Hazard ratio [HR]: 0.76, 95% CI, 0.59-0.98) and 100 points (HR: 0.28, 95%CI, 0.12-0.62), and a curvilinear shape for the dose-response association between LE8 score and CVD deaths with significant risk reductions within the range between 50.25 (HR: 0.72, 95% CI, 0.52-0.99) and 90.25 points (HR: 0.15, 95%CI, 0.02-0.98). No significant dose-response association was observed between LE8 and cancer deaths.

CONCLUSIONS

Our study showed a close to inverse relationship between higher LE8 and risk of death from all cause, an inverse curvilinear relationship between higher LE8 and the risk for CVD death, and a non-significant association between higher LE8 and the risk of cancer death among US adult cancer survivors, which may translate to a substantial number of annual averted deaths and thus important public health implications.

Mental health and vitality predict spinal pain in healthcare workers

BACKGROUND

Despite extensive investigation of ergonomic risk factors for spinal pain in healthcare workers, limited knowledge of psychological risk factors exists.

AIMS

To assess the prospective association of mental health and vitality with development of spinal pain in healthcare workers.

METHODS

A prospective cohort study was carried out involving 1950 healthcare workers from 19 hospitals in Denmark. Assessments were done at baseline and at 1-year follow-up. Mental health and vitality were measured using the Short Form-36 Health Survey, while spinal pain intensity was measured using a 0-10 scale in the low-back, upper-back and neck, respectively. Cumulative logistic regressions adjusted for several confounding factors were applied, reporting risk estimates as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Using good mental health as reference, moderate (but not poor) mental health at baseline was associated with increased pain intensity in the low-back (OR: 1.41 [95% CI: 1.21-1.77]), upper-back (OR: 1.63 [95% CI: 1.31-2.02]) and neck (OR: 1.31 [95% CI: 1.07-1.61]) at 1-year follow-up. Likewise, using high vitality as reference, both moderate and low vitality at baseline were associated with increased pain intensity in the low-back (OR: 1.54 [95% CI: 1.22-1.94] and OR: 2.34 [95% CI: 1.75-3.12], respectively), upper-back (OR: 1.72 [95% CI: 1.34-2.23] and OR: 2.46 [95% CI: 1.86-3.25], respectively) and neck (OR: 1.66 [95% CI: 1.34-2.06] and OR: 2.06 [95% CI: 1.61-2.63], respectively) at 1-year follow-up.

CONCLUSIONS

Compared to healthcare workers with good mental health and high vitality, those with moderate mental health and low/moderate vitality, respectively, were more likely to increase spinal pain intensity at 1-year follow-up. These components should also be considered in the prevention of spinal pain in healthcare workers.

Gender differences on effects of forearm rotation on compressive stiffness of flexor carpi ulnaris during submaximal handgrip contractions

Little is known about gender differences in stiffness of forearm muscles during voluntary actions. This study aimed to investigate the effect of forearm rotation on flexor carpi ulnaris (FCU) stiffness in men and women during submaximal handgrip contractions. During a single session, measurements were made on 20 young participants (9 females). Two positions of the forearm were compared in random order with the elbow flexed 90 degrees: (i) neutral position and (ii) maximal supination. In each position, participants performed two submaximal handgrip contractions at 25% and 50% of maximal voluntary contraction, while compressive stiffness was collected using a hand myometer (MyotonPRO). A mixed repeated measurement ANOVA was applied to assess the interaction between gender, forearm position, and contraction intensity. The FCU stiffness is affected by handgrip contraction intensity (p < 0.001), gender (p < 0.001), BMI (p = 0.009), and forearm rotation (p = 0.007). Only the gender factor was found to have significant interaction with forearm rotation (p = 0.037). Men's FCU was stiffer than women's in both positions and contraction intensities (p < 0.05). Only in men a significant increase in FCU stiffness was observed when comparing contraction intensities at both forearm positions (p < 0.05), as well as when the forearm was rotated from neutral to supine at both intensities (p < 0.05). In conclusion, FCU stiffness during handgrip contraction differed significantly between men and women. Women have fewer stiffness changes in FCU when performing different levels of handgrip contraction. We also observed that only men increased FCU stiffness by changing the forearm position from neutral to supine position for both handgrip intensities.

Can Vitality and Mental Health Influence Upper Extremity Pain? A Prospective Cohort Study of 1185 Female Hospital Nurses

Musculoskeletal disorders of the upper extremity are among the most common occupational problems affecting nurses. The aim of this study was to analyze the prospective association between vitality and mental health and increased upper extremity pain intensity in female hospital nurses during a 1-year follow-up. A prospective cohort of 1185 female nurses from 19 hospitals in Denmark was conducted using baseline and 12-month follow-up questionnaires to identify potential associations between levels of vitality and mental health (SF-36 subscales) with pain intensity (0-10 scale) in the shoulder, elbow and hand/wrist regions. Associations were modeled using cumulative logistic regression. The fully adjusted model included the variables of age, baseline pain, body mass index, smoking status, years of occupation, leisure time physical activity level, number of daily patient transfers/handlings, as well as recognition and influence at work. The mean age was 48.3 (SD: 10.4) years. In the fully adjusted model, significant associations between low vitality levels and the odds of shoulder pain (OR = 1.96; 95%CI: 1.43-2.68) and hand/wrist pain (OR = 2.32; 95%CI: 1.58-3.42) were observed. Likewise, moderate levels of mental health was associated with increased odds of shoulder pain at follow-up (OR = 1.50; 95%CI: 1.16-1.93). These results provide an important incentive for nursing managers to assess vitality and mental health among hospital nurses and to consider this factor in prevention strategies to ensure good worker health and, by extension, high-quality care.

Health Promotion and Chronic Disease Prevention at the Workplace

The concept of workplace safety and health has focused largely on preventing accidents and on minimizing hazardous exposures. However, because workers spend a substantial part of their waking hours at the workplace, the potential to influence the health of a large proportion of the world's population through the workplace is enormous. The opportunities to carry out health promotion and chronic disease prevention activities at the workplace are countless, including (a) health screening; (b) tobacco cessation activities; (c) the promotion of healthy food choices and weight loss; (d) active breaks with physical exercise in terms of microexercise, enhancement of infrastructure, and organization of work tasks to facilitate incidental physical activity; and (e) routine vaccinations. This review discusses the key factors necessary to implement health promotion and chronic disease prevention programs at the workplace and discusses the different foci and possibilities with respect to the differing nature of work for the blue- versus white-collar workforce. Expected final online publication date for the Annual Review of Public Health, Volume 45 is April 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Pain Control Beliefs Predict Premature Withdrawal From the Labor Market in Workers With Persistent Pain: Prospective Cohort Study With 11-Year Register Follow-up

While a range of work-related psychosocial factors has been associated with various pain disorders and early retirement, less is known about pain cognitions and their influence on premature exit from the labor market. Therefore, as a primary objective, this study investigates associations between pain control beliefs and risk of disability pension among Danish eldercare workers. In 2005, 2257 female eldercare workers with low-back and/or neck/shoulder pain>90 days within the previous 12 months, replied to a survey and were followed for 11 years in a national register of social transfer payments. Using Cox regression, we estimated the risk of disability pension during follow-up from experiencing different levels of "pain control" and "pain influence," controlling for pain intensity and other relevant confounders. In the fully adjusted model for pain control with "high" as reference, hazard ratios of 1.30 (95% CI 1.03-1.64) and 2.09 (95% CI 1.45-3.01) are observed for "moderate" and "low," respectively, while the metric of pain influence shows hazard ratios of 1.43 (95% CI 1.11-1.87) and 2.10 (1.53-2.89), respectively. Pain control beliefs are associated with disability pension among eldercare workers with persistent pain. These results highlight the importance of evaluating not only bodily manifestations of pain, but also individual pain-related cognitions that may influence the experience of pain. PERSPECTIVE: This article addresses the complex experience of pain within an organizational context. We introduce the metrics of "pain control" and "pain influence" among workers with persistent pain, showing that the psychometric properties of these measures are prospectively associated with premature exit from the labor market.

