1
|
Yi C, Zuo H, Zhao C, Li KW, Hu H, Tang F, Long T. Fatigue and Recovery of Muscles for Pulling Tasks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15159. [PMID: 36429882 PMCID: PMC9690050 DOI: 10.3390/ijerph192215159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Manual materials handling (MMH) contributes to musculoskeletal disorders (MSDs) in the workplace. The development and recovery of muscle fatigue are essential in work/rest arrangements for MMH tasks. A pulling experiment, including a muscle fatigue test and a muscle fatigue recovery test, was conducted. In the muscle fatigue test, the participant performed a pulling task on a treadmill with a walking velocity of 1 km/h until they could no longer do so. The load was either 30 or 45 kg. The maximum endurance time (MET) was recorded. The pull strength (PS) of the participant both before and after the pulling task was measured. The subjective ratings of muscle fatigue after the pulling task were recorded. In the muscle fatigue recovery test, the participant took a rest after performing the pulling task. The participants reported their subjective ratings of muscle fatigue on the CR-10 scale after taking a rest for a time period t, where t = 1, 2,…, 6 min. The PS of the participant was then measured again. It was found that the load significantly affected the MET for pulling tasks. The load was insignificant to the decrease of the PS, but was significant to the decrease rate (PS decrease per min) of the PS. The PS decrease rate for the 45 kg condition (30.8 ± 16.5 N/min) was significantly higher (p < 0.05) than that of the 30 kg condition (15.4 ± 5.5 N/min). The recovery time significantly affected the PS and CR-10. Two MET models were established to explore the development of muscle fatigue in pulling tasks. A PS model was constructed to describe the recovery of muscle force. A CR-10 model was proposed to show the subjective ratings of recovery. These models are beneficial for determining the work/rest allowance for pulling tasks.
Collapse
Affiliation(s)
- Cannan Yi
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
| | - Huali Zuo
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
| | - Caijun Zhao
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
| | - Kai-Way Li
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
- Department of Industrial Management, Chung Hua University, Hsinchu 30012, Taiwan
| | - Hong Hu
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
| | - Fan Tang
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
| | - Tong Long
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang 421102, China
| |
Collapse
|
2
|
Li KW, Li W, Peng L. Effects of handle height and load on the endurance time for simulated demolition tasks. Work 2021; 70:615-624. [PMID: 34657842 DOI: 10.3233/wor-213597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Manual demolition tasks are heavy physical demanding tasks which involve forceful exertion of sustained pushing. They result in muscle fatigue which could lead to musculoskeletal disorders. Assessments of maximum endurance time (MET) are essential in understanding the developing of muscle fatigue for these tasks. OBJECTIVE The objectives of this study were to determine the effects of handle height and load conditions on the MET, and to establish MET models for the simulated demolition tasks. METHODS Twenty three male participants performed simulated demolition tasks under three loads and three handle heights conditions until they could not do so any longer. Their METs and ratings of perceived exertion were recorded and analyzed. RESULTS The results showed that both load and handle height were significant (p < 0.0001) factors affecting the MET. Regression models to predict the MET under handle height and load conditions were established. The mean absolute deviations of these models were between 1.91 and 4.84 min. CONCLUSION The MET models established may be used to estimate the MET which may be adopted in work/rest arrangement for demolition tasks using a handheld demolition hammer.
Collapse
Affiliation(s)
- Kai Way Li
- Department of Industrial Management, Chung Hua University, Hsin-Chu, Taiwan
| | - Wenbao Li
- Engineering Science, Chung Hua University, Hsin-Chu, Taiwan.,School of Sports Training, Jilin Sport University, Changchun, China
| | - Lu Peng
- College of Information Management, Nanjing Agricultural University, Nanjing, China.,Department of Systems Engineering and Engineering Management, City University of Hong Kong, Kowloon, Hong Kong
| |
Collapse
|
3
|
Effects of Lifting Method, Safety Shoe Type, and Lifting Frequency on Maximum Acceptable Weight of Lift, Physiological Responses, and Safety Shoes Discomfort Rating. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17093012. [PMID: 32357502 PMCID: PMC7246667 DOI: 10.3390/ijerph17093012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 11/17/2022]
Abstract
This study aimed to investigate the physical effects of precision lifting tasks on the maximal acceptable weight of a lift (i.e., psychophysiological lifting capacity where the workers adjust the lifting weight in order to work without any fatigue or strain at the end of the work while wearing common safety shoe types). Additionally, the physical difference between the precise and non-precise lifting conditions associated with wearing safety shoes were assessed by respiration responses and shoe discomfort ratings. To achieve the objective of the study, ten healthy male workers were selected by age (between 25 to 35 years old). Their anthropometric characteristics, including knuckle height, knee height, and body mass index (BMI), were measured. A three-way repeated measures design with three independent variables was used; the variables included-the (1) lifting method (precise and non-precise), (2) lifting frequency (1 and 4 lifts per min), and (3) safety shoe type (light-duty, medium-duty, and heavy-duty). The physiological response variables and one of the subjective factors of this study were-(1) respiration responses, and (2) shoe discomfort rating, respectively. The data were analyzed using the Mauchly's test of sphericity, Shapiro-Wilk normality test, and analysis of variance (ANOVA). The results showed that the use of heavy-duty safety shoes typically increased the shoe discomfort rating under precise lifting methods. Additionally, the lifting frequency was determined to be one of the main factors affecting respiratory responses and shoe discomfort rating. This study also found that respiration responses rose on four lifts per min as compared to 1 lift per min, regardless of the lifting method type. This study indicated that the replacement of some types of ordinary safety shoes used in some workplaces with those selected appropriately might significantly reduce the rating effort required to lift objects or tools. However, the benefits should be carefully evaluated before replacing the safety shoes.
