The Effect of Aging on Physical Performance Among Elderly Manual Workers: Protocol of a Cross-Sectional Study

Adherence to the physical activity guideline beyond the recommended minimum weekly amount: impacts on indicators of physical function in older adults

Introduction

The extent to which additional health benefits of accumulating twice the minimum amount of time in moderate-to-vigorous physical activity (MVPA) affects indicators of physical function in older adults is unclear. Therefore, the aim of the present study was to assess indicators of physical function in older adults who accumulate at least 150 but less than 300 min/week of MVPA compared to those accumulating at least 300 min/week.

Methods

Indicators of physical function, including handgrip strength, 5 times sit-to-stand test (5-STS), squat jump and 6-min walk test (6MWT) were assessed in a sample of 193 older men (n = 71, 67 ± 2 years), and women (n = 122, 67 ± 2 years), who all accumulated at least 150 weekly minutes of MVPA. Time in MVPA was assessed by accelerometry during 1 week and engagement in muscle strengthening activities (MSA) was assessed by self-report. Protein intake was assessed by a food-frequency-questionnaire. Participants were classified as physically active (≥150 but <300 min of MVPA per week) or as highly physically active (≥300 min of MVPA per week).

Results

Factorial analysis of variance revealed that older adults accumulating at least 300 min of MVPA per week had a significantly (p < 0.05) better 6MWT performance and overall physical function compared to the less active group. These findings remained significant after further adjustment for MSA, sex, waist circumference and protein intake. In contrast, no significant differences in indicators of muscle strength were observed between the two groups.

Discussion

Adherence to twice the recommended minimum amount of weekly MVPA time is related to a better physical function, evidenced by a better walking performance compared to adherence to the minimum weekly amount of MVPA. This finding emphasizes the benefits of accumulating daily MVPA beyond the minimum recommended amount to optimize the ability to perform activities of daily living, thus reducing the burden of physical disability and related health-care costs.

How Social Media Use at Work Affects Improvement of Older People's Willingness to Delay Retirement During Transfer From Demographic Bonus to Health Bonus: Causal Relationship Empirical Study

Background

With the increased older population in China and the subsequent reduced labor force, the “demographic bonus” is disappearing. The Chinese government proposed a Healthy China strategy in 2017. The transfer of the demographic bonus to a “health bonus” extended the working life of people and reduced the negative impact of the population’s aging on the labor force structure.

Objective

This research focuses on the effect of older workers’ social media usage at work on their work ability (related to both physical and mental health) and thus their willingness to delay retirement.

Methods

The questionnaire respondents were older than 55 years, and they obtained the questionnaire from social media, from June to July 2018. A total of 1020 valid questionnaires were collected, and SmartPLS 3.28 (SmartPLS GmbH) was used to analyze the data. Effects were analyzed using 2-tailed t tests.

Results

(1) Use of social media at work can improve information support (t₁₄=13.318, P<.001), emotional support (t₁₄=13.184, P<.001), and self-efficacy (t₁₄=6.364, P<.001) for older people; (2) information support is the main factor affecting the self-efficacy of older workers (t₁₄=23.304, P<.001), as compared with emotional support (t₁₄=1.799, P=0.07); (3) the impacts of emotional support on work ability (t₁₄=8.876, P<.001) and work stress (t₁₄=9.545, P<.001) are generally higher than those of information support (t₁₄=4.394, P<.001; t₁₄=5.002, P<.001); (4) self-efficacy has an impact on work ability (t₁₄=5.658, P<.001) and work stress (t₁₄=4.717, P<.001); and (5) the impacts of work ability (t₁₄=8.586, P<.001) and work stress (t₁₄=8.579, P<.001) on retirement willingness are greater than those of emotional support (t₁₄=2.112, P=.04) and information support (t₁₄=4.314, P<.001).

Conclusions

Our study confirms that the use of social media at work has a positive impact on older workers. Based on the findings, we have put forward proposals to extend people’s working lives and help governments implement health bonus policies. In the future, we will compare the different values of willingness to delay retirement among older people in different occupations and different cultures.

The effects of age on response time, accuracy, and shoulder/arm kinematics during hammering

The aim of this study was to investigate the effects of age on response time and accuracy during a hammering task. Older male workers aged 51-69 years (older group: OG, n = 23) and younger male reference individuals aged 25-36 years (younger group: YG, n = 16) performed the experiment. Response time, accuracy, and 3D shoulder/arm kinematics were acquired using motion capture. The effects of age were investigated using linear mixed model analysis. Response times were significantly longer for OG compared with YG (P < 0.001) while no marked differences in the accuracy was observed (P = 0.729). OG showed less hammer displacement and smaller range of motion in the shoulder. Although older workers seemed to use a less biomechanical demanding motor strategy, their response times during hammering were about twice that of younger individuals.

