*Associat Proessor in Aligarh Muslim University, Aligarh, India; Professor in Lakshmi Mittal Institute of Management, New Delhi, India.
51
Evaluation of Ergonomic Aspects of Meal Trolleys in Jazan Region Hospitals to Ameliorate Musculoskeletal Disorder
Asif Haleem*
Industrial Engineering Department, College of Engineering, Jazan University, Jizan, Kingdom of Saudi Arabia
Abstract. In hospitals trolleys are used for carrying meals, medicines and other deliveries to the in-patients who are hospitalized.
Normally, the trolleys are ordered and purchased from vendors who have little knowledge about ergonomic principles. Many a time even manufacturers of trolleys and other medical equipment may not have used ergonomic guidelines strictly to ensure quality product conforming to the best cart dimensions thus increasing the risk of MSD among the meal trolley users. The present research pertains to conduct of ergonomic evaluation of the meal trolleys currently being used in Jazan region hospitals in the Kingdom of Saudi Arabia. Ten hospitals were chosen with each having over 100 beds in inpatient ward; each had an emergency ward and outpatient department (OPD) ward; and each had specialists and consultant doctors. Out of 85 respondents who participated in the study, 60 responded within the time frame. This sample consisted of 35 expats from India and Philippines, and 25 Saudi nationals. A questionnaire based on ergonomic requirements was administered, reinforced with an interview, to the sample to elicit their response on two major factors: Operational survey and biomechanical survey. The former was to enquire what they felt about the operational aspect of using the trolley, and the latter was to determine what physical pain, if any, the present design caused to different parts of the body. The responses from the questionnaires showed that some design aspects of the existing hospital meal trolleys need to be looked for improvement to reduce MSDs, viz. the position of the handle was of concern to the users, hence the need for repositioning the handle to accommodate both 5% tile users and 95% tile users; and incorporating the braking system in order to ease the halting of the trolley in case of emergency and to reduce the force required to bring the trolley to stop.
Keywords: Hospital meal trolley, Ergonomics evaluation, Hospital equipment design, Push–pull forces, Ergonomic design, Ergonomic principles, anthropometry.
1. Introduction
Workers are involved in many material handling activities in both industrial and service sector. In hospital and hospitality services, carts and trolleys are extensively used for carrying and delivering food and medicines to patients to all floors of the hospital. Moved manually over floors and vertically using elevators, these trolleys are normally operated by workers designated for this job. Moving trolleys involves pushing and pulling forces. Bending and lifting are also required in handling the meal trays. These postures and other factors give rise to disorders and injury to some parts of the body
resulting in temporary and permanent damage to musculature. Studies carried out in the 80’s and 90’s of the last century on such vehicles showed that they caused suffering to workers because of their misuse or due to poor designing of such vehicles. Hence, use of such vehicles led to injuries in the short run; and to pain and MSDs in the long run. Major injuries resulting from pushing and pulling trolleys and carts in food and drink industries may be summarized in three types, being strains, sprains, and bruises [1]. MSDs include these as temporary and permanent forms of ill health associated with parts of the body where there is a connection of motor nerves with muscles,
tendons, the skeleton, cartilage, and ligaments
[2]. It was also observed by [2] that weariness also leds to fatigue during shift period thereby affecting the temperament of workers that is ultimately transferred on to the patients within their care. From the above study it is obvious that parts of the body most likely affected are pain in upper and lower back, aching arms, shoulders, thighs, legs, … etc.
Factors that affect the design of trolleys and their smooth functioning are listed in Fig.
1. The usability of trolleys is measured by ease of use by hospital staff and nurses. Usability is essentially a composition of physical and perceptual stresses, efficiency of vehicle movement, its maneuverability, and safety of employees. The factors that impact usability may be categorized into four groups such as:
Task, design, environment, and user. However since this study is confined to hospital trolleys only and pertains to identification of defects in some design factors of the trolley that cause disorders and pain to operators of trolleys used in Jazan hospitals, only two factors were explored for application of ergonomics to the manual trolleys. These factors were Operational factor and Discomfortal factor.
