Heavy manual work throughout the working lifetime and muscle strength among men at retirement age

Occupational characteristics and disability-free survival after retirement age: an exploratory analysis from the ASPREE study

Background

Certain occupational characteristics have been linked with poor health and reduced longevity. However, the association between occupational characteristics and survival free of disability in a post-retirement age group has not been investigated.

Methods

We investigated outcomes in 12,215 healthy older Australian adults in the Aspirin in Reducing Events in the Elderly (ASPREE) and ASPREE Longitudinal Study of Older Persons (ALSOP) sub-study. The ISCO-88 major occupational groups, settings, and activity levels were assigned based on free-text job descriptions. The Finnish Job Exposure Matrix was used to assign occupational characteristics to the three longest-held jobs. The primary endpoint, disability-free survival, was defined as a composite measure of death, dementia, or persistent physical disability. The endpoint of all-cause mortality was analyzed separately. Because of multiple exploratory analyses, only those associations with a two-sided value of p less than 0.005 were considered statistically significant. Cox proportional hazard models were used to calculate adjusted hazard ratios.

Results

Having worked in an 'elementary' occupation was associated with a reduction in disability-free survival. A specific impact on disability-free survival was observed among those whose work had involved high accident risk and adverse social climate. No significant relationship was identified with those previously exposed to sedentary work, vigorous physical activity, work primarily outdoors, or a range of other occupational characteristics. All-cause mortality was not increased among any of the occupational groups.

Conclusion

This exploratory study found a reduction in disability-free survival among people who worked in 'elementary' occupations, with specific risks associated with occupations involving high accident risks and adverse social climate.

Exercise-based intervention as a nonsurgical treatment for patients with carpal instability: A case series

BACKGROUND

Although the important roles of proprioception and neuromuscular control in carpal instabilities under laboratory conditions have been recognized, only a few studies have translated this knowledge into a routine clinical practice.

PURPOSE

This study aimed to evaluate the results of a personalized rehabilitation in patients with carpal instability on functionality and pain intensity.

STUDY DESIGN

This was a case series study.

METHODS

This case series included 39 adults (mean age: 38.2 ± 14.0 years; 16/23 females/males) diagnosed with carpal instability (radial or ulnar) with indication for orthopedic treatment. The disabilities of the arm, shoulder, and hand questionnaire was used to assess upper limb functionality. Pain perception was assessed using a visual analog scale. Exercise-based physiotherapy interventions were performed according to the clinical needs of the patients for at least 6 weeks (2-3 sessions per week). For the treatment of radial instability (n = 13), strengthening exercises of the abductor pollicis longus, extensor carpi radialis longus, flexor carpi radialis, and pronator quadratus muscles were prescribed. For the treatment of ulnar instability (n = 24), extensor carpi ulnaris and pronator quadratus were trained. All patients underwent proprioceptive training in open kinetic chain and closed kinetic chain, as well as strengthening of the unaffected hand. Changes before and after treatment were compared using the nonparametric Wilcoxon signed rank test.

RESULTS

A significant improvement with a large effect size in disabilities of the arm, shoulder, and hand (P < .001; d = 2.9) and visual analog scale (P < .001; d = 3.2) scores were obtained after treatment. Moreover, the changes were greater than the minimal clinically important difference of 10.8 and 1.4, respectively. Similar results were found when patients with radial instability and ulnar instability were analyzed separately.

CONCLUSIONS

Personalized training with specific proprioception and strengthening exercises produces improvements in functionality and pain perception in our cohort of people with carpal instability. These results highlight the importance of multicomponent exercise in the treatment of wrist instability. Future randomized clinical trials should further investigate the effectiveness of this protocol.

Associations between childhood and adulthood socioeconomic position and grip strength at age 46 years: findings from the 1970 British Cohort Study

BACKGROUND

Muscle weakness is a key criterion for important age-related conditions, including sarcopenia and frailty. Research suggests lower childhood socioeconomic position (SEP) may be associated with muscle weakness in later life but there is little evidence on associations in younger adults closer to peak muscle strength. We aimed to examine relationships between indicators of SEP in childhood and adulthood and grip strength at age 46y.

METHODS

We examined 7,617 participants from the 1970 British Cohort Study with grip strength measurements at 46y. We used sex-specific linear regression models to test associations between five different indicators of SEP in childhood and adulthood (paternal occupational class and parental education levels at age 5 and own occupational class and education level at age 46) and maximum grip strength. Models were adjusted for birth weight, BMI in childhood and adulthood, adult height, disability in childhood, leisure-time physical activity in childhood and adulthood, sedentary behaviour in childhood and adulthood, occupational activity and smoking at age 46.