Is Handgrip Strength Associated With Parkinson's Disease? Longitudinal Study of 71 702 Older Adults

BACKGROUND

To date, no study has longitudinally assessed the dose-response association between handgrip strength and incidence of Parkinson's Disease (PD).

OBJECTIVES

to investigate the longitudinal association between handgrip strength and the development of PD within a representative European population of older adults.

METHODS

Individuals aged 50 years and older from 27 European countries and Israel participated. We retrieved data from the Survey of Health, Ageing and Retirement in Europe waves 1, 2, 4, 5, 6, 7, and 8. Handgrip strength was measured using a hand dynamometer and participants reported whether they had a medical PD diagnosis. Time-varying exposure and covariates were modeled using both Cox regression and restricted cubic splines.

RESULTS

A total of 71 702 participants (mean age 65.2 years) were followed over a median period of 5.0 years. Among them, 314 participants developed PD. In the fully adjusted model, we observed a higher risk (hazard ratio [HR]: 2.50; 95% CI:1.92-3.32) of PD for participants with lower handgrip strength (third 1) and a lower risk of PD for participants in the second third (HR: 1.41; 95% CI: 1.06-1.87). In dose-response analyses, men showed lower risk of PD from 27 kg (HR:0.94; 95% CI: 0.91-0.97) to 59 kg (HR:0.10; 95% CI: 0.04-0.22), whereas women showed significant reductions from 24 kg (HR:0.68; 95% CI: 0.46-0.99) to 38 kg (HR:0.44; 95% CI: 0.22-0.88).

CONCLUSIONS

Handgrip strength ought to be incorporated as one of the measures in the prognostic toolbox for the screening of older adults who are possibly at risk of developing PD.

Dose-Response Association Between Handgrip Strength and Hypertension: A Longitudinal Study of 76,503 European Older Adults

To examine the prospective dose-response association between handgrip strength and the incidence of hypertension in a representative sample of older European adults. We retrieved data from the Survey of Health, Ageing and Retirement in Europe (SHARE) waves 1, 2, 4, 5, 6, 7, and 8. Handgrip strength was measured and participants reported whether they had a medical diagnosis of hypertension. We assessed the longitudinal dose-response associations of handgrip strength with hypertension using restricted cubic splines. During the follow-up, 27,149 (35.5%) were diagnosed with incident hypertension. At the fully adjusted model, the minimum and optimal dose of handgrip strength for a significant reduction in the risk of hypertension was 28 Kg (HR: 0.92; 95% CI: 0.89-0.96) and 54 Kg (HR: 0.83; 95% CI: 0.78-0.89), respectively. There exists an association between increased handgrip strength and reduced risk of developing hypertension in older European adults.

Musculoskeletal pain intensity and risk of long-term sickness absence in the general working population: A prospective cohort study with register follow-up

Determining predictors of sickness absence could allow for better screening, guidance, and development of preventive efforts aimed at those in increased risk. This study aimed to determine the prospective association between musculoskeletal pain intensity and risk of incident register-based long-term sickness absence in the general working population, as well as to determine the population attributable fraction. Drawing on data from a nation-wide questionnaire survey, this prospective cohort study followed a representative sample of the Danish general working population without recent long-term sickness absence (≥6 consecutive weeks) (n = 69,273) for long-term sickness absence up to two years (mean follow-up: 93 weeks) in a national register. The predictor was musculoskeletal pain intensity in the neck/shoulder and low-back during the preceding three months rated on an 11-point numerical rating scale from 0 to 10. The weighted incidence of long-term sickness-absence was 8.9% during two-year follow-up (n = 6165). We observed a clear dose-response association between musculoskeletal pain intensity of the neck/shoulder or low-back and the risk of incident long-term sickness absence, with a lower threshold of increased risk of 4 and 3 (scale 0-10) for neck/shoulder (HR (95% CI): 1.25 (1.09-1.42)) and low-back pain (HR (95% CI): 1.13 (1.00-1.29)), respectively. Prevention of pain intensities at or above 4 out of 10 could potentially prevent 17% (population attributable fraction, PAF (95% CI): 16.8 (13.6-20.1)) of the total long-term sickness absence in the general working population. Large-scale interventions to prevent and manage musculoskeletal pain need to be documented and implemented.

Trends in adherence to the muscle-strengthening activity guidelines in the US over a 20-year span

PURPOSE

Purpose to evaluate the prevalence and temporal trends in adherence to muscle-strengthening activity (MSA) guidelines among the US population from 1997 to 2018 (pre-Covid 19).

METHODS

We used nationally representative data from the National Health Interview Survey of the US (NHIS; a cross-sectional household interview survey). We pooled data from 22 consecutive cycles (1997 to 2018) and estimated prevalence and trends of adherence to MSA guidelines among adults aged 18-24 years, 25-34 years, 35-44 years, 45-64 years, and ≥ 65 years.

RESULTS

A total of 651,682 participants (mean age 47.7 years [SD = 18.0], 55.8% women) were included. The overall prevalence of adherence to MSA guidelines significantly increased (p < .001) from 1997 to 2018 (19.8% to 27.2%, respectively). Adherence levels significantly increased (p < .001) for all age groups from 1997 to 2018. Compared with their white non-Hispanic counterparts, the odds ratio for Hispanic females was 0.5 (95% CI = 0.4-0.6).

CONCLUSIONS

It is over a 20-year span, adherence to MSA guidelines increased across all age groups, although the overall prevalence remained below 30%. Future intervention strategies to promote MSA are required with a particular focus on older adults, women, Hispanic women, current smokers, those with low educational levels, and those with functional limitations or chronic conditions.

Barriers and facilitators of physical activity in adults with severe haemophilia: A qualitative study

BACKGROUND

People with haemophilia (PWH) tend to be less physically active than the general population, but there is a lack of research on the specific barriers and facilitators affecting their participation in physical activities.

OBJECTIVES

This study aims to explore perceived barriers and facilitators to physical activity in severe PWH.

DESIGN

An explorative qualitative study based on focus groups.

METHODS

Four focus groups including 16 participants (severe haemophilia A patients) were conducted to examine the factors perceived as facilitators or barriers to haemophiliacs engaging in physical activity. One researcher conducted a thematic analysis of all data.

RESULTS

Three themes were identified: body function, personal factors, and environmental factors. Key facilitators identified were access to prophylaxis treatment to reduce the risk of bleeding(s), the enjoyability of physical activity, fitness and health motives, social interaction, support, and low cost. PWH faced additional barriers to being physically active including hurtful joints, mobility issues, haemophilic arthropathy, dislike or disinterest, lack of motivation, fear of injury, tiredness, lack of time, lack of guidance, negative social influence, restriction, and lack of coordination of prophylaxis treatment.

CONCLUSION

This exploratory study demonstrated that participation in physical activity in PWH is influenced not only by their own abilities and attitudes, but also by external variables, including family, friends, healthcare professionals, structures, and communities. The results of this study may be used to assist caregivers and health professionals, inform programs, interventions, and policies to promote physical activity and health in severe PWH.

Maximal and Explosive Muscle Strength During Hip Adduction Squeeze and Hip Abduction Press Test Using A Handheld Dynamometer: An Intra- and Inter-tester Reliability Study

Background

Hip adduction and abduction muscle function plays an important role for risk of groin pain in athletes. Maximal isometric strength can be obtained clinically using a handheld dynamometer. However, in very strong athletes this is challenging, as external fixation of the dynamometer is needed for reliable measures. An alternative to unilateral testing, is the long-lever hip adduction squeeze test and a novel bilateral hip abduction press test. While promising intra-tester reliability has been found for maximal strength during the long-lever hip adduction squeeze test, inter-tester reliability may be more challenging during both maximal and explosive strength measurements.

Hypothesis/purpose

The aim of the present study was to assess intra- and inter-tester reliability of maximal, and explosive strength during the long lever hip adduction squeeze test and the long lever hip abduction press test in healthy adults using a hand-held dynamometer.

Study design

Intra- and interrater reliability study.