Operational factor refers to the anthropometry of the users, and the designing of trolleys to accommodate 5 percentile and 95 percentile (Note: In this context, 5% tile represents a size where only 5% of the population is smaller;
95% tile represents a size where 5% are larger). Lin et al. (2006) [3] reported that manual material handling (MMH) especially involving lifting is a major safety and health risk in places like hospitals, etc. MSDs often happen due to overstraining of the body when the operator is required to meet the demand of MMH tasks. Findings of a recent study by Huei et al. (2015) [4] suggest that nursing staff should adopt forward pushing when moving a nursing cart, instead of backward pulling, and that uphill paths should be avoided in the
design of work environments. In terms of distribution of the load in a nursing cart, heavier materials should be positioned at bottom of the cabinet, centered on the horizontal plane and close to the handle, to reduce the physical load of the nursing staff.
All the more reason to make use of ergonomic and anthropometric principles in the design and evaluation of human work vis-à-vis hospital trolleys to ameliorate the occurrence of work related MSD injuries.
Since ergonomics or human factors engineering is applied in job designing, it helps in preventing or minimizing MSDs caused by job tasks involving pushing and pulling of trolleys/carts, or involving use of bending and lifting postures [7]. According to
[8], “considering anthropometric data in the design and construction of hospital meal trolleys/carts will go a long way in reducing the stress on both health workers and patients inclusive”. The problem involving pushing and pulling is so acute that Health and Safety Executive (HSE) provided the following statistics to emphasize the importance of applying ergonomics to job design so as to ameliorate pain and disorders. HSE pointed out “the most frequently reported site of injury was the back (44%), followed by the upper limbs (Shoulder, arms, wrist and hand) accounted for 28.6%, 12% more accidents involved pulling than pushing, 61% of accidents involved pushing and pulling objects that were not supported on wheels (bales, desks, … etc.), 35% of pushing and pulling accidents involved objects [9, 10]. Thus statistics shows that there is a case for eliminating or reducing the risk factor associated with pulling and pushing. In the use of hospital meal trolley/cart, [8] lay stress on “the posture of the operator in relation to the lengths of appropriate body segments, body position and the layout of the various components of the equipment, the interference of the equipment
elements with body segments and the visual requirements of the work that dictate the posture”.
In Saudi Arabia, no study has been conducted till date to evaluate the design and operation of a hospital meal trolley from an ergonomics viewpoint. Consequently, no published information is available in this country. Therefore, the goal of the present paper is to explore and examine the use of ergonomics to the operation of hospital meal
trolleys, that are in use in this part of the country (Jazan province), and their relationship with MSDs in order to minimize discomfort and risk of injury to the employees and nurses carrying out the operations. The second objective pertains to recommending modifications to the existing hospital meal trolley are being used in Jazan region hospitals based on ergonomic/anthropometric principles and data.
Fig.1. Factors and usability of manual vehicles (developed from Ref. [5,6]).
2. Methodology
2.1 Identifying the Ergonomic Problems of the Hospital Meal Trolleys
Questionnaire (see appendices)
Several factors affecting the use of the hospital meal trolleys such as maneuverability, strength required in operating them and other factors were considered and grouped into two major sections [8] and [11]. A structured questionnaire (see appendices) comprising these two sections (Operation section and Discomfort section) was used [11,12]. Reliability
and validity were assumed as conforming to the reliability and validity of earlier experiments of Ref. [8,11,12].
Through responses and interviews with experienced nurses and operators, relevant information on task performance, equipment and working posture was obtained.
Mention should be made here that only 4-wheeled trolleys were studied, and that the assumption was that all aisles were in a straight line with no slopes and curbs. Further, other factors that could improve the trolley design, but not considered in this study,
included use of larger wheels, swiveling wheels, trolleys having more than two handles vertically placed, load weight on trolleys, use of motion phases, frequency of use, two workers handling the trolley, types of floors giving rise to friction between shoes and floor and between wheel and floor, maintenance problems, and gender differences in strength and physiological demand.
The first category (operational) had eleven statements requesting the subjects to respond to the questions asking them to evaluate the operation of the trolley to indicate any discomfort they felt in using the meal trolley, as well as the overall rating of the job, each operator is engaged in during his/her shift. This will likely bring forth the design aspects of the trolley that need improvement, and the overall rating of their work.
Operation Section
Factors associated with the operation of the trolley are the design factors and it includes:
i. The task of getting the trolley into motion
ii. The task of turning the trolley while in motion
iii. The task of seeing over the trolley iv. The task of stopping the trolley while in motion
Discomfort Section
The second category will help in the ergonomic evaluation of the trolley. It showed a labeled skeleton asking respondents how much pain, if any, they felt on different parts of the body. It considers all of the parts of the body involved in the operation of the trolleys.
