Strength Decrease, Perceived Physical Exertion and Endurance Time for Backpacking Tasks

Li, Kai Way; Chu, Jenn Chun; Chen, Ching Chung

doi:10.3390/ijerph16071296

Cited by 5 publications

(11 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on this polynomial equation, Rohmert et al (1986) has proposed MET models to incorporate five different postures employing power functions. MET models showing similar curvilinear decreasing patterns have been reported (Choi, Lee, Lee, & Kong, 2017; El Ahrache, Imbeau, & Farbos, 2006; Garg, Hegmann, Schwoerer, & Kapellusch, 2002; Li, Chu, & Chen, 2019; Li, Peng, & Yi, 2019; Manenica, 1986; Mathiassen and Åhsberg, 1999; Rose, Ericson, & Ortengren, 2000; Rose, Ericsson, Glimskar, Nordgren, & Ortengren, 1992; Sato, Ohashi, Iwanaga, Yoshitake, & Shimada, 1984; Yi, Li, et al, 2018, Yi, Tang, et al, 2018; Zhang, Li, Zhang, Ma, & Chen, 2014).…”

Section: Introductionsupporting

confidence: 74%

See 1 more Smart Citation

Maximum endurance time modeling for push and pull tasks considering gender and handle height

Liu

2020

Hum Ftrs & Erg Mfg Svc

Self Cite

View full text Add to dashboard Cite

The strengths of both push and pull using both hands at handle heights of 75, 90, and 135 cm were measured for 11 female and 8 male participants. In addition, simulated push and pull tasks were performed on one of the three heights as in the strength measurements. In these tasks, the participants either pushed or pulled a swing suspended with one of the two loads (32.5 and 42.5 kg) until they could no longer do so. Then, the strength of push or pull was measured again. The participants also reported bodily discomfort on their body parts on a CR-10 rating scale. It was found that hands and leading leg had the highest CR-10 scores among the body parts and were the bottleneck body parts for the push and pull tasks, respectively. Models of maximum endurance time incorporating gender and handle height, in addition to force ratio, were developed. These models may be adopted in predicting the endurance time in job design concerning work/rest arrangement.

show abstract

Section: Introductionsupporting

confidence: 74%

“…Yi, Li, et al (2018) and Yi, Tang, et al (2018) have developed MET models to fit the data for truck pulling tasks. Li, Chu, et al (2019) proposed models to predict the MET for backpacking tasks. Some of the subject‐specific MET models may also be regarded as task‐specific.…”

Section: Introductionmentioning

confidence: 99%

Maximum endurance time modeling for push and pull tasks considering gender and handle height

Liu

2020

Hum Ftrs & Erg Mfg Svc

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the muscle fatigue test, the participant pulled and walked on a treadmill at a velocity of 1 km/h (see Figure 1 ) until he could not continue any longer. The walking speed was determined following the recommendations in the literature [ 6 , 43 , 44 , 45 , 46 ] and the results of our pilot trials. Both the MET and PS before and after the test were recorded.…”

Section: Methodsmentioning

confidence: 99%

Fatigue and Recovery of Muscles for Pulling Tasks

Zuo

Zhao

et al. 2022

IJERPH

View full text Add to dashboard Cite

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.

show abstract

“…Typically, children may choose a two-strap BP, one-strap BP, suitcase, satchel or schoolbag with wheels. The type of school bag influences their pain occurrence, discomfort, posture disorders and ergonomics of movement [ 17 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, an analysis of the impact of school BPs should be carried out in dynamic conditions. During dynamic activities, such as running, the momentum of the head and torso mass increases [ 8 , 9 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

Influence of School Backpack Load as a Variable Affecting Gait Kinematics among Seven-Year-Old Children

Tomal

Fryzowicz²,

Skorupska

et al. 2022

IJERPH

View full text Add to dashboard Cite

This article investigates schoolchildren’s ability to carry an additional load using a backpack (BP). According to scientific research, there is no precise limit to the maximum backpack load, which varies from 10% to 15% of body weight (BW). The purpose of this study was, therefore, to evaluate the influence of an additional external load carried using a backpack on gait kinematics among seven-year-old children in Poland, including assessment of the gender differences. The study was conducted among 26 (13 boys and 13 girls) primary school children aged seven years. The children walked at their preferred speed, under four conditions: with no load (0% BW) and with 10%, 15% and 20% BW. Spatiotemporal parameters were measured using the 2 m Footscan® platform system and photocell Sectro timing system. The children walked more slowly under an additional load. Their step length and single support time decreased. Their base of support, step time and double support time increased. There was no significant effect on their stride length or gait cycle time. The gait kinematic changes were most evident between 10% BW and greater loading. The results highlight how children’s gait is affected by carrying additional external loads, which should not exceed 10% BW. That limit is appropriate for both genders.

show abstract

Strength Decrease, Perceived Physical Exertion and Endurance Time for Backpacking Tasks

Cited by 5 publications

References 46 publications

Maximum endurance time modeling for push and pull tasks considering gender and handle height

Maximum endurance time modeling for push and pull tasks considering gender and handle height

Fatigue and Recovery of Muscles for Pulling Tasks

Influence of School Backpack Load as a Variable Affecting Gait Kinematics among Seven-Year-Old Children

Contact Info

Product

Resources

About