Physical performances show conflicting associations in aged manual workers

Ageing is associated with a decrease in physical performance implying that aged manual workers may be unable to match the physical requirements of their jobs. In this cross-sectional study, 96 male manual workers aged 51–72 years were recruited. Outcomes included handgrip strength (HGS), fat-free mass (FFM), fat percentage, cardiorespiratory fitness (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{{\rm{V}}}$$\end{document}V˙O₂max), forced vital capacity (FVC), forced expiratory volume after 1 s (FEV₁), spinal flexibility, sit-to-stand test performance and static balance. Covariates included height, smoking habits, leisure-time physical activity and systemic inflammation from blood samples. Outcomes were also compared with general populations. Age was negatively related to FFM and FEV₁, whereas static balance (velocity of displacement) was positively associated with age. Greater HGS, but poorer \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{{\rm{V}}}$$\end{document}V˙O₂max and FEV₁/FEV ratio were found compared with general populations. Age was negatively related with physical performances although a large part of the variance in performance could be explained by factors other than age such as smoking and systemic inflammation. The manual workers had greater muscle strength but had poorer cardiorespiratory fitness and lung function when compared with general populations. Specific health interventions targeting specifically cardiorespiratory fitness, lung function, and balance may be needed to maintain physical performances among manual workers.

On the role of ageing and musculoskeletal pain on dynamic balance in manual workers

The purpose of this study was to explore the interacting effects of age and musculoskeletal pain on balance in manual workers. Ninety male manual workers aged 51-72 yr were recruited and stratified according to lower extremity musculoskeletal pain intensity (pain/no pain) and work status (working/retired). The five-repetition sit-to-stand (STS) test was used to assess lower extremity function including completion time, stand time, sit time and dynamic rate of force development both in the upwards (RFD_up) and downwards moving phase (RFD_down). Dynamic balance was expressed as the range, velocity, standard deviation (SD), maximum Lyapunov Exponent and sample entropy of centre of pressure displacement in the anterior-posterior and medial-lateral direction, as well as free moment during the STS test. Except for higher age, no marked differences were seen between working and retired participants. Both age and musculoskeletal pain were negatively associated with motor function. Age × pain interactions showed that completion time, stand time, RFD_up and RFD_down were negatively associated with age for participants without pain, but positively for those with pain. Similar findings were seen for dynamic balance. These findings indicate that the effects of lower extremity musculoskeletal pain on lower extremity function and dynamic balance are age dependent.

Physical-work ability and chronic musculoskeletal complaints are related to leisure-time physical activity: Cross-sectional study among manual workers aged 50–70 years

Aims: To investigate the associations between both high- and low-intensity leisure-time physical activity on physical-work ability and chronic musculoskeletal complaints among manual workers aged 50–70 years. Methods: In this cross-sectional study, 1763 manual workers (mean age 57.1, SD ± 4.7 years) replied to questions about leisure-time physical activity, physical-work ability, chronic musculoskeletal complaints as well as health and lifestyle factors. Ordinal and binomial logistic regression models were constructed to assess the influence of the duration of both low- and high-intensity physical activity on physical-work ability and chronic musculoskeletal complaints, respectively. Models were adjusted for gender, age, smoking, alcohol intake, body mass index, physical-work demand, work experience, chronic disease and, regarding physical-work ability, also for chronic musculoskeletal complaints. Results: A statistically significant association between greater physical-work ability and high-intensity physical activity was found for workers engaged in 3–4 h/wk and ⩾ 5 h/wk (OR 1.59, 95% CI 1.15–2.19 and OR 1.56, 95% CI 1.10–2.22, respectively). For both high- and low-intensity physical activity, a duration of 3–4 h/wk was associated with lower odds of reporting chronic musculoskeletal complaints in the knees (OR 0.65, 95% CI 0.42–1.00 and OR 0.61, 95% CI 0.38–0.99, respectively). Conclusions: Engaging in ⩾ 3 h/wk of high-intensity leisure-time physical activity was associated with greater physical-work ability among manual workers aged 50–70 years. Both high- and low-intensity physical activity related to lower odds of having chronic musculoskeletal complaints in the knees.

The effects of age and musculoskeletal pain on force variability among manual workers

The present study investigated the influence of age and musculoskeletal pain on force variability during a continuous isometric handgrip force task performed at 30% of maximal voluntary contraction carried out until failure. We recruited 96 male manual workers aged 51-72 years. The participants were stratified according to their age (50-59 and 60+ years) and by pain status (no pain, acute pain and chronic pain). The amplitude and structure of variability expressed as respectively standard deviation (SD) and coefficient of variation (CV), and sample entropy (SaEn) were calculated from the endurance task. The oldest group had an approximately 18% longer endurance time than the youngest group. No between-group differences were found in SD or CV, whereas a significant interaction between age and pain stage was found for SaEn. The youngest group showed lower SaEn than the oldest for both those with chronic pain and those without pain, indicating less force complexity, whereas a tendency for the opposite was found in the acute pain group. Within the pain stage groups, workers with acute pain had higher SaEn compared with both the no pain and chronic pain groups. These findings suggest that age and musculoskeletal pain differentially affects the structure of force variability in manual workers.