Ergonomic practices in Africa: Date palm work in Algeria as an example

Abstract

BACKGROUND:

Despite the call for the application of ergonomics in developing countries, the African share of ergonomic studies is modest. Date palm farming is considered one of the most important economic resources in hot and dry areas. In African countries, including Algeria, there exist millions of date palms. Date palm work can be precarious and associated with higher rates of work related musculoskeletal disorders.

OBJECTIVE:

This paper aims to:

Reveal how the workers climb the trunk of the date palm to get to the crown.

Detect the amount of work related musculoskeletal disorders (WRMSDs) in date palm trees work, and how to combat it.

METHOD:

The descriptive method was used.

RESULTS:

Objective 1, Majority of date palm workers are still using the traditional methods, i.e. free climbing, and belt aided climbing. However, a minority of workers have started using modern methods i.e. ladders, climbing devices, and modern technology (e.g. hydraulic lifts). Objective 2, the workers complained about WRMSDs presence in the shoulders, hands, wrists, lower back, hips knees, and feet. Efforts to combat these WRMSDs are personal, educational and scientific efforts.

CONCLUSION:

Regarding climbing, the traditional methods are still dominant, and the use of technology is very limited. As regards WRMSDs, date palm workers complain about their presence in many parts of the body.

Keywords

Developing countries free climbing aided climbing WRMSDs

1 Introduction

For more than fifty years, early ergonomists either from industrially developed countries [2 , 9], or from industrially developing countries [1 , 4] called for the application of ergonomics in industrially developing countries to assist them in their developmental processes.

Indeed, ergonomists from industrially developing countries applied ergonomics to many workplaces, traditional machines, and jobs in the field of what was called, traditional ergonomics [10 –18]. But despite these actions, the African share of ergonomic studies is modest when compared to the ergonomic work done in other continents.

African countries are predominantly agricultural countries [19, 20]. Their economies are dependent on agriculture. In addition, a large portion of the population lives and works in rural areas. Work in these areas is still done traditionally [21, 22].

Various efforts have been attempted to develop agricultural work in Africa [22 , 25–29]. But most or all of them dealt with the issue from the economic and technology transfer approaches. There is no doubt that these approaches helped to develop African countries, but it is necessary to give an opportunity to ergonomics, which has contributed significantly to the development of the economies of industrialized countries.

Date palm (Phoenix dactylifira) farming is considered one of the most important economic resources especially in hot and dry areas in Africa. In Algeria, according to Bouguedoura, et al. [5], the number of date palms is in the millions. The number of people who work in the date palm industry is also very large. The majority of date palm work (climbing, dethroning, pollinating, bunch thinning, dry leaves pruning, bunch covering and date harvesting) is carried out after the farmer climbs the trunk to reach the crown. The worker climbs the palm tree, which may be about 21–23 meters in height, barefooted, and rarely uses a belt or a rope for support.

The work is precarious and associated with significantly higher rates of WRMSDs [30 –32]. The major source of precariousness is falling which can result in death or disability. The farmer may fall as he climbs the trunk of the palm, especially when he catches an old leaf base or when he puts his foot on a cracked old leaf base. He may also fall while connecting the belt rope to the belt. Likewise, he may fall when he accidentally cuts off the rope during the cutting of dry leaves.

There have been numerous incidents of workers falling from the tree trunk. Some of these incidents are:

In 1986, a worker was cutting the dry leaves, he did not press the belt firmly. Since the belt was not attached to his abdomen, he fell down from a height of about (8 m). He is now paralyzed using a wheelchair.

In August 2012, a worker fell and broke his spine when he accidentally cut his belt rope while cutting the dry leaves. In another incident in July 2015, a worker fell from a date palm trunk because the knot of the belt rope opened without being noticed. This incident resulted in the farmer breaking his spine.

In addition to falling accidents, date palm farmers complain of WRMSDs in several parts of the body. However, the major source of WRMSDs is that date palm workers have to do various tasks and operations on the palm crown with a large amount of static work (gripping tools for long time, holding the arms out or up to perform tasks, standing on unstable surface for prolonged periods, bending, and adopting awkward postures).

To address these problems, it is necessary to take advantage of the ergonomic interventions which make the workers work comfortably, safely and effectively, while at the same time leading to increased production quantitatively and qualitatively. Therefore, this paper seeks to address the following questions:

How the date palm workers climb the trunk of the date palm to get to the crown?

What is the amount of WRMSDs in date palm trees work, and how to fight it?