Collapse
|
4
|
Li KW, Chu JC, Chen CC. Strength Decrease, Perceived Physical Exertion and Endurance Time for Backpacking Tasks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16071296. [PMID: 30978951 PMCID: PMC6479300 DOI: 10.3390/ijerph16071296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/09/2019] [Accepted: 04/09/2019] [Indexed: 12/21/2022]
Abstract
Manual material handling (MMH) tasks create a burden for workers which could result in musculoskeletal injuries. Assessments of the decrease of muscular strength and the maximum endurance time (MET) for MMH tasks are essential in studying the ergonomic risk of MMH tasks. A backpacking experiment was conducted for measuring the MET for MMH tasks. Human participants carried a load on their back and walked on a treadmill under various load, walking speed, and ramp angle conditions until they coud no longer do so. It was found that the participants were able to walk for approximately 15 min to two hours before they needed to have a pause. Their back and leg strengths declined moderately due to performing the tasks. These tasks resulted in an increase in heart rate and elevated perceived physical exertion. The rating of perceived exertion (RPE)/heart rate ratio in our backpacking tasks was 31% higher than that in the literature, implying the calibration of the RPE may be required for such tasks. A MET model incorporating the fMVC_back, body weight, walking speed, and ramp angle was established. This model may be used to determine the work/rest allowance for backpacking tasks under conditions similar to this study.
Collapse
Affiliation(s)
- Kai Way Li
- Department of Industrial Management, Chung Hua University, Hsinchu 30012, Taiwan.
| | - Jenn Chun Chu
- Ph.D. Program of Technology Management, Chung Hua University, Hsin-Chu 30012, Taiwan.
| | - Ching Chung Chen
- Department of Information Management, Hsing Wu University of Science & Technology, New Taipei 24452, Taiwan.
| |
Collapse
|
5
|
Yi C, Li KW, Tang F, Zuo H, Ma L, Hu H. Pulling strength, muscular fatigue, and prediction of maximum endurance time for simulated pulling tasks. PLoS One 2018; 13:e0207283. [PMID: 30444895 PMCID: PMC6239301 DOI: 10.1371/journal.pone.0207283] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/29/2018] [Indexed: 12/01/2022] Open
Abstract
Truck pulling is one of the common manual materials handling tasks which contribute to musculoskeletal disorders. The maximum endurance time (MET) for two-handed truck pulling tasks has been rarely discussed in the literature. The objectives of this study were to explore the development of muscular fatigue when performing two-handed pulling task and to establish models to predict the MET. A simulated pallet truck pulling experiment was conducted. Sixteen healthy adults including eight females and eight males participated. The participants pulled a handle simulating that of a pallet truck using two hands until they could not pull any longer under two postures. The forces applied for females and males were 139.65 N and 170.03 N, respectively. The maximum voluntary contractions (MVC) of the pulling strength both before and after the simulated pull were measured. After each trial, both the MET and subjective ratings of muscular fatigue on body segments were recorded. The results showed that posture significantly affected MVC of pull both before and after the trial. It was found that foot/shank of the front leg had higher subjective ratings of muscular fatigue than the other body segments. The MET equations employing both power and logarithmic functions were developed to predict the MET of the two-handed pulling tasks. Predictive models established in this study may be used to assess the MET for two-handed pulling tasks.
Collapse
Affiliation(s)
- Cannan Yi
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang City, Hunan Province, China
| | - Kai Way Li
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang City, Hunan Province, China
- Department of Industrial Management, Chung Hua University, Hsin-Chu, Taiwan
- * E-mail:
| | - Fan Tang
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang City, Hunan Province, China
| | - Huali Zuo
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang City, Hunan Province, China
| | - Liang Ma
- Department of Industrial Engineering, Tsinghua University, Beijing, China
| | - Hong Hu
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang City, Hunan Province, China
| |
Collapse
|
6
|
Yi C, Tang F, Peng L, Li KW, Ma L, Hu H. Modeling of maximum endurance time for static pulling tasks. Work 2018; 60:455-463. [PMID: 30040782 DOI: 10.3233/wor-182751] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Pallet truck pulling is one of the common manual materials handling tasks which could result in musculoskeletal injuries. The endurance time for sustained truck pulling tasks has been rarely discussed in the literature. OBJECTIVE The objectives of this study were to measure the muscular fatigue after performing a pulling task and to establish models to predict the maximum endurance time for truck pulling tasks. METHODS A simulated truck pulling experiment was conducted. Ten human participants were recruited. The participants pulled a handle simulating that of a pallet truck under two loading conditions until they could not pull any longer. RESULTS The results indicated that hand/wrist and elbow had higher subjective ratings of muscular fatigue than the other body segments. A subjective rating of 5 or more was found on at least two of the body segments for all trials except one. An exponential model and a power model were established to predict the maximum endurance time of the pulling tasks. CONCLUSION Hand/wrist and elbow were the body segments most likely to suffer muscular fatigue for the simulated truck pulling tasks. The endurance time models established may be adopted in job designs for one-handed truck pulling tasks.
Collapse
Affiliation(s)
- Cannan Yi
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang, Hunan Province, PRC
| | - Fan Tang
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang, Hunan Province, PRC
| | - Lu Peng
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang, Hunan Province, PRC
| | - Kai Way Li
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang, Hunan Province, PRC.,Department of Industrial Management, Chung Hua University, Hsin-Chu, Taiwan
| | - Liang Ma
- Department of Industrial Engineering, Tsinghua University, Beijing, PRC
| | - Hong Hu
- School of Safety & Environmental Engineering, Hunan Institute of Technology, Hengyang, Hunan Province, PRC
| |
Collapse
|