RESULTS

Among women, lower SEP in childhood and adulthood was associated with weaker grip strength even after adjustments for covariates. For example, in fully-adjusted models, women whose mothers had no qualifications at age five had mean grip strength 0.99 kg (95% CI: -1.65, -0.33) lower than women whose mothers were educated to degree and higher. Among men, lower levels of father's education and both adult SEP indicators were associated with stronger grip. The association between own occupational class and grip strength deviated from linearity; men in skilled-manual occupations (i.e. the middle occupational group) had stronger grip than men in the highest occupational group (Difference in means: 1.33 kg (0.60, 2.06)) whereas there was no difference in grip strength between the highest and lowest occupational groups. Adjustment for occupational activity largely attenuated these associations.

CONCLUSION

Findings highlight the need to identify age and sex-specific interventions across life to tackle inequalities in important age-related conditions related to weakness.

Investigation of hand muscle fatigue and its influential factors in manual tasks

Muscle fatigue (MF) can lead to musculoskeletal disorders (MSDs) in the long term; however, it can be managed if the causes are well known. This study aimed to examine the grip force (GF) and grip fatigue (GFa) of employees with light, moderate and heavy manual tasks using a dynamometer and find their possible relationship with other factors. The nature of heavy manual tasks led to more experience of GFa and GF of the right hand. Moreover, the equal need for both hands in occupations with light and moderate manual tasks is the reason for more GFa in the left hand. In this primary study, the height, weight and age of subjects and their exposure to vibration had a decisive effect on GF. In order to determine the accurate effects of the aforementioned risk factors on MF, it is recommended for future studies to be performed on larger populations.

The association between occupational categories and grip strength in Korean male workers

PURPOSE

This study explored the association between occupational categories and muscle strength using handgrip strength (HGS) while considering sociodemographic and health-related factors in Korean men using a national survey.

METHODS

Using cross-sectional data of 8380 men (59.9 ± 16.6 years of age), the occupational categories held the longest duration and HGS levels (normal vs. weak) were determined. Logistic regression was applied with adjustment for sociodemographic factors, work-related factors (working hours and schedule), and health-related factors (physical activity, sedentary time, resistance exercise, alcohol consumption, smoking status, chronic illness, subjective health status, weight category, metabolic syndrome, and protein intake).

RESULTS

Weak HGS prevalence was lowest in male managerial or professional workers (1.5%) and highest in male skilled agricultural, forestry, fishery, or craft and the related trades workers (16.4%). Compared to male managerial or professional workers, the odds for weak HGS increased in male service/sales workers (OR 2.41; 95% CI 1.45-3.99) and male manual workers [agricultural/forestry/fishery/craft and related trades workers, OR 2.94 (95% CI 1.78-4.83); equipment/machine operating/assembling workers, OR 1.68 (95% CI 1.05-2.71); and elementary workers, OR 3.43 (95% CI 1.95-6.05)] in the fully adjusted model. Regardless of age groups, income, working hours, strength exercise, and sedentary time levels, and chronic illness and metabolic syndrome status, male manual workers were more likely to have weak HGS compared to male non-manual workers.

CONCLUSION

Male manual workers may have a higher risk for weak muscle strength compared to male non-manual workers regardless of sociodemographic, work-related, and health-related factors.

Maximum handgrip strength as a function of type of work and hand-forearm dimensions

BACKGROUND

Handgrip strength is a measurement of upper extremity functionality and an indicator of overall physical ability.

OBJECTIVES

The objective of this study was to compare maximum handgrip strength (MGS) between manual workers and office employees and to investigate if the expected difference is related to the anthropometric dimensions of the workers' hands and forearms.

METHODS

This was a cross-sectional study with a sample of 1740 male workers (905 light manual workers; and 835 office employees), aged 20-64 years. Maximum voluntary contractions were obtained using a JAMAR dynamometer according to the methodology proposed by the American Society of Hand Therapy (ASHT). The highest value obtained from three trials was considered as the MGS for each side. Six anthropometric dimensions (i.e., hand length, palm length, forearm length, hand breadth, wrist circumference and forearm circumference) were measured by digital caliper and tape measure.

RESULTS

Maximum handgrip strength of light manual workers (52.7±8.5 kg) was significantly higher than that of office employees (47.3±8.4 kg) (p < 0.001). Maximum handgrip strength was positively correlated with Hand breadth (r = 0.781 for light manual workers and r = 0.766 for office employees; p < 0.001) and Forearm circumference (r = 0.741 for light manual workers and r = 0.752 for office employees; p < 0.001); the only dimensions which were significantly different between the two studied job groups.

CONCLUSIONS

The results of this study revealed that light manual workers are approximately 12.4% stronger than office employees in terms of maximum handgrip force. It is therefore imperative to consider the observed differences in clinical, workstations, and hand tool designs in order to increase efficiency and comfort at work.

