Effect of different multipliers and their interactions during manual lifting operations

Batish

et al. 2011

Hum Ftrs & Erg Mfg Svc

In the present study, the effect of lifting task parameters on the heart rate and oxygen uptake of workers during manual lifting tasks in different ambient conditions was evaluated. The experiments conducted in two different temperature conditions showed a significantly higher oxygen uptake and heart rate in colder conditions as compared to warmer conditions. Three other factors, namely, load, lifting frequency, and vertical distance were found to significant affect the responses. Various combinations of significant factors were used to calculate oxygen uptake and heart rate. These were then compared with the safe limits as per the maximum aerobic capacity of workers. Based on these comparisons, the safe combinations were identified that can be used to design lifting tasks in varied ambient conditions. The study further concluded that lifting tasks performed in winter should have different relaxation or fatigue allowances built into the cycle time of the task to compensate for higher exertion. © 2011 Wiley Periodicals, Inc.

Section: Literature Reviewsupporting

confidence: 93%

An Experimental Study to Evaluate the Effect of Ambient Temperature during Manual Lifting and Design of Optimal Task Parameters

Batish

et al. 2011

Hum Ftrs & Erg Mfg Svc

“…The interaction effects of the RNLE multipliers were also assessed by a factorial analysis on working heart rates (Maiti & Bagchi, 2006). The overall interaction effect contributed to 10% of the total variance of the normalized working heart rate (Maiti & Bagchi, 2006). The exploratory finding of this study suggests a non-linear nature of interactions of the RNLE multipliers.…”

Section: Resultsmentioning

confidence: 99%

“…The exploratory finding of this study suggests a non-linear nature of interactions of the RNLE multipliers. It is recommended that interaction of some multipliers be included in the RNLE (Maiti & Bagchi, 2006). This recommendation, however, may be premature because heart rate data used in Maiti and Bagchi’s study were not based on MSD risk data.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of the Impact of the Revised National Institute for Occupational Safety and Health Lifting Equation

Lu¹,

Putz-Anderson²,

Garg

et al. 2016

Hum Factors

Objective To evaluate the impact of the revised National Institute for Occupational Safety and Health lifting equation (RNLE). Background The RNLE has been used extensively as a risk assessment method for prevention of low back pain (LBP). However, the impact of the RNLE has not been documented. Methods A systematic review of the literature on the RNLE was conducted. The review consisted of three parts: characterization of the RNLE publications; assessment of the impact of the RNLE; and evaluation of the influences of the RNLE on ergonomic standards. The literature for assessing the impact was categorized into four research areas: methodology, laboratory, field and risk assessment studies using the Lifting Index (LI) or Composite LI (CLI), both of which are the products of the RNLE. Results The impact of the RNLE has been both widespread and influential. We found 24 studies that examined the criteria used to define lifting capacity used by the RNLE, 28 studies that compared risk assessment methods for identifying LBP, 23 studies that found the RNLE useful in identifying the risk of LBP with different work populations, and 13 studies on the relationship between LI/CLI and LBP outcomes. We also found evidence on the adoption of the RNLE as an ergonomic standard for use by various local, state, and international entities. Conclusion The review found 13 studies that link LI/CLI to adverse LBP outcomes. These studies showed a positive relationship between LI/CLI metrics and the severity of LBP outcomes.

“…and Bannag [26], Wu [27], Maiti and Bagchi [28], and Abadi et al [29], that frequency of the lift has a significant effect on the average heart rate values.…”

Section: S79mentioning

confidence: 99%

Effect of task factors on the heart rate recovery time in a lifting task

Aghazadeh¹,

Amini²

2018

OER

BACKGROUND: There is an extensive body of research reviewing the effect of task factors on the Maximum Acceptable Weight of Lift (MAWL) or heart beats elevation as a result of a manual material handling task. However, there are now studies that investigate the effect of task factors on the heart rate recovery time (HRR). OBJECTIVE: The purpose of the study was twofold: (1) to determine the HRR for a series of lifting tasks based on the activity heart rate and by using a set of task variables, (2) to compare the effect of three task factors on the HRR following a lifting task. METHODS: This research was constituted of capturing the duration that heart rate needs to get to a steady state following a lifting task, along with conducting the survey of perceived exertion (Borg). Three independent variables of this study (taskfactors) were weight of the lift (10 and 20 kg), frequency of the lift (6 and 9 lifts per minute), and the duration of the lift (5 and 10 minutes). Given the possible treatment combinations, a total of 8 treatments was obtained. Twenty-four university male students performed the lifting tasks in a between-subject design. Each participant performed one treatment by lifting a box from knuckle to shoulder height at a certain frequency, duration and weight. All eight treatments were equally replicated with three observations per treatment group. RESULTS: Increasing weight and frequency of the lift significantly increased the HRR (respectively by 37% and 34%), while the HRR had a slight decrease when duration was doubled (approximately −2.7%). Weight of the lift was the only factor led to a significant change in the perceived difficulty of the task among participants (approximately 20%). CONCLUSIONS: Among main factors, frequency and weight of the lift had a significant effect on the HRR (p-values < 0.1). Among the interaction effects, the interaction of frequency and duration had a significant effect on the HRR. The only factor that had a significant effect on the Borg-rating was weight of the lift (p-value < 0.1).