They include the following: neck; shoulder;
arm; elbow; fore arm; buttocks; wrist; hand;
fingers; thigh; knee; leg; foot; upper back;
lower back; and waist.
2.2 Hospital Meal Trolley Evaluation
Figures 2 and 3 show the picture of the evaluated hospital meal trolley common to Jazan hospitals.
The trolley shown in Fig. 2 has a round handle of 3 cm diameter almost at the same height as the tabletop. Tabletop height is not adjustable. Maneuverability is done by a bar.
Fig. 2. Picture of Meal Trolley common to Jazan Hospitals.
Height: 81 cm; Length: 72 cm: Width: 44 cm
Fig. 3. Picture of Meal Trolley common to Hospitals in other regions of Jazan.
The trolley in Fig. 3 has the same height as the one in Fig. 2 and is not adjustable. It has about 3 cm diameter handle as seen in the picture at a height of around 5 cm. Turning to either direction is done by the handle
Analysis of the Questionnaire
The following steps were taken in analyzing the questionnaire:
i. Questionnaire Coding: Values were attached to each of the expected answers the respondent picked from. Such as:
No difficulty = 0,
Slight difficulty = 1,
Moderate difficulty = 2,
Great difficulty = 3,
Extreme difficulty = 4.
Thus the reported mean score ranges from 0 (no difficulty/ no problem) to (1 and 2;
slight or moderate difficulty/ minor or moderate problem) to (3 and 4; great or extreme difficulty/major problem).
ii. Key in of data:
o The values from the coding were statistically analyzed using statistical package for the social sciences (SPSS version 22).
iii. Analysis: SPSS was then used to analyze the coded questions. The responses obtained from ergonomic evaluation of the hospital meal trolleys were also analyzed using SPSS to obtain the non-parametric Chi-Square test as well as the median and interquartile range, the results are presented in Table 1;
Tables 2 and 3
3. Data Collection and Analysis 3.1 Hospital Operator Survey
Sampling of Hospitals
Jazan Region has a number of general and specialty hospitals run by the government, and several private hospitals and private large- sized medical clinics. Out of the entire lot of hospitals in the region only those were sampled that provided full medical treatment and that had a sizable city population. Ten hospitals were chosen with each having over 100 beds in inpatient ward; each had an emergency ward and outpatient department (OPD) ward; and each had specialists and consultant doctors. Hospitals were normally
crowded and the health workers in each of these hospitals were kept extremely busy.
Sampling of Subjects
From the entire population of hospital staff of the ten hospitals in Jazan Region a biased sample of 85 respondents, who attended to the task of the delivery of food and medicines on the trolley to the patients, were selected for the study. The prepared questionnaire was administered to the selected respondents. A total of 60 responses were received within the time frame. This sample consisted of 35 expats (five Philippine female nurses, ten Indian female nurses, and twenty Indian male operators); and 25 Saudi nationals (nine female nurses and sixteen male operators). It is important to note that within 5 years the health sector (excluding specialist doctors) is bound to undergo changes in personnel with 100% Saudi health workers replacing expatriates.
The mean age of the participants (male and female) was 33.9 (SD 7.71) years, ranging from 22 to 36 years. The average number of working hours was 8.4 (SD 1.1) per day. Table 1 gives the average stature height and elbow height of all the participants in the sample.
Table 1. Average and Standard Deviation of Stature Height of all Nurses in cm.
Nationality Male Female
Average S.D. Average S.D.
Saudi 176 2.4 160 2.0
Indian 178 3.0 163 2.5
Philippine Not employed
Nil 155 1.5
Other countries
Not employed
Nil Not employed
Nil
3.2 Problem Constraints
(i) It was difficult to find easy access to hospital premises. Permission was not granted by hospital administration to befriend any worker on the hospital premises. Students had to meet their contacts outside the premises.
(ii) It was difficult to approach female nurses and health staff. In these circumstances help was sought from expatriate doctors and other expatriate staff to obtain appropriate contact. The students established contact through their sisters/female acquaintances.
(iii) Several hospitals abound in the region but much time was spent to find the sample engaged in the delivery of meals and medicines to the patients. Hospital administration could have provided data yet language problem and organizational setup were
barriers in the smooth flow of information.