Methods

Forty-nine healthy subjects were included for intra- (n=20) and inter-tester reliability (n=29). Subjects performed the hip adduction long lever squeeze test and the bilateral hip abduction press test in a randomized order. Maximal isometric strength and early (0-100 ms) and late (0-200 ms) phase rate of force development (explosive muscle strength) was obtained using a hand-held dynamometer. Relative reliability for all tests was assessed using ICC2,1 two-way mixed model with absolute agreement, thereby taking bias between testers into account.

Results

Maximal isometric strength showed good intra- and inter-tester reliability for adduction (ICC: 0.93-0.97) and abduction (ICC: 0.88-0.92). For 0-200 ms rate of force development, both the squeeze and press test showed good intra-tester reliability (ICC: 0.85-0.87), whereas inter-tester reliability was good for hip adduction squeeze (ICC: 0.75) and moderate for hip abduction press (ICC: 0.71). For 0-100 ms rate of force development, the hip abduction press test showed good intra-tester reliability (ICC: 0.78). Remaining tests for intra- and inter-tester reliability showed moderate reliability (ICC: 0.50-0.71).

Conclusion

Assessment of maximal isometric strength in hip adduction squeeze and abduction press test showed good intra- and inter-tester reliability, whereas only 0-200 ms rate of force development demonstrated good intra-tester reliability of both tests. Therefore, rate of force development should preferably be conducted by the same tester, while the long lever squeeze and press test can reliably be used within- and between testers to measure maximal isometric strength.

Level of Evidence

3©The Author(s).

Study design of National Surveillance of the Work Environment of Employees in Denmark (NASWEED): Prospective cohort with register follow-up

AIM

The aim is to report the design and baseline data of the 'National Surveillance of the Work Environment of Employees in Denmark' study (NASWEED).

METHODS

NASWEED consist of (a) bi-annual cross-sectional samples, based on probability samples of wage earners of the general working population in Denmark from 2021 onwards (surveillance), (b) a prospective cohort of all previous respondents every two years (epidemiology, questionnaire follow-up) and (c) longitudinal follow-up in Danish registers about work and health (epidemiology, register follow-up). Between February and May 2021, a stratified (38 occupational industries) probability sample of 63,391 Danish residents aged 15-69 years who were employed for at least 34 hours per month received an invitation to participate, of whom 30,099 (47.5%) completed the questionnaire, 897 (1.4%) partially completed the questionnaire and 32,395 (51.1%) did not respond. Baseline was completed in June 2021. NASWEED covers various topics about the work environment (psychosocial, ergonomic, chemical, biological, safety, accidents, working from home, etc), health behaviours and somatic and mental health-related conditions. Statistical analyses will mainly build on survey procedures with model-assisted weights to ensure that the sample will yield representative estimates of the general working population.

DISCUSSION

NASWEED will monitor the development of the work environment and health in Denmark until 2030. The survey data will be included in epidemiological studies with repeated measurement of the work environment, health variables and covariates, and follow-ups in national registers to investigate the prospective association in the years and decades to come between the work environment and workers' health and labour market participation.

Work-limiting musculoskeletal pain and its association with loss of paid employment among senior workers: prospective cohort study with register follow-up

BACKGROUND

A growing population of elderly necessitates a sharpened focus on sustainable employment through aging. Physically demanding work can be challenging, especially for senior workers. Establishing determinants of labor market participation could guide policy development and preventive efforts at the workplaces aiming at keeping senior workers longer in the labor market.

METHODS

We used data from SeniorWorkingLife, a comprehensive questionnaire survey among a representative sample of Danish +50-year workers, and investigated the prospective association between self-reported work limitations due to musculoskeletal pain ('work-limiting pain') in 2018 and register-based loss of paid employment before state pension age at 2-year follow-up among +50-year Danish workers with physically demanding work (n = 3050).

RESULTS

Results showed that work-limiting pain increased the risk of loss of paid employment before the state pension age in a progressive manner, i.e. the higher degree of work-limiting pain, the higher risk of loss of paid employment (P < 0.001). Experiencing a low degree of work-limiting pain was associated with an 18% increased risk of loss of paid employment [risk ratio (RR): 1.18, 95% confidence interval (CI): 1.14-1.21], whereas experiencing a very high degree of work-limiting pain increased the risk of loss of paid employment by 155% (RR: 2.55, 95% CI: 2.43-2.69) compared to no work-limiting pain.

CONCLUSION

In conclusion, work-limiting pain constitutes an important risk factor for loss of paid employment among senior workers with physically demanding work, and effective preventive efforts at both policy and workplace levels should be documented and implemented.

Analgesics and ASH medications in workers increase the risk of disability pension and mortality: prospective cohort

BACKGROUND

Relying on medication for musculoskeletal and mental disorders are common, but may have long-term consequences. This study investigates whether use of analgesics and anxiolytic/sedative/hypnotic (ASH) medication increases the risk of disability pension and mortality.

METHODS

After completing a survey in 2005, 7773 female eldercare workers were followed for 11 years in a national register. We estimated hazard ratios (HRs) for disability pension and mortality from using analgesics and ASH.

RESULTS

During follow-up, 10.3% obtained disability pension and 2.4% died. For use of analgesics, a frequency-response association for the risk of disability pension existed with HR's (95% confidence interval) of 1.30 (1.07-1.57), 2.00 (1.62-2.46) and 3.47 (2.69-4.47) for monthly, weekly and daily use, respectively. For ASH, an increased risk of disability pension also existed (HR's between 1.51 and 1.64). For mortality risk, only daily use of analgesics and ASH remained significant. Population attributable fractions of analgesics and ASH, respectively, were 30% and 3% for disability pension and 5% and 3% for mortality.

CONCLUSIONS

Frequent use of analgesics and ASH medication in workers increase the risk of disability pension and early death. Better management of musculoskeletal and mental health conditions, without excessive medication use, is necessary.

Duration and intensity of occupational lifting and risk of long-term sickness absence: Prospective cohort study with register follow-up among 45 000 workers

OBJECTIVE

This study aimed to investigate the prospective association of lifting duration and lifting load with the risk of long-term sickness absence (LTSA).

METHODS

We followed manual workers with occupational lifting (N=45 346) from the Work Environment and Health in Denmark Study (2012-2018) for two years in a high-quality national register on social transfer payments (DREAM). Cox regressions with model-assisted weights were employed to estimate the risk of LTSA from lifting duration and loads.

RESULTS

During follow-up, 9.6% of the workers had an episode of LTSA. Compared to workers with seldom lifting (reference), workers lifting ½ and ¾ of the workday had increased risk of LTSA [hazard ratios (HR) of 1.36 [95% confidence interval (CI) 1.20-1.56] and 1.22 (95% CI 1.07-1.39)], respectively. Lifting load showed a positive exposure-response association with LTSA (trend test, P<0.01), with HR for lifting 5-15, 16-29, and ≥30 kg at 1.11 (95% CI 1.02-1.22), 1.17 (95% CI 1.03-1.34), and 1.29 (95% CI 1.11-1.50), respectively. Age-stratified analyses showed increased risk of LTSA among workers ≥50 years with a high proportion of work-related lifting compared to their younger counterparts.

CONCLUSIONS

Occupational lifting for ½ the workday increased the risk of LTSA, while higher occupational lifting load exacerbated this risk in an exposure-response manner. The study underscores the importance of reducing both lifting duration and loads for prevention of LTSA at the workplace, especially among older workers.

Dose-response association of handgrip strength and risk of depression: a longitudinal study of 115 601 older adults from 24 countries

BACKGROUND

Prior research has solely focused on the association between handgrip strength and risk of depression in single countries or general populations, but more knowledge is required from wider-spread cohorts and target populations.

AIMS

This study aimed to investigate the association between handgrip strength and risk of depression using repeated measures in adults aged 50 years and over.

METHOD

Data on handgrip strength and risk of depression were retrieved from the Survey of Health, Ageing and Retirement in Europe (SHARE) waves 1, 2, 4, 5, 6 and 7, using a hand dynamometer (Smedley, S Dynamometer, TTM) and the EURO-D 12-item scale, respectively. Time-varying exposure and covariates were modelled using both Cox regression and restricted cubic splines.