Education, occupation and operational measures of sarcopenia: Six years of Australian data

OBJECTIVES

To examine associations of education and occupation with handgrip strength (HGS), lower limb strength (LLS) and appendicular lean mass (ALM).

METHODS

Measures of HGS, LLS and ALM (dual-energy X-ray absorptiometry) were ascertained at baseline in 1090 adults (50-80 years, 51% women), ~3 and 5 years. Education and occupation were self-reported, the latter categorised as high-skilled white collar (HSWC), low-skilled white collar (LSWC) or blue collar. Separate general estimating equations were performed.

RESULTS

The highest education group had greater HGS than the middle (0.33 psi) and lowest (0.48 psi) education groups, and 0.34 kg greater ALM than the lowest education group. HGS was 0.46 psi greater for HSWC than LSWC groups. Compared to LSWC groups, LLS was 5.38 and 7.08 kg greater in HSWC and blue-collar groups. Blue-collar and HSWC groups each had ~ 0.60-0.80kg greater ALM than LSWC.

CONCLUSION

Progressive muscle loss can be prevented by targeted intervention; thus, we suggest clinical attention be directed towards specific social groups.

The Hertfordshire Cohort Study: an overview

The Hertfordshire Cohort Study is a nationally unique study of men and women born in the English county of Hertfordshire in the early part of the 20 ^th century. Records that detail their health in infancy and childhood have been preserved, their sociodemographic, lifestyle, medical and biological attributes have been characterised in later life, and routinely collected data on their hospital use and mortality have been acquired. This paper provides an overview of the study since its inception in the 1980s, including its methods, findings, and plans for its future.

Frailty, prefrailty and employment outcomes in Health and Employment After Fifty (HEAF) Study

OBJECTIVES

Demographic changes are requiring people to work longer. No previous studies, however, have focused on whether the 'frailty' phenotype (which predicts adverse events in the elderly) is associated with employment difficulties. To provide information, we assessed associations in the Health and Employment After Fifty Study, a population-based cohort of 50-65-year olds.

METHODS

Subjects, who were recruited from 24 English general practices, completed a baseline questionnaire on 'prefrailty' and 'frailty' (adapted Fried criteria) and several work outcomes, including health-related job loss (HRJL), prolonged sickness absence (>20 days vs less, past 12 months), having to cut down substantially at work and difficulty coping with work's demands. Associations were assessed using logistic regression and population attributable fractions (PAFs) were calculated.

RESULTS

In all, 3.9% of 8095 respondents were classed as 'frail' and 31.6% as 'prefrail'. Three-quarters of the former were not in work, while 60% had left their last job on health grounds (OR for HRJL vs non-frail subjects, 30.0 (95% CI 23.0 to 39.2)). Among those in work, ORs for prolonged sickness absence, cutting down substantially at work and struggling with work's physical demands ranged from 10.7 to 17.2. The PAF for HRJL when any frailty marker was present was 51.8% and that for prolonged sickness absence was 32.5%. Associations were strongest with slow reported walking speed. Several associations were stronger in manual workers than in managers.

CONCLUSIONS

Fried frailty symptoms are not uncommon in mid-life and are strongly linked with economically important adverse employment outcomes. Frailty could represent an important target for prevention.

Determinants of Grip Strength in Tunisian Nurses: A Bicentric Study

Background

Grip muscle force has always been used to assess functional limitations in elderly. Its use as a tool to assess work capacity has never been described in the literature.

Objective

To describe the patent determinants of grip strength and the usefulness of its measurement in assessing workability index in the healthcare sector.

Methods

This is a cross-sectional study conducted in a sample of 293 healthcare workers representative of 1181 based on a comprehensive questionnaire about socio-professional characteristics and on an 8-item work capacity evaluation (WAI). Besides, Body mass index was measured and muscle strength was assessed by JAMAR hydraulic dynamometer.

Results

Handgrip Strength was stronger in male nurses (p < 0.001), with low perceived physical load (p = 0.0001) and working on a night shift (p = 0.001). It decreased with a greater duration of household work (p < 0.0001) and increased with a greater BMI (p = 0.015) and a better workability index (p < 0.0001). After removal of all the variables that were not independently associated with the muscle strength force, factors accounting for 52.6% of the variance in nurses handgrip strength were gender (p < 0.001), workability index (p < 0.001), duration of household work (p = 0.021), BMI (p = 0.002), perceived physical load (p < 0.001) and work schedule (p = 0.002).

Conclusion

Grip Strength Test is a useful tool to assess strength and functional capacity at work in healthcare workers. Further longitudinal studies are required to confirm this hypothesis.