(iv) There were both Saudi and expatriate workers. Hence Arabic language and English language questionnaires were used.
Responses obtained were translated and may have brought in certain inconsistencies.
(v) In the absence of any anthropometric data of Saudi nationals/expats except height it was difficult to completely apply ergonomics principles. However, the assumption is that all persons selected for the task (and are participating in the project) are normal in nature, i.e. everyone has proportionate limb and body size.
(vi) Finally, before the start of the project every effort was made to train the members of the team in the standard methods of data collection, how to interact with the respondents, and how to focus on the task they had been assigned. This enhanced reliability of the project. However, performance and accuracy variability among members might have added some inconsistency.
4. Result and Discussion 4.1 Results of the Operational Responses
Tables 2 – 4 show the result of the SPSS analysis of the responses obtained from the operational and Discomfort survey questionnaire used to carry out ergonomic evaluation of the hospital meal trolley. The
tables show the median score, the interquartile range and the p-value obtained from the Chi- Square analysis.
The level of perceived stress associated with job factors are reported in Table 2. Median and IQR have been used instead of Mean and SD since the data of the sample is skewed making median as the better form of central tendency measure; using IQR in place of SD as a better option since dispersion values are widely spread.
Among the eleven job factors,
“Overall workload at the end of the shift” had a median value of 3.000 reflecting the users describing the work as hard appeared to be the most difficult work-related activity.
“Handle height (pulling)” and
“Handle height (pushing) with median values as 3.000 and 2.000, respectively, show that the placement of handle is a cause for worry.
The median score for the “Force used to stop the trolley” was 2.000, which reflect that the users had concern for the high force needed to bring the trolley to stop.
Significant number of respondents also showed concern for the factor “Parking brake necessary” with a median score of 2.000.
“Need for emergency brake” having a median of 1.000 represents agreement of respondents to a minor difficulty or a moderate problem. They felt the need for emergency brake.
Significantly large number of trolley users felt that there was no difficulty/no problem with remaining factors that yielded median score of 0.000 like “Getting the four wheel trolley into motion”; “Turning the four wheel trolley”; and “Seeing over the four wheel trolley”. Hence these factors were of no concern to the users.
The Chi-Square test (Table 2) revealed that there was a significant difference when p< 0.050 in the responses of the users in the design factors.
4.2 Results of the Discomfort Survey Responses Tables 3 and 4 show the result of the SPSS analysis of the responses obtained from the Discomfort survey questionnaire used to carry out ergonomic evaluation of the hospital meal trolley (see Fig. 4). These tables give the discomfort scores and Chi-Square test values for the body parts (median score, the interquartile range and the p-value obtained from the Chi-Square analysis).
The effect of these design factors can be seen on the feelings felt by the users in the different regions of the body (Tables 3 and 4).
The median score for feeling on the upper back (left and right side), left upper arm, and right shoulder was 2.000 revealing the pain or soreness on those regions of the body, and the Chi-Square test value showed that there were significant differences (p<
0.050) in the response of the users to the level of discomfort experienced. This shows that there is a need for improving trolley design in order to remove or minimize pain in the above-mentioned parts of the body.
The median score for feeling on the left shoulder, left mid-to-lower back, left forearm, right mid-to-lower back, right forearm, left wrist, right wrist was 1.000 (Table 3) reflecting slight pain or soreness, the Chi-Square test also reveals significant differences. Consequently, there is a need for trolley design improvement.
The right forearm has a median score of 1.500 (Table 3) reflecting a range between the feeling of slight pain or soreness and the feeling of pain or soreness, the Chi-Square value revealed significant difference. The same conclusion can be drawn.
Table 2. The level of perceived stress associated with design and job factors (N=60).
S/N Design and Job Factors Median score (0-4)
IQR No
problem (0)
Moderate problem (1-2)
Major problem (3-4)
Chi-Square test:
p-value 1 Getting the four wheel
Trolley into Motion
0.000 0.000 45 8 7 0.0903
2 Turning the four wheel Trolley
0.000 0.000 46 11 3 0.39
3 Seeing over the Trolley 0.000 0.000 48 5 7 0.26
4 Placing and removing the trays
0.000 0.000 55 5 0 0.29
5 Opening and closing the doors
0.000 0.000 56 3 1 0.32
6 Handle Height (Pushing) 2.000 2.000 18 20 22 0.000
7 Handle height (Pulling) 3.000 3.000 8 11 41 0.000
8 Force used to bring four- wheel cart in motion to a stop
2.000 2.000 23 19 18 0.033
9 Need for Emergency Brake
1.000 1.000 30 19 11 0.001
10 A parking brake on the wheels would be useful
2.000 2.000 25 16 19 0.021
11 Overall Work Load At the end of the Shift
3.000 3.000 6 15 39 0.090
Note: There is significant difference when p< 0.050.