RESULTS

A total of 115 601 participants (mean age 64.3 years (s.d. = 9.9), 54.3% women) were followed-up for a median of 7.3 years (interquartile range: 3.9-11.8) and 792 459 person-years. During this period, 30 208 (26.1%) participants experienced a risk of depression. When modelled as a continuous variable, we observed an inverse significant association for each kg increase of handgrip strength and depression up to 40 kg in men and up to 27 kg in women.

CONCLUSIONS

Being physically strong may serve as a preventive factor for depression in older adults, but this is limited up to a maximum specific threshold for men and women.

Exercise variables and pain threshold reporting for strength training protocols in people with haemophilia: A systematic review of clinical trials

INTRODUCTION

Although strength exercise is often prescribed for people with haemophilia (PWH), it remains unknown how exercise variables and pain thresholds are used to prescribe strength training in PWH.

AIM

To analyse how strength exercise variables and pain thresholds have been used to prescribe strength training in PWH.

METHODS

A systematic search was conducted in PubMed, Embase, Web of Science, CENTRAL and CINAHL databases from inception to 7 September 2022. Studies whose intervention included strengthening training in adults with haemophilia were included. Two independent reviewers were involved in study selection, data extraction and risk of bias assessment.

RESULTS

Eighteen studies were included. The least reported variables among the studies were: prophylactic factor coverage (11.1%), pain threshold/tolerability (5.6%), intensity (50%), total or partial range of motion (27.8%), time under tension (27.8%), attentional focus modality (0%), therapist experience in haemophilia (33.3%) and adherence assessment (50%). In contrast, weekly frequency (94.4%), duration (weeks) (100%), number of sets/repetitions (88.9%), repetitions to failure/not to failure (77.8%), types of contraction (77.8%), rest duration (55.6%), progression (55.6%), supervision (77.8%), exercise equipment (72.2%) and adverse event record (77.8%) had a higher percentage of reported (>50% of studies).

CONCLUSION

Future research on strength training for PWH should improve information on pain threshold and other important variables such as prophylactic factor coverage, intensity, range of motion, time under tension, attentional focus modality, therapist experience in haemophilia and adherence assessment. This could improve clinical practice and comparison of different protocols.

Social determinants of health and physical activity are related to pain intensity and mental health in patients with carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy of the upper limb and a frequent cause of disability.

OBJECTIVE

To analyze the association between social determinants of health (SDH) and physical activity with pain intensity and mental health in patients with CTS.

DESIGN

A cross-sectional study was conducted in patients with CTS awaiting surgery in two public hospitals in Chile.

METHODS

The SDH collected included: employment status, educational level and monetary income. The level of physical activity was defined according to compliance with WHO recommendations. Outcome measures included: Pain intensity (Visual Analog Scale), Symptoms of anxiety and depression (Hospital Anxiety and Depression Scale), and catastrophic thinking (Pain Catastrophizing Scale). The adjusted regression coefficient (β) for the association between SDH and physical activity with each outcome was obtained using multivariable linear regression models controlling for age, sex, body mass index and symptom duration.

RESULTS

Eighty-six participants were included (mean age 50.9 ± 10 years, 94% women). A high level of physical activity was associated with a 12.41 mm decrease in pain intensity (β = -12.41, 95%CI: -23.87 to -0.95) and a 3.29 point decrease in depressive symptoms (β = -3.29, 95%CI: -5.52 to -1.06). In addition, being employed was associated with a 2.30 point decrease in anxiety symptoms (β = -2.30; 95%CI: -4.41 to -0.19) and a high educational level was associated with a 7.71 point decrease in catastrophizing (β = -7.71; 95%CI: -14.06 to -1.36).

CONCLUSION

Multidisciplinary care teams should be aware of the association between SDH and physical activity with physical and mental health.

Shoulder vibratory exercises improves shoulder external rotation muscle strength and shoulder function: Randomized comparison trial

BACKGROUND

Based on electromyography measurements, shoulder vibratory exercises efficiently stimulate shoulder muscles activity. Yet very few studies have supported that shoulder vibratory exercises increased shoulder muscles strength and function, and the noninferiority compared with conventional elastic resistance exercises remains unknown.

OBJECTIVE

This study investigated the effect of vibratory exercises versus conventional elastic resistance exercises with elastic bands on shoulder external rotation muscles strength and functional performance in young adults.

METHODS

26 young adults (7 males and 19 females, with age 23.89 ± 3.02) were recruited and randomly allocated to shoulder vibratory exercises with FLEXI-BAR (FLEXI-BAR group) or conventional resistance exercises with elastic band (TheraBand group) for 3 times/week, 4 weeks totally. Shoulder external rotator muscles strength test and Underkofler softball distance throw test (USDTT) were performed before and after the training period.

RESULTS

After 4 weeks training, shoulder external rotator muscles strength increased 22.25 ± 15.06 N (P= 0.004, effect size = 1.48) within FLEXI-BAR group and 22.81 ± 14.94 N (P= 0.007, effect size = 1.53) within TheraBand group. There were no statistically significant differences between groups in the three muscle strength tests (P> 0.65). Regarding shoulder function, FLEXI-BAR exercises increased the throw distance 0.81 ± 0.92 meters in USDTT (P= 0.041, effect size = 0.88) while TheraBand exercise did not (P= 0.284), yet there was no statistically significant between group effects (P= 0.608).

CONCLUSIONS

These findings suggest that shoulder vibratory exercises can improve shoulder muscles strength in young adults and can be a useful alternative to the conventional elastic resistance exercises to improve the shoulder muscles strength and function. This provides therapists with more options in terms of choosing training equipment for rehabilitation programs.

Maintenance effect of corrective exercises on neck-shoulder pain and workability among office workers: A 1-year follow-up

BACKGROUND

While positive short-term effects from corrective exercise on neck-shoulder pain (NSP) are evident, maintenance effects after cessation of the exercise remain unknown.

OBJECTIVE

The objective of the present study was to assess the lasting effects of corrective exercise in NSP and workability after a year of detraining.

METHODS

A cohort study with 1-year follow-up was carried out in two previous training groups (n = 24) using a self-reported paper-based questionnaire, which was completed three times (baseline, 8-week exercise, and 1-year detraining). The subjects (mean±SD age: 39.0±6.4, 38.1±8.0) responded to the Visual Analogue Scale (VAS) for NSP as the primary outcome. A single validated item from the Workability Index determined workability as the secondary outcome. Between and within-group differences of the two groups were investigated using non-parametric tests, including 12 subjects in each group.

RESULTS

The results indicated that 8-week exercise improvements in NSP and mental and physical workability were largely maintained after one year of detraining. The lasting effects of NSP and physical and mental workability were statistically identified in 8-week and 1-year follow-ups. Nevertheless, it is noticeably warranted to adhere to the exercise program.

CONCLUSION

The current study indicates that a brief 8-week exercise period once per year is sufficient to reduce pain and improve workability among workers. This knowledge can make exercise interventions more feasible and cost-effective for companies aiming to improve employee health.

Association of occupational physical activity and disability pension in 756,159 Spanish workers: A prospective cohort study with 13 years follow-up

Recent research from Nordic countries identified occupational physical activity (OPA) as a risk factor for disability pension, but further research accounting for exhaustive analyses in novel populations is warranted. Our objective was to assess the association between OPA and disability pension using administrative data. This prospective registry-based cohort study used data from the Spanish Continuous Working Life Sample (CWLS). Participants were followed up from baseline (January 1, 2006) to first event of disability pension, mortality, or end of follow-up (September 1, 2019). The assessment of OPA was based on registers of economic activity and their correspondence with a validated OPA index. To examine the association between OPA and disability pension, adjusted proportional hazard, and Fine-Gray models using mortality as competing risk were conducted. We retrieved data from 756,159 workers (57.7% men) with an average age of 38.5 years (SD 11.9). During 13.6 years from baseline to the end of follow-up (9,463,041 person-years), 18,191 men (4.2%) and 9631 (3.0%) women received a disability pension. In the fully adjusted model, participants exposed to higher levels of OPA showed higher risk for disability pension in an exposure-response fashion. Men and women exposed to very high OPA showed the highest HR for disability pension (2.31 [95% CI, 2.17 to 2.46] and 1.68 [95% CI, 1.56 to 1.81], respectively. These results warrant preventative measures to address early involuntary exit from the labour market in workers exposed to high physical work demands.