2 Methodology

2.1 Method

To achieve the aims of this study, the descriptive research method, was used as follows:

1) Library research. A literature survey was conducted as follows: Initially, an electronic search in the following data bases: Ergonomics Abstracts, Scopus, and Science Direct, was conducted using a variety of key words (date palm agriculture, mechanization of date palms, occupational risk factors among date palm workers. In addition, manual searches were carried out in the following journals: Accident Analysis and Prevention, Ergonomics, Applied Ergonomics, Human Factors, International Journal of Industrial Ergonomics, Reviews of Human Factors and Ergonomics, Theoretical Issues in Ergonomics Science, Human Factors and Ergonomics in Manufacturing, Ergonomics in Design, WORK: A Journal of Prevention, Assessment & Rehabilitation, and Le Travail Humain. The result of this survey was the collection of more than 400 items, mainly articles.

Second, the articles obtained were then classified into two categories: climbing date palms and falling, and occupational health and WRMSDs of date-palm workers.

2) Field research. The Nordic Musculoskeletal Questionnaire [33] which is an internationally respected instrument was used to assess the WRMSDs among the date palm farmers. Before its use, the questionnaire was translated into Arabic, the language of date palm workers in Algeria.100 questionnaires were distributed to farms in the region of Ziban (Algeria). The workers who were able to read were asked to answer the questionnaire themselves. For non-reading workers, the questionnaire was applied to them in the form of a structured interview. Regarding the validity and reliability of the questionnaire, the researchers relied on the studies of other researchers who used it, especially the studies on farm workers [34 –41].

2.2 Study sample

One of the researchers (MM) requested the help of the Directorate of Agriculture in the governorate of Ouled Djellal (Biskra, Algeria) to distribute the questionnaire to the workers in the date palm cultivation. A total of 100 questionnaires were distributed on a randomly selected sample of workers. The response rate was 63%. After examining the retrieved responses, seven of them were found to be incomplete and were discarded. The analysis of the results is based on 56 questionnaires. The average age of these workers was 42 years with a standard deviation of 5.3.

3 Results and discussion

3.1 How do the workers climb the trunk of the date palm to get to the crown?

It has been found that climbing the date palm trunk is done in two ways: the traditional and the modern ways.

The traditional way: Here we can distinguish two methods:

Free climbing: The number of farmers who use this method is constantly decreasing because of the risk of fall and fatigue at work. In this method, the worker climbs the trunk of the palm using his hands and legs with no aid (see Fig. 1). He places his two feet on the bases of the leaves, then raises his trunk with his hands to maintain his balance and prevent the falling. He continues his way up to the crown of the palm.

Fig.1

A farmer climbing date palm barefooted (the Monkey method).

This is considered “the Monkey way”. When reaching the crown, work is done with one hand while the other hand holds the worker’s body to the trunk of the palm. The workers have used this method for years, but now realize that it is very tiring as is associated with high amount of static work. Both arm and leg muscles are doing static work for long periods of time. For this reason, the worker is forced to change from the dominant hand to the non-dominant hand when fatigue sets in in order to finish the work. This method is mainly used to accomplish the tasks completed below the crown such as dry leaves cutting, ripe dates picking, and bunch cutting of some date varieties.

Aided climbing: Human beings have been in a continuous pursuit to improve working conditions. According to Bhuiyan & Baghel [42], continuous improvement is a “culture of sustained improvement targeting the elimination of waste in all systems and processes of an organization”. In this context, the use of the belt first appeared (see Fig. 2). The belt is a man-made- plexus, made of thin ropes (10 to 15 mm) that forms a rectangular piece with a width of about 100 mm, and a length of about 800 mm. An overhand loop is stitched at one end of the belt. However, at the other end, a rope with a length of about three meters is fixed. Workers usually choose the rope based on their own experience or the experience of their colleagues. Therefore, they do not receive accurate information about the type of rope they should use. Therefore, the design of the working belt may not achieve the industrial security required in the workplace. Other researchers in other developing countries have mentioned this phenomenon too [62].

Fig.2

Aided climbing using a belt.

The date palm workers are alerted to the need to connect the belt to the abdomen area before embarking on the climb due to the number of the falls that have occurred and painful consequences (disabilities, death, and psychological problems). Workers, who obtained the knowledge of the correct type of rope, reduced the incidence of falls very dramatically. These days, we see a large number of date palm farmers use this method.

The modern way: As date palm growers realized the difficulty of climbing and the danger of falling from the trunk of the palm, they began to search for safer alternatives that facilitate climbing and working on the trunk. Here are some solutions that have been introduced:

The use of ladder: Despite the fact that there are many types of ladders, the one that can be used is the extension ladder (see Fig. 3). It is a ladder that can be extended as needed. It is located at different lengths where the total length after the expansion is about 15 m. When used properly, it is leaned against the date palm trunk so that it does not move. This helps prevent the farmer from falling. The ladder is not widely used in the Algerian date palm orchards. The major reason may be the fact that orchards are not designed for using ladders. Date Palms water basins and canals may hinder the use of these ladders. In addition, the installation of ladder on a palm trunk is time consuming and tiring process. For this reason, the use of the ladder in the Algerian palm groves is limited compared to its use in date palm oases in Coachella valley in Southern California (USA), for example.