Table 3. Prevalence of self-reported musculoskeletal symptoms or discomfort scale scores on both sides of body parts among health workers as a result of the use of hospital meal trolley and Chi-Square test for response to the body region (N=60).
S/
N
Body Region
Left Right
Median IQR Chi- Square Test: p- value. NP 0 Mo/P 1-2 Ma/P 3-4 Median IQR Chi- Square Test: p- value. NP 0 Mo/P 1-2 Ma/P 3-4
1 Shoulder 1.000 1.000 0.000 28 24 8 2.000 2.000 0.014 20 32 8
2 Upper Arm
2.000 2.000 0.000 18 33 10 1.500 1.500 0.014 23 30 7
3 Elbow 1.000 1.000 0.070 26 25 9 1.000 1.000 0.127 25 25 10
4 Fore-arm 1.000 1.000 0.034 27 24 9 1.000 1.000 0.04 26 24 8
5 Wrist 1.000 1.000 0.000 27 23 10 1.000 1.000 0.012 26 25 9
6 Hand 0.000 0.000 0.777 48 6 6 0.000 0.000 0.573 47 5 7
7 Fingers 1.000 1.000 0.158 27 24 7 1.000 1.000 0.259 27 24 7
8 Thigh 1.000 1.000 0.001 26 26 8 1.000 1.000 0.002 27 25 8
9 Knee 1.000 1.000 0.259 28 25 7 1.000 1.000 0.156 28 27 5
10 Lower Leg
1.000 1.000 0.001 28 26 6 1.000 1.000 0.000 27 26 7
11 Ankle/
Foot
0.000 0.000 0.778 50 5 5 1.000 1.000 0.572 49 5 6
Table 4. Prevalence of self-reported musculoskeletal symptoms or discomfort scale scores of centrally placed body parts among health workers as a result of the use of hospital meal trolley and Chi-Square test for response to the body region (N=60).
S/N Parts of Body
Median score (0-4)
IQR No
problem (0)
Moderate problem (1-2)
Major problem (3-4)
Chi-Square test:
p-value
1 Neck 1.000 1.000 27 24 9 0.022
2 Upper Back 2.000 2.000 18 34 8 0.007
3 Lower Back 0.000 0.000 48 5 7 0.011
4 Buttocks 1.000 1.000 28 23 9 0.256
Note: There is significant difference when p< 0.050
The feelings on the left wrist, right wrist, left thigh, right thigh, left lower leg, and right lower leg show that the Chi-Square value of the responses (Table 3) of users had significant difference as also to the level of discomfort experienced during the use of the existing hospital meal trolley. Thus, all the above findings show that the design of the hospital meal trolley needs improvement.
The feelings on the remaining body regions reveal no significant difference in the responses of the users to the level of discomfort experienced during the use of the existing hospital meal trolley.
4.3 Discussion
In the discussion of the results, it is observed that most of the sampled health workers and nurses were either Saudis or Indians (hailing from the Kerala state in India).
From the data on height of participants (Table 1), almost all males (Saudi and Indian) and females were of normal height. In contrast, nurses (female and from Philippines) were of short stature. This could be one reason that the natives of this country did not seem to have any muscular pain due to the trolley dimensions/design. No anthropometric data is available to support this claim except observation. However, they did have a problem seeing over the trolley. Hence it cannot be assumed that short stature gives no discomfort. Maybe, an optimal height of
operator and trolley/handle can be found in later research.
Under ideal environmental conditions, design and task factors contribute more to the usability of manual vehicles than user factors
[13]. In other words, it has been consistently verified that the presence of slopes, stairs, curbs, obstacles, rough or slippery floors, and poor maintenance significantly increase the physical stress on operators. Wheel size and load weight are important factors for all vehicle types but operators complain more about handles that cause serious stress on their arms [14].