Effectiveness of manual therapy, computerised mobilisation plus home exercise, and home exercise only in treating work-related neck pain: study protocol for a randomised controlled trial

BACKGROUND

Work-related neck pain (WRNP) is a leading cause of disability and absenteeism. Patients with neck pain often have neck muscle tenderness and decreased cervical mobility, which are sometimes combined with psychosocial issues, such as pain catastrophising, thereby reducing their work ability. Whilst multidisciplinary treatments, including pharmacological interventions, manual therapy and specific neck exercises, have produced positive outcomes, effective personalised treatment modalities are still needed. Furthermore, manual therapies using the hands can bring fatigue to therapist. Occiflex is a computerised device that can provide personalised segmental joint mobilisation based on symptoms and injury of the patient and then provide a medium range of joint activities to improve range of cervical motion. This study aims to compare the effect of computerised mobilisation performed with Occiflex with that of traditional manual therapy on WRNP.

METHODS

We will conduct a prospective randomised controlled trial including 150 patients with WRNP. These patients will be randomly assigned to one of three groups: (i) home exercise (TE), (ii) home exercise plus Occiflex therapy and (iii) home exercise plus manual therapy delivered by a physical therapist. Ten treatment sessions will be performed in four weeks. During the trial, these patients will receive only the assigned treatment and the standard patient education and will be asked not to use any analgesics unless strictly necessary. Assessments by trained evaluators will occur at baseline, week 4 and week 12. The primary outcome measures will include visual analogue scale (VAS) for pain and neck disability index (NDI) at each time point. Secondary outcome measures will include cervical range of motion (CROM), pressure pain threshold (PPT), global perceived effect (GPE) and sick leave. Group by time differences will be analysed using linear mixed models with repeated measures.

DISCUSSION

This protocol describes the methods for a randomised controlled trial to compare the effectiveness of computerised versus manual mobilisation techniques in treating WRNP. The results will provide an alternative method (Occiflex) that is possibly effective for treating neck pain whilst minimising the manual work done by therapists.

TRIAL REGISTRATION

The study protocol was retrospectively registered at http://www.chictr.org.cn (registration number: ChiCTR2100053076) on November 10, 2021.

Thresholds of handgrip strength for all-cause, cancer, and cardiovascular mortality: A systematic review with dose-response meta-analysis

BACKGROUND

While handgrip strength is associated with all-cause and cause-specific mortality, whether such associations are dose-dependent is largely unknown. Therefore, we conducted a systematic review on the dose-response relationship of handgrip strength with all-cause mortality, cancer, and cardiovascular mortality.

METHODS

The data source included three electronic databases (PubMed/MEDLINE, Web of Science and Scopus) from inception to 8 February 2022. Prospective cohort studies of healthy adults with objective measures of handgrip strength were included. Two researchers independently screened studies, extracted data, and assessed risk of bias. We used estimates regarding handgrip strength categories to conduct a random forest model, and a two-stage random-effects hierarchical meta-regression model pooling study-specific estimates for dose-response relationship. Outcomes included all-cause, cancer, and cardiovascular mortality.

REULTS

Forty-eight studies comprising 3,135,473 participants (49.6% women, age range 35-85 years) were included. Random forest models showed a significant inverse association between handgrip strength and all-cause and cause-specific mortality. Dose-response meta-analyses showed that higher levels of handgrip strength significantly reduced the risk of all-cause mortality within 26-50 kg (Higgin´s I² =45.7%) in a close-to-linear inverse fashion. Cancer and cardiovascular mortality displayed a trend towards a U-shaped association with a significant risk reduction between 16 and 33 kg (Higgin´s I² =77.4%), and a close-to-linear inverse shaped and significant risk reduction ranging from 24 to 40 kg (Higgin´s I² =79.7%) respectively.

CONCLUSION

There is strong evidence for an association between lower handgrip strength with higher all-cause, cancer, and cardiovascular mortality risk. The dose-response relationship of handgrip strength substantially varies depending on the cause of mortality.

Minimal Dose of Resistance Exercise Required to Induce Immediate Hypotension Effect in Older Adults with Hypertension: Randomized Cross-Over Controlled Trial

To determine the optimal exercise volume to generate a hypotension response after the execution of a single strength exercise in elderly subjects with hypertension (HT), a randomized crossover design was performed. A total of 19 elderly subjects with HT performed one control session and three experimental sessions of resistance training with different volumes in a randomized order: three, six, and nine sets of 20 repetitions maximum (RM) of a single elbow flexion exercise with elastic bands. The systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean heart rate (MHR) were tested at the beginning and immediately afterwards, at 30 and 60 min, and at 4, 5, and 6 h after the resistance exercise. The results show that the volumes of six and nine sets of 20 RM obtained statistically significant differences in the SBP at 30 and 60 min post-exercise (p < 0.05); in the DBP at 30 min after exercise (p < 0.05); and in the MHR immediately after exercise at 30 and 60 min (p < 0.05), compared to a control session. A single resistance exercise with a minimum volume of six sets of 20 RM generated an acute post-exercise antihypertensive response that was maintained for 60 min in elderly people with controlled HT.

Handgrip strength and respiratory disease mortality: Longitudinal analyses from SHARE

BACKGROUND

While the association between handgrip strength and all-cause mortality is more deeply explored, no previous studies have been specifically focused on handgrip strength and respiratory disease mortality. The purpose of the study was to investigate the association between handgrip strength and respiratory disease mortality in a large representative sample.

METHODS

Individuals aged 50 or over from 27 European countries and Israel participated in this longitudinal study. Data on handgrip strength and all-cause and respiratory disease mortality were retrieved from the Survey of Health, Ageing and Retirement in Europe (SHARE) waves 1, 2, 4, 5, 6 and 7. We estimated the sub hazard ratios (SHRs) for respiratory disease mortality using a Fine-Gray sub-distribution method with both time-varying exposure and covariates and mortality due to other causes as competing risk. Furthermore, we assessed dose-response associations of handgrip strength (modelled as a continuous exposure) with respiratory disease mortality using restricted cubic splines and estimated hazard ratios (HRs).

RESULTS

We included 60,883 men and 74,904 women with a mean age of 63.6 (SD 9.7) years at study entry. During a median (interquartile range) of 7.4 years of follow-up 565 (0.4%) participants died due to respiratory diseases. The increase of 1 single kg of handgrip strength showed a 6% incidence reduction on respiratory disease mortality (SHR, 0.94; 95%CI, 0.92-0.96) after adjusting for potential confounders. Furthermore, each kg increase of handgrip strength reduced respiratory disease mortality risk in a dose-response fashion and a significant threshold for values of 41 kg (HR, 0.49; 95%CI, 0.26-0.92) and higher was identified.

CONCLUSIONS

Higher handgrip strength is associated with lower mortality due to respiratory disease. Intervention studies are needed to determine whether strength training in respiratory disease patients can prevent premature mortality.

Longitudinal association of handgrip strength with all-cause and cardiovascular mortality in older adults using a causal framework

To date, there is no study addressing the time-varying confounding bias in the association of handgrip strength (HGS) with all-cause or cardiovascular mortality. Therefore, we conducted marginal structural models (MSM) to provide causal estimations on the associations of HGS with all-cause and cardiovascular mortality in a representative sample of adults aged 50 years or older. Data from 29 countries including 121,116 participants (276,994 observations; mean age 63.7 years; 56.3 % women) free from prior heart attack or stroke were retrieved from consecutive waves of the Survey of Health, Ageing and Retirement in Europe (SHARE). During a median of 7.7 years follow-up (interquartile range 3.8-11.8) and 1,009,862 person-years, 6407 participants (5.3 %) died due to all causes, and 2263 (1.9 %) died due to cardiovascular diseases. Using repeated measures of handheld dynamometry, we determined absolute and relative to body mass index HGS of each participant. We applied adjusted MSM to estimate hazard ratios (HRs) associated with changes over time in HGS addressing the time-varying confounding bias. An increase of 5 kg in HGS was associated with a reduced risk of all-cause [HR 0.86, 95 % confidence interval (CI), 0.86-0.90], overall cardiovascular (HR 0.86, 95 % CI 0.82-0.86), heart attack (HR 0.90, 95 % CI 0.86-0.95), and stroke (HR 0.86, 95 % CI 0.82-0.90) mortality. The associations of relative HGS were of stronger magnitude in all cases. Our findings provide critical evidence on the importance of increasing general muscle strength in older adults to reduce mortality risk, particularly concerning cardiovascular causes.