Fig.3

Climbing using an extension ladder

The use of climbing devices: In a visit in 2017 to the Technical Institute for the Development of Saharan Agronomy (Biskra, Algeria), an engineer has developed a date palm climber (see Fig. 4). This device is made up of two pieces: upper piece and a bottom one. The two pieces are connected to the trunk of the palm in a safe manner which allows them to move upward or downward. The farmer sits on the upper piece and lifts the lower piece with his feet. Then stands on the lower piece and lifts the top piece with his hands to a higher level and so up to the crown of the palm. There he does the work for which he is climbing the date palm. Although the institute tried to market the device, there was little demand. The use of the device needs a lot of time to install and to dismantle. In addition, moving it from one date palm to another is not easy. Many date palm workers in the area of Ouled Djellal, showed that they knew nothing about it.

Fig.4

Climbing using the climbing device.

The use of modern technology:

Date palm workers have indicated that they have heard about the use of some newer technology in date palm cultivation in some countries, but they themselves do not own or use it. The following research studies reinforce the need for newer technology for date palm workers to promote higher productivity and safety for the workers.

Aly-Hassan, et al. [43] point out that the technology that was designed to work with palm trees does not exist. What exists is machinery for operation in the field of industry. Thus, Aly-Hassan, et al examined a large number of machines to see to what extent the machines can be used in date palm fields. Two machines were selected: the BEN (10) which is a French hydraulic (10 meter high) lifting machine and the aerial work platform which is an American machine [43]. The goal of the researchers was first, to see whether the two machines could be used in date palm farming and second, to know which parts or pieces had to be modified to make machines usable in date palm orchards. Finally, to see to what extent the modified machines were suitable and capable of helping date palm workers to do their work properly and safely. As well as to see how, the machines made ready for use in date palm plantations.

Al-Suhaibani et al. [44] first measured the length and size of date palms in different orchards. Then, the land of the palm plantations has been cleared to see the nature of the plant and the nature of the machine that can move without difficulty. In light of these two variants, the initial shape of a machine that could be used to lift the workers to the palm crown was suggested for design.

Fadel [45] developed what he called a date palm tree service machine. This machine is fixed on the back of a traditional 80 horsepower agricultural tractor. Also, it is totally dependent on the hydraulic capacity of the tractor. The machine can carry the worker and the tools he needs on the service platform to a height of up to 4.5 meters. In addition to the work he does, he can maneuver his workplace to move right and left, up and down. In order to protect both the worker and the tree from any failure, Fadel mentioned that attention was paid to providing security measures during design.

Jahromi, et al. [46] proposed the Lifting Model for Gripper Date Palm Service Machines. The researchers claim that the gripper machine was manufactured in such a way as to be fixed firmly to the trunk of the date palm without causing any damage to the trunk. Further, they claim that it can hold to the trunk of the date palm no matter what the circumference of that trunk is. The machine consists of four grippers, two at the bottom and two at the top. When the machine is placed on the trunk, the worker sits in a chair and controls the lifting, lowering and rotation around the trunk in a way that enables him to carry out his various functions under or inside the crown. The researchers noted that during its conception, they took into consideration the level of security.

Garbati-Pegna [47] designed the self-moved ladder which is a self-contained telescopic ladder that can reach a height of 15 meters. It was mounted on a small tracked dumper. The ladder is moved by the hydraulic system of the dumper, while its extension is carried out with a manual winch. The author mentions that the self-moved ladder is simple and does not require any effort for the worker who can then climb the trunk up to a height of 15 m. And that laying and extending the ladder to a maximum length takes about 60 seconds.

In addition to these achievements, there is the use of the robotization in palm cultivation. Throughout history, man has been trying to look for ways to minimize work and prevent occupational diseases and accidents. In recent years, humans have discovered that robots can achieve this. For this reason, robots have entered the field of farm work [48, 49]. As to date palm farming, Shapiro et al. [50] built a robot for date palm work. Similarly, Razzaghi et al. [51] designed the Mechanical Analysis of a Robotic Date Harvesting Manipulator. Further, Asfar [52] developed a robot that can climb the date palm tree to accomplish some operations on the trunk.

The aforementioned examples contribute to the development of date palm farming not only in Algeria, but in all countries interested in date palm cultivation in the world.