The working height is of critical importance in the design of trolley. A suitable working height will allow a posture that will give a comfortable operation of the task ahead and reduce MSDs. The positioning of the handle against which one pushes and pulls is of great concern in our findings. It was apparent that the height of the handle of the meal trolley had to be raised above 86 (81+5) cm. Most of the female nurses having height between (Mean ± 3SD = 155 ± 3×1.50) 150.5 cm and 159.5 cm did not have any bodily ache. In other words, with table top height of 81 cm, handle height of 5 cm, females with height of between 150 and 160 cm did not exhibit discomfort. But workers (particularly males) had a maximum height of (Mean + 3 SD = 178 + 3×3.0) 187 cm and unnatural posture because of low tabletop or low handle.
To accommodate male and female workers within 95% and 5% confidence levels the heights would be (Mean ± 2 SD) at both ends.
The new heights of the workers are 182 cm (upper) and 152 cm (lower). Since it is found that a worker height of 152 is in the comfort zone, the study should establish a higher height limit of tabletop or handle, above 86 cm for the worker stature height of around 180 cm. Hence an upper height of tabletop or handle should be established to around (81+5 +20) 106 cm. Either the tabletop is moved between 81 and 100 cm, or handle is moved up from 86 cm to 106 cm. Therefore, the evaluated hospital meal trolleys in Jazan region could have a design incorporating height adjustment of trolley tabletop/handle from 86 to 106 cm to accommodate workers between 5% and 95% confidence limits, assuming other factors constant. In evaluating trolley design, we find that Jazan hospitals should construct straight aisles with very few turnings, for forward and backward movement to reduce resistant forces (of pushing and pulling) that cause discomfort problems.
Height of handles of our finding is supported by [15] who are of the view that the optimal vertical height for a handle should be about 91–114 cm (i.e., about hip height for males) above the floor to avoid pain and fatigue.
Our finding on force capability is in line with the findings of [16]. He suggested that MSDs can be lowered despite a larger force capability in pushing and pulling when the hands were at hip height than when raised to shoulder or above. This is further confirmed in a study [16] that the pushing force capabilities were greatest at 95 cm vertical height for males and at 89 cm height for females. On the contrary, they found the pulling force capabilities decreased with increased vertical height. Snook and Ciriello (1991) [17] opined that the optimal pull forces exerted by males
and females were at 64 and 57 cm vertical height. Furthermore, the initial and sustained pushing capabilities decreased with distance.
Our present study did not include the amount of distance travelled at one time. The present suggestion for straight aisles are also in agreement with that of De Looze et al. (2000)
[18], who suggested placing the trolley in front of the operator and pushing them forward in a straight line with both hands resulting in the least physical stress and hence reduction of pain in the body parts of the operator.
5. Conclusion
Based on the result obtained from the ergonomic evaluation of the hospital trolleys the following conclusions can be drawn:
The position of the handle was of concern to the users which resulted into discomfort especially on the shoulder and upper back hence there is a need for repositioning to accommodate both 5% tile users and 95% tile users.
The force required to bring the trolley to stop is considered high for most users, which also contribute to the feeling of discomfort on the upper arm and forearm and this contributed to the quest of the users for a braking system in order to ease the halting of the trolley in case of emergency and to reduce the force required to bring the trolley to stop.
It is important to note that this study was made on hospital meal trolleys in the Jazan region hospitals. It could be extended to other regions of the Kingdom. Future studies may include several other factors, which have been assumed in the present study. It is also possible that some of the constraints mentioned in this study viz. anthropometric study of Saudi adults; access to hospital premises, … etc. may be possible in other regions of the Kingdom. Moreover, there is ample scope for the application of ergonomics
tohospitals,healthcare,hospital administration, and hospitality management.
6. Recommendations
Designing of trolleys for hospital considers the mutual effects of anthropometry and location of the equipment elements on various design factors like posture, forces, reach, vision, clearance, and interference of the body segments with the equipment elements during work or task performance. A trolley that is lighter and easier to maneuver would help to reduce risk of injury from pushing it or bringing it to stop. Hospital trolleys should be 120 cm × 80 cm × 144 cm.
Das et al. (2002)[8] due to their light duty.
Some of the changes that might be incorporated in the trolley design to improve the trolley and thus help ameliorate MSDs may include:
Well-designed casters and larger wheels may also increase maneuvering ability and safety.