Barriers and Facilitators of Re-Employment among Senior Workers: Prospective Cohort Study

Re-entering the labour market after a period of unemployment can be challenging for seniors. This study investigates personal as well as circumstantial barriers and facilitators of re-employment. Unemployed seniors in Denmark (≥50 years, n = 1636) from the first wave (mid-2018) of the SeniorWorkingLife study were prospectively followed until March 2020 in national registers on labour market participation. Using weighted logistic-regression-modelled odds ratios (ORs), we estimated the association between personal and circumstantial factors at baseline and re-employment during follow-up. During follow-up, 28% re-entered paid employment. The desire to have a job (reference: not having the desire to have a job) increased the likelihood of re-employment (OR 2.35, 95% CI 1.14-4.85). Contrastingly, a higher age (60-63 vs. 50-54 years; OR 0.36, 95% CI 0.16-0.79) and poor health (OR 0.32, 95% CI 0.16-0.61) decreased the likelihood of re-employment. Sex, education and belief that age constitutes a barrier to re-employment were not associated with the likelihood of re-employment. Unemployed seniors desiring to have a job are more likely to get a job. However, a higher age and poor health are important barriers that should be taken into account, e.g., by ensuring employment opportunities for these groups in society.

Can a Healthy Lifestyle Prevent Disability Pension among Female Healthcare Workers with Good and Poor Self-Rated Health? Prospective Cohort Study with 11-Year Register Follow-Up

BACKGROUND

Our purpose was to investigate whether healthy lifestyle habits prevent disability pension among female healthcare workers.

METHODS

We conducted a prospective cohort study with an 11-year register follow-up in which 8159 female healthcare workers from Denmark completed a questionnaire concerning self-rated health, work environment, leisure-time physical activity (LTPA), smoking, and body mass index (BMI). Data on disability benefit payments were obtained from the Danish Register for Evaluation of Marginalization during an 11-year follow-up. Potential confounders included age, occupational education, psychosocial work factors, and physical exertion during work.

RESULTS

Among workers in good health at baseline, smoking, obesity, and low levels of LTPA were risk factors for disability pension during 11-year follow-up. Among workers with poor health, only low levels of physical activity were a risk factor for disability pension.

CONCLUSIONS

This underscores the importance of a healthy lifestyle, specially being physically active, for preventing premature exit from the labor market in female healthcare workers.

Work ability and physical activity after major bone sarcoma resection and reconstruction with tumour prosthesis of the lower extremities. A cross-sectional study

PURPOSE

The aim of this study was to evaluate work ability, activity limitations and physical activity in adults that had gone through major bone sarcoma resection and reconstruction surgery in hip and knee.

MATERIALS AND METHODS

Twenty patients, of 72 enrolled, and 20 controls were included in this cross-sectional study. Work Ability Index scores (general [0-10 points], physical and mental [1-5 points]), the Patient Specific Functional Scale (0-10 points), step counts and the International Physical Activity Questionnaire (IPAQ) were assessed. Adjusted and unadjusted general linear models were applied.

RESULTS

The patients had a mean age of 43 (range, 20-71) years and were assessed 7 years (range, 2-12) after surgery (proximal femoral n = 9, distal femoral n = 7, proximal tibia n = 4). Compared with controls, patients had lower general work ability (mean difference [95%CI], -1.3 points [-2.1, -0.5]) and work ability in relation to physical demands at work (-1.4 points [-2.0, -0.8]). The patients reported higher severities of activity limitation (-6.7 points [-7.9, -5.4]). There were no between-group differences in step counts or IPAQ-scores.

CONCLUSION

Despite similar levels of physical activity, patients showed poorer work ability and severe activity limitation. Post-operative rehabilitation in patients of the working-age population should include assessments of work ability and activities important to the individual.IMPLICATIONS FOR REHABILITATIONAdults that have gone through resection and reconstruction surgery following bone sarcoma in lower extremity show clinically relevant reductions in work ability and self-selected activitiesTo tailor post-operative rehabilitation at short and long term, initial assessment and monitoring should include work ability and activities important to the individual patient.

Associations of handgrip strength with all-cause and cancer mortality in older adults: a prospective cohort study in 28 countries

Background

mixed evidence exists on the association between muscle strength and mortality in older adults, in particular for cancer mortality.

Aim

to examine the dose–response association of objectively handgrip strength with all-cause and cancer mortality.

Study Design and Setting

data from consecutive waves from the Survey of Health, Ageing and Retirement in Europe comprising 27 European countries and Israel were retrieved. Overall, 54,807 men (45.2%; 128,753 observations) and 66,576 women (54.8%; 159,591 observations) aged 64.0 (SD 9.6) and 63.9 (SD 10.2) years, respectively, were included. Cox regression and Fine-Grey sub-distribution method were conducted.

Results

during the follow-up period (896,836 person-year), the fully adjusted model showed the lowest significant risk estimates for the highest third of handgrip strength when compared with the first third (reference) in men (hazard ratio [HR], 0.41; 95% confidence interval [CI], 0.34–0.50) and women (HR, 0.38; 95% CI, 0.30–0.49) for all-cause mortality. We identified a maximal threshold for reducing the risk of all-cause mortality for men (42 kg) and women (25 kg), as well as a linear dose–response association in participants aged 65 or over. No robust association for cancer mortality was observed.

Conclusion

these results indicate an inverse dose–response association between incremental levels of handgrip and all-cause mortality in older adults up to 42 kg for men and 25 kg for women, and a full linear association for participants aged 65 years or over. These findings warrant preventive strategies for older adults with low levels of handgrip strength.

Corrective exercises administered online vs at the workplace for pain and function in the office workers with upper crossed syndrome: randomized controlled trial

Objective

To evaluate the effects of online-supervised versus workplace corrective exercises on neck–shoulder pain (NSP), sick leave, posture, workability, and muscular activity among office workers with the upper crossed syndrome (UCS).

Methods

We performed a parallel-group randomized control trial at Shahid Beheshti University, Tehran, Iran, assigning 36 office workers to online-supervised, workplace, and control groups (mean (SD) age 38.91 ± 3.87, 38.58 ± 7.34, 37.00 ± 8.12). Inclusion criteria were alignment alteration (forward head (≥ 45°), rounding shoulder (≥ 52°), rounding back (≥ 42°), and pain intensity ≥ 3 in neck and shoulder. The two intervention groups performed 8-week exercise program, while the control group continued usual activities. Primary (NSP and sick leave) and secondary outcomes [postural angles, workability, and muscular activity were measured by VAS, outcome evaluation questionnaire (OEQ), photogrammetry, workability index, and EMG, respectively, at the baseline and an 8-week follow-up].

Results

ANCOVA results revealed improvements for the online-supervised group versus control for NSP (P = 0.007), postural angles (P = 0.000, P = 0.001, P = 0.005), workability (P = 0.048, P = 0.042), and upper trapezius activation (P = 0.024, P = 0.016), respectively. Using paired t tests, both intervention groups improved from baseline to follow-up for NSP (P = 0.000, P = 0.002), forward head posture (P = 0.000, P = 0.000), round shoulders (P = 0.001, P = 0.031), and round back (P = 0.034, P = 0.008), respectively. Related parameters of workability (P = 0.041, P = 0.038), upper trapezius (P = 0.005, P = 0.005, P = 0.022), and serratus anterior (P = 0.020, P = 0.015) changed only in the online-supervised group.