Two swivel wheels (rear) and two fixed wheels (front), instead of the current four swivel wheels, would improve maneuverability and reduce the twisting forces required to steer [19].
Sealed pre-lubricated precision ball bearings are recommended for hand-push trolleys
A further improvement can be brought about by replacing the bottom sheet of metal with strong wire mesh to reduce the entire weight of the trolley.
A handbrake on the back of the trolley would decrease the effort required to control the speed of the trolley when going down the ramp.
Job rotation will most likely help to reduce cumulative strain for individual workers.
Maintenance: Manual vehicles should be regularly maintained and it is good to designate a maintenance staff [20,21].
Design of hospital meal trolley should be such as to provide a comfortable (erect/slump) posture while moving the trolley.
Design should include vision over the trolley to enable the operator to see in front of the trolley to minimize traffic hazards. In conjunction with a comfortable erect/slump posture, a trolley handle height of about 5 cm below elbow height (approximately hip height) would allow satisfactory push force to move the trolley and facilitate vision above the trolley. However, Hoozemans et al. (2004)[22]
recommends using both hands at shoulder height to facilitate pushing the trolley to reduce back problem. In such a case, vision above the trolley is not a necessity.
Finally, in keeping in line with the above observations, adjust the height of trolley from 86 to 106 cm to be compatible with employee height; width to be kept from 41 to 43 cm; and length 87 to 95 cm adjustable.
Acknowledgement
The author is grateful to the Dean, College of Engineering and the Coordinator, Industrial Engineering Department for their support and motivation in the conduct of the project. He is indebted to the team of researchers who helped him in carrying out the survey and in the collection of data. He also expresses his thanks and appreciation to the various friends and doctors in the hospitals for providing help. He is indebted to the nurses and hospital employees who took participated in the study, without whom the project could not have been completed. No funding was required and none was forthcoming from any quarters, nor was ever asked for.
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[13] Van der Beek, A.J., Kluver, B.D.R., Frings-Dresen, M.H.W. and Hoozemans, M.J.M. (2000), Gender differences in exerted forces and physiological load during pushing and pulling of wheeled cages by postal workers. Ergonomics, 42: 269-281.
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167–174.
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Appendices Hospital Four Wheel Cart Ergonomic Survey Questionnaire
The following questions have been developed to evaluate a number of factors associated with four-wheel hospital meal cart.
1. Biodata
i. Name (Optional):
ii. Age:
iii. Average Height:
iv. Work Section:
v. How long have you being doing this work 2. Operational Survey
The following questions have been developed to evaluate a number of factors associated with your four- wheel hospital carts. We would ask you to take a few moments and complete the questionnaire near the end of the work shift. For each question please chose the option which most closely represents your opinion about the factor under review. The results of this questionnaire will be kept confidential.
Kindly Tick As Appropriate
Getting the four wheel cart in motion, I have:
No difficulty;
Slight difficulty;
Moderate difficulty;
Great difficulty;
Extreme difficulty
ii. Turning the four – wheel cart, I have:
No difficulty;
Slight difficulty;
Moderate difficulty;
Great difficulty;
Extreme difficulty
iii. Seeing over the four-wheel cart, I have:
No difficulty;
Slight difficulty;
Moderate difficulty;
Great difficulty;
Extreme difficulty
iv. Placing and removing the trays, I have:
No difficulty;
Slight difficulty;
Moderate difficulty;
Great difficulty;
Extreme difficulty
v. Opening and closing the doors, I have:
No difficulty;
Slight difficulty;
Moderate difficulty;
Great difficulty;
Extreme difficulty
vi. When pushing the four-wheel cart, the handle height is:
Too Low;
Low;
Moderate;
High;
Too High
vii. When pulling the four-wheel cart, the handle height is:
Too Low;
Low;
Moderate;
High;
Too High
viii. When the four-wheel cart in motion, the force that I use to bring it to a stop is:
Too Low;
Low;
Moderate;
High;
Too High
ix. An emergency brake for the Panic stop would be useful:
o Strongly Agree;
o Agree o Neutral;
o Disagree;
o Strongly Disagree
x. A parking brake on the wheels would be useful:
o Strongly Agree;
o Agree o Neutral;
o Disagree;
o Strongly Disagree
xi. I find my workload for the day:
o Very Hard o Hard o Normal o Easy o Very Easy 3. Discomfort Survey
The folling figure gives anatomy of a human.