Conclusion

Online-supervised corrective exercise seems to improve a range of parameters related to work performance. These findings are highly applicable in light of the ongoing COVID pandemic; many workers have to work from home.

The unexplored role of sedentary time and physical activity in glucose and lipid metabolism-related placental mRNAs in pregnant women who are obese: the DALI lifestyle randomised controlled trial

OBJECTIVE

We aimed to explore: (i) the association of sedentary time (ST) and physical activity (PA) during pregnancy with the placental expression of genes related to glucose and lipid metabolism in pregnant women who are obese; (ii) maternal metabolic factors mediating changes in these placental transcripts; and (iii) cord blood markers related to the mRNAs mediating neonatal adiposity.

DESIGN

Multicentre randomised controlled trial.

SETTING

Hospitals in nine European countries.

POPULATION

A cohort of 112 pregnant women with placental tissue.

METHODS

Both ST and moderate-to-vigorous PA (MVPA) levels were measured objectively using accelerometry at three time periods during pregnancy.

MAIN OUTCOME MEASURES

Placental mRNAs (FATP2, FATP3, FABP4, GLUT1 and PPAR-γ) were measured with NanoString technology. Maternal and fetal metabolic markers and neonatal adiposity were assessed.

RESULTS

Longer periods of ST, especially in early to middle pregnancy, was associated with lower placental FATP2 and FATP3 expression (P < 0.05), whereas MVPA at baseline was inversely associated with GLUT1 mRNA (P = 0.02). Although placental FATP2 and FATP3 expression were regulated by the insulin-glucose axis (P < 0.05), no maternal metabolic marker mediated the association of ST/MVPA with placental mRNAs (P > 0.05). Additionally, placental FATP2 expression was inversely associated with cord blood triglycerides and free fatty acids (FFAs; P < 0.01). No cord blood marker mediated neonatal adiposity except for cord blood leptin, which mediated the effects of PPAR-γ on neonatal sum of skinfolds (P < 0.05).

CONCLUSIONS

In early to middle pregnancy, ST is associated with the expression of placental genes linked to lipid transport. PA is hardly related to transporter mRNAs. Strategies aimed at reducing sedentary behaviour during pregnancy could modulate placental gene expression, which may help to prevent unfavourable fetal and maternal pregnancy outcomes.

TWEETABLE ABSTRACT

Reducing sedentary behaviour in pregnancy might modulate placental expression of genes related to lipid metabolism in women who are obese.

Online supervised versus workplace corrective exercises for upper crossed syndrome: a protocol for a randomized controlled trial

Background and objective

Musculoskeletal disorders (MSDs) including upper crossed syndrome (UCS) are considered as the leading cause of work-related issues worldwide among office workers. Therefore, the present study aims to evaluate the effect of workplace-based versus online-supervised home-based corrective exercises among office workers with UCS.

Methods and design

To this end, 45 subjects within the age range of 30–45 years are randomly assigned to three groups in the present parallel-group, randomized control trial using a pretest-posttest design. These groups include the subjects who receive online-supervised exercise and workplace exercise containing three sessions of intervention for 8 weeks and the control group receives no intervention while performing routine activities. The primary outcome variables are neck-shoulder pain (NSP) and consequent sick leave due to NSP, followed by alignment, workability, and the surface electromyography of upper, middle, and lower trapezius (UT, MT, and LT), sternocleidomastoid (SCM), and serratus anterior (SA) as the secondary variables.

Discussion

The present study seeks to assess the effect of workplace versus online-supervised corrective exercise interventions among 45 office workers suffering from UCS. It is expected to improve and reduce the related symptoms including postural malalignment and imbalance muscles after 8 weeks of corrective exercises. If effective, the findings may lead to adherence and work performance among the office workers, and individuals subjected to UCS can use the benefits of an online-supervised intervention. In addition, the findings may be useful in different workplaces as the evidence for employers to benefit from the reduction in the related costs and side effects of work-related neck/shoulder disorders including work disability, productivity loss, time expense, social insurance, work absenteeism, and treatment costs. Finally, clinicians and corrective exercise therapists can consider it as a clinical based-evidence intervention for their further actions.

Trial registration

Iranian Registry of Clinical Trials IRCT20200729048249N1. Registered on 5 October 2020 (https://en.irct.ir/user/trial/49992/view)

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.

Acute cardiovascular stress induced by shoulder vibratory exercise of different amplitudes

BACKGROUND

Vibration exercise has been investigated to enhance muscle activation, however, the effect of different amplitude vibratory exercises on cardiovascular stress is less understood.

OBJECTIVE

Our study aims to explore the acute effect of shoulder vibratory exercises with different postures and amplitudes on the cardiovascular response in healthy adults.

METHODS

Using a repeated measures randomized design, 36 subjects performed three different sessions with FLEXI-BAR exercise (FBE): (1) zero-amplitude, (2) small-amplitude, (3) large-amplitude. Each session included three different shoulder positions: 45-, 90- and 180-degree flexion. Heart rate variability (HRV), heart rate (HR) and rating of perceived exertion (RPE) were monitored continuously, while systolic blood pressure (SBP), diastolic blood pressure (DBP) and rate-pressure product (RPP) were measured before and after each exercise session.

RESULTS

Compared with zero-amplitude, both small- and large-amplitude FBE protocols induced higher SBP. By contrast, DBP decreased with small- and large-amplitude. The RPP immediately after the exercise session were higher than at baseline. For high frequency, low frequency of HRV and HR there was a main effect of amplitude.

CONCLUSION

Small- and large-amplitude FBE increased significantly SBP, RPE, HRV, HR and induced lower DBP, but the changes were modest, suggesting that FBE impose no extra threats to cardiovascular stress.

Musculoskeletal pain intensity in different body regions and risk of disability pension among female eldercare workers: prospective cohort study with 11-year register follow-up

Background

Musculoskeletal pain is a risk factor for leaving the labour market temporarily and permanently. While the presence of multi-site pain increases the risk of disability pension, we lack detailed knowledge about pain intensity as a risk factor. This study investigated the association between musculoskeletal pain intensity in different body regions and risk of future disability pension among eldercare workers.

Methods

Eight thousand seven hundred thirty-one female eldercare workers replied to a questionnaire on work and health in 2005 and were followed for 11 years in the Danish Register for Evaluation of Marginalization. Time-to-event analyses estimated hazard ratios (HR) for disability pension from pain intensities (0–9 numeric rating scale (NRS)) in the low-back, neck/shoulders, and knees during the previous 3 months. Analyses were mutually adjusted for pain regions, age, education, lifestyle, psychosocial work factors, and physical exertion at work.

Results

During 11-year follow-up, 1035 (11.9%) of the eldercare workers received disability pension. For all body regions among all eldercare workers, dose-response associations were observed between higher pain intensity and risk of disability pension (p < 0.001). The risk for disability pension was increased when reporting “very high” pain levels (≥7 points on the 0–9 NRS) in the low-back (HR 2.19, 95% CI 1.70–2.82), neck/shoulders (HR 2.34, 95% CI 1.88–2.92), and knees (HR 1.89, 95% CI 1.44–2.47). Population attributable risks (PAR) were 15.5, 23.2, and 9.6% for pain > 2 on NRS in the low-back, neck/shoulders, and knees, respectively, indicating that 15.5, 23.2, and 9.6% fewer eldercare workers would likely receive disability pension if the pain intensity was reduced to 2 or less. For workers ≤45 years and > 45 years, PAR was highest for neck/shoulder pain (27.6%) and low-back pain (18.8%), respectively.

Conclusions

The present study found positive dose-response associations between pain intensity in the low-back, neck/shoulders, and knees, and risk of disability pension during 11-year follow-up. Moderate to very high levels of musculoskeletal pain in eldercare workers should, therefore, be considered an early warning sign of involuntary premature exit from the labour market. These findings underscore the importance of preventing, managing, and reducing musculoskeletal pain to ensure a long and healthy working life.

Cross-sectional Study of EMG and EMG Rise During Fast and Slow Hamstring Exercises

BACKGROUND

Hamstring injuries remain a major burden in football while the effective prevention exercise the Nordic Hamstring is poorly adopted, despite the added positive effects on performance. Better understanding of hamstring function during Nordic Hamstring compared to other exercises may provide better insight to the physiological adaptations of different types of hamstring curls.

PURPOSE

This cross-sectional study therefore aimed to compare the Nordic Hamstring curl with a conventional prone Leg Curl at different loads, and novel high velocity Hamstring Catches; in terms of peak normalized electromyographical activity (nEMG) and rate of electromyographic rise (RER) of Biceps Femoris long head, and angular velocity of the knee.

STUDY DESIGN

Cross-sectional study.

METHODS

Out of 28 participants enrolled, the final sample included 23 recreationally active male participants who attended a session for determining RM (repetition maximum) to establish loading (8 and 16RM for Hamstring Catches, and 8, 16 and 24RM for Leg Curl) and to familiarize themselves with the three different exercises (Nordic Hamstring, Leg Curl and Hamstring Catch), and a testing session >4 days after during which EMG data were collected during 3 repetitions of each exercise performed in a random order.

RESULTS

The Nordic Hamstring evoked higher RER (1091.8 nEMG/s) than Hamstring Catches (mean difference: 421 nEMG/s, p<0.0001) and Leg Curl (mean difference: 705 nEMG/s, p<0.001), and at the earliest numerical timepoint from onset of muscle contraction (the Nordic Hamstring: 6 ms; Hamstring Catches: 36-41 ms; Leg Curl: 12-14 ms). Hamstring Catches displayed high peak angular velocity (mean: 471°/s). There was no difference in peak nEMG, irrespective of load for Leg Curl (8, 16 or 24RM) or Hamstring Catches (8- or 16RM).

CONCLUSION

The Nordic Hamstring displayed the highest level muscle activity and most explosive recruitment characteristics with early and high rate of electromyographic rise, compared to even high velocity exercises, thus providing a possible mechanism by which it may increase performance and reduce injuries.

LEVELS OF EVIDENCE

3.

WHAT IS KNOWN ABOUT THE SUBJECT

Early phase force and muscle recruitment have been linked to both performance and hamstring-related inhibition and fatiguability. However, the potential for different hamstring exercises to elicit explosive recruitment is unknown.

WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE

Early phase recruitment was higher and faster during the Nordic Hamstring exercise compared with conventional hamstring Leg Curl exercises with different loads and a high-velocity hamstring exercise.

CLINICAL RELEVANCE

The surprisingly fast and explosive recruitment characteristics during the Nordic Hamstring exercise suggests the possibility that this exercise have the potential to improve the rate of force development and perhaps counter the effects of hamstring-related inhibition and fatigue.

Self-reported sickness absence and presenteeism as predictors of future disability pension: Cohort study with 11-year register follow-up

Many healthcare workers in eldercare are pushed out of the labor market before the official retirement age due to poor health. Identification of early warnings signs is important to avoid complete loss of work ability. The aim of this study was to investigate to what degree sickness absence and presenteeism increase future risk for disability pension among eldercare workers. A total of 8952 Danish female eldercare workers responded to a survey about work environment and health. They were followed for 11 years in the Danish Register for Evaluation of Marginalization, with time-to-event analyses estimating the hazard ratios (HRs) for disability pension from sickness absence and presenteeism at baseline. Analyses were adjusted for age, education, body mass index, leisure-time physical activity, smoking, physical exertion at work, and psychosocial factors related to the work environment. During the 11-year follow-up, 11.9% participants received disability pension. For the whole cohort, the highest risk for disability pension was observed for the category of >30 days of combined sickness absence and presenteeism at baseline in the fully adjusted model (HR = 7.93 [95%CI 5.20-12.09]). Eldercare workers aged >45 years were at a higher risk for disability pension in all included categories. Sickness absence and presenteeism increased the risk of disability pension among female eldercare workers. These results suggest that organizations would benefit from identifying early warning signs among workers in the prevention of involuntary early retirement.

High physical work demands have worse consequences for older workers: prospective study of long-term sickness absence among 69 117 employees

Objective

This study investigates the role of age for the prospective association between physical work demands and long-term sickness absence (LTSA).

Methods

We followed 69 117 employees of the general working population (Work Environment and Health in Denmark study 2012–2018), without LTSA during the past 52 weeks preceding initial interview, for up to 2 years in the Danish Register for Evaluation of Marginalisation. Self-reported physical work demands were based on a combined ergonomic index including seven different types of exposure during the working day. Using weighted Cox regression analyses controlling for years of age, gender, survey year, education, lifestyle, depressive symptoms and psychosocial work factors, we determined the interaction of age with physical work demands for the risk of LTSA.

Results

During follow-up, 8.4% of the participants developed LTSA. Age and physical work demands interacted (p<0.01). In the fully adjusted model, very high physical work demands were associated with LTSA with HRs of 1.18 (95% CI 0.93 to 1.50), 1.57 (95% CI 1.41 to 1.75) and 2.09 (95% CI 1.81 to 2.41) for 20, 40 and 60 years old (point estimates), respectively. Results remained robust in subgroup analyses including only skilled and unskilled workers and stratified for gender.

Conclusion

The health consequences of high physical work demands increase with age. Workplaces should consider adapting physical work demands to the capacity of workers in different age groups.

Can high workplace social capital buffer the negative effect of high workload on patient-initiated violence? Prospective cohort study

BACKGROUND

High workload seems to increase the risk of patient-initiated workplace violence (patient-initiated violence). However, the temporal association between workload and violence remains uncertain. Understanding the interplay of factors in the psychosocial working environment and patient-initiated violence is important to future preventive initiatives.

AIM

To assess whether a high workload increases the risk of patient-initiated violence, and whether intraorganizational relationships based on trust, reciprocity, justice and collaboration, known as workplace social capital, moderate this risk.

METHOD

Baseline survey data on 1823 social educators was collected followed by 12 monthly surveys on patient-initiated violence exposure. Poisson regressions, in mixed models, were conducted to assess the risk of violence at four levels of workload. Further, moderation analyses were conducted to assess the moderating effects of three sub-types of workplace social capital.

RESULTS

High and very high workload increased the risk of patient-initiated violence: RR = 1.5 [1.4-1.6], p < .001 and RR = 1.4 [1.3-1.4], p < .001. All three levels of workplace social capital had a moderating effect on the workload-violence association: Workload*Workplace social capital_(co-worker): F (3, 16,712) = 3.4, p = .017, Workload*Workplace social capital_{(local management)}: F (3, 16,748) = 11.9, p < .001, Workload*Workplace social capital_{(general management)}: F (3, 16,556) = 5.5, p < .001. Only high Workplace social capital _(co-workers) reduced the risk of violence at all levels of workload. Workplace social capital _{(general management)} reduced the risk of violence at high, medium and low workload, and Workplace social capital _{(local management)} reduced the risk of violence at medium and low workload.

CONCLUSION

High workload clearly increases the risk of patient-initiated violence. A high workplace social capital appears to be a viable protective factor and should be investigated further in studies of patient-initiated violence prevention.

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.

Manual material handling in the supermarket sector. Part 2: Knee, spine and shoulder joint reaction forces

Manual material handling is common in supermarkets and may be a contributing factor to the high prevalence of work-related musculoskeletal disorders, particularly to the lower back. This cross-sectional study applied state-of-the-art musculoskeletal models driven by kinematic data obtained in two supermarkets to estimate joint reaction forces in the knees, shoulders and lumbar spine under dynamic lifting conditions. Based on 1479 lifts from 15 workers, 8 tasks for which the compression or shear forces in the L5-S1 joint exceeded well-known biomechanical tolerance limits were identified. High shoulder forces were associated with lifting relatively heavy merchandise to high shelves, while the weight of the handled merchandise was the main predictor of high knee forces. The study addressed well-known limitations associated with traditional lifting analysis tools and was the first to present a detailed analysis of the biomechanical loads during manual material handling tasks in the supermarket sector based on field measurements.