Anatomy of a human.
ةقطنم تايفشتسم يف ةمدختسملا ماعطلا تابرع مييقتل ةيرشبلا لماوعلا ئدابم قيبطت يمكييلا يمضعلا زايجلا بارطضا نم دحمل نازاج
ميلح فصاع
يدوعسلا ةيبرعلا ةكممملا ،نازاج ةعماج ،ةسدنيلا ةيمك ،ةيعانصلا ةسدنيلا مسق ة
صمختسملا .
برع تايفشتسملا يف مدختست اذيب موقي .ميترسأ يف نيمونملا ىضرملا ىلإ ىرخأ ضارغأو ةيودلأاو ماعطلا تابجو لقنل تا
تابرعلا هذى ديروت متيو .ةنواعملا تامدخلا لامعو ضيرمتلا دارفأ لمعلا قيرط نع
فرعملا مييدل سيل نيدروم ة
ةسدنى ئدابمب ةيفاكلا
لا نايحلأا نم ريثك يف لب ،ةيرشبلا لماوعلا صملا مزتمي
ئدابملا كمتب نوعن امامت
رطاخم دادزت يلاتلابو ،ميتاجتنم ةدوج ديكوتل
مييقت ءارجإب ثحبلا اذى طبتري .تابرعلا هذى يمدختسمل يمكييلا يمضعلا زايجلا بارطضا –
لمعلا ةئيب ةسدنى قفو –
ماعطلا تابرعل
مت ثيح ،ةيدوعسلا ةيبرعلا ةكممملاب نازاج ةقطنم تايفشتسمب ةمدختسملا ت
اخم ةئام نع اينم لك ةعس ديزت تايفشتسم رشع ةبط
،ميونتمل ريرس و
هذى رداوك نم باجتسا .نييراشتسلااو نييئاصخلأا ءابطلأاب ةموعدم ةيجراخ تادايعو ئراوطمل تادايع اينم لك مضي
ةنيعلا 58 مينم ةدرفم 06
ينمزلا راطلإا للاخ اوباجتسا
، مينم 58 و نيبيمفلاو دنيلا نم ةدفاو ةلامع 58
دقو .ةينطو ةيدوعس ةلامع
ةريبك ةنيع ىمع تعزو ،لمعلا ةئيب ةسدنى ئدابم قفو ةممصم ةنابتسا تمدختسا
، معدو ت ميتارايتخا ةفرعمل ،ةيصخشلا تلاباقملا اي
نمض ،ملاعتسلاا وجوأ نم نيتعومجم و
تابرعمل ليغشتلاو مادختسلاا لماوع ةبسانم ىدم نع ملاعتسلااب ىلولأا ةعومجملا متيت
ملا دوجو .ة هذى مادختسا نع ةسوسحم ملاآ دوجو ىدمب ةمصلا تاذ ةيكيناكيملا ةيويحلا لماوعلا نع ملاعتسلااب ةيناثلا ةعومجملا متيتو
تابرعلا و ، لماوع ضعب دوجو نع ةنابتسلاا هذى تاباجتسا ليمحت جئاتن ترفسأ .اىدوجو لاح مسجلا يف ملالآا هذى عقاومو تايعون
تابرعب ةصاخلا ميمصتلا نيسحت ىلإ جاتحت يتلا تايفشتسملاب ةمدختسملا ماعطلا عيزوت
، زايجلا بارطضا رطاخم ليمقت لجأ نم
.يمكييلا يمضعلا و
ةرورض جئاتنلا تحضوأ كلذك .نيسحتلا طاقن دحأ نيمدختسملا مسج داعبأ بساني امب ةبرعلا دي عضو رييغت ناك
رضلا دنع ايفيقوت نيمأتل ةبرعلا ةكرح حبك ةيلآ ريوطت و
ةر
، كلذل ةمزلالا ةوقلا ليمقتو .
ةيحاتفم تاممك :
عفدلا ىوق ،تايفشتسملا تادعم ميمصت ،لمعلا ةئيب ةسدنى مييقت ،تايفشتسملا تابجو تابرع -
ميمصتلا ،بحسلا
يرشبلا مسجلا تاسايق ،لمعلا ةئيب ةسدنى ئدابم ،لمعلا ةئيب ةسدنى قفو .