3.2 What is the amount of WRMSDs in date palm work, and how to combat it?

Prevalence of WRMSDs in date palm farming: It is seen in Table 1 that WRMSDs are prevalent among date palm workers. The workers complained about their physical ailments in the shoulders, hands and wrists, lower back, hips, knees and feet throughout the work week.

Table 1
Prevalence of WRMSDs in Nine Different Body Parts among Date Palm Farmers (n = 56)

Body part 7-Day Prevalence 12-Month Prevalence

Number % Number %

Neck 18 32.2 15 48

Shoulder 51 91 52 93

Elbows 19 34 14 25

Hands/ Wrists 55 98 56 100

Upper back 49 87.5 39 69.5

Lower back 54 96.5 51 91

Hips 49 87.5 29 52

Knees 51 91 49 87.5

Feet 56 100 53 94.5

Body part	7-Day Prevalence	12-Month Prevalence
Neck	18	32.2	15	48
Shoulder	51	91	52	93
Elbows	19	34	14	25
Hands/ Wrists	55	98	56	100
Upper back	49	87.5	39	69.5
Lower back	54	96.5	51	91
Hips	49	87.5	29	52
Knees	51	91	49	87.5
Feet	56	100	53	94.5

These results indicate that workers in the date palm farming industry are exposed to WRMSDs in multiple areas of the body, which indicates that this type of farming, like other types of farming (oil palm, wheat, tea, apple, livestock, and tomato work), is not as safe and trouble-free as previously thought [23 , 61].

Preventing WRMSDs: Several efforts to deal with WRMSDs among date palm workers are noticed, these can be classified into three categories:

Efforts by the workers:

Early morning work: Date palm workers carry out their work in the early morning before temperatures rise dramatically. It turned out that at this time of day they are very active and do not suffer from accidents such as falls [53].

Use of wrist brace: Date palm workers wear wrist braces to overcome the pain that can afflict the wrist. Workers do a lot of heavy work such as lifting, carrying and pulling while on the trunk, or inside the crown of the palm. These work movements cause a lot of pain especially in the hand wrist. Therefore, they use the braces to relieve the pains. These practices are in line with what many researchers have suggested, especially in sports [54 –56].

Tying the back belts: Some workers have shown that tying the belt to the waist area enables them to more frequently move freely the different parts of the upper half of the body. They have shown that movement, if found, diminishes the amount of static work leading to pain at least in the wrist, shoulders and hands. This is consistent with U.S. Department of Labor directives [57].

Efforts by the Directorate of Agriculture in the area:

Educational Interventions: From time to time, the Agriculture Directorate invites some date palm workers to attend a simple lecture by a regional doctor on WRMSDs. In each session, which lasts about an hour, simple information is provided about WRMSDs, how they occur, and how they can be overcame. Then a debate is opened, and questions are answered.

Distribution of brochures: a small folded brochure with short and simplified information about WRMSDs is given to individuals.

Efforts by scientific research centers in the area:

They take the form of inventing apparatuses which reduce work pressure and risks. The following are some examples for harvesting, and pollinating:

Harvesting: At the Center for Scientific and Technical Research on Arid Regions (Biskra, Algeria 2014), Nourani and Garbati-Pegna [58] and Nourani et al. [59] designed a machine that can harvest date bunches while the farmer is on the ground. The machine consists of four parts: the base of the machine, the basket for collecting dates, the device of raising or lowering the basket, and the tool that cuts date stalks. After the base is installed on the trunk of the palm, the basket is lifted until it reaches the date bunch. The farmer adjusts the basket to be directly under the bunch, and then he lifts it up to enter the basket. Then the cutting device is operated to cut the bunch. The chopped dates are then brought down to ground.

Pollinating: At the Center for Scientific and Technical Research on Arid Regions (Biskra, Algéria), Nourani et al. [60] talked about an instrument used to spread pollen powder on the date palm flowers while on ground. The length of the instrument’s pipes is adjustable to the length of the date palm. The authors have found that the mixture in which the ratio of pollen to wheat flour is 20% is the optimum ratio for obtaining dates of excellent quantity and quality. However, the instrument was originally invented by L’Institut Technique de Développement de l’Agronomie Saharienne (ITDAS).

Although the above efforts may be more time-consuming than conventional methods, they seem to be safer. With repeated use, date palm workers become more familiar with them, and the tasks are less time-consuming.

Limitations of this study: All studies have limitations. However, the major limitations of this study are:

Sample Size: It was noted above that the researchers distributed 100 questionnaires to the workers, but only 59 responses were received. It will therefore be difficult to generalize the results to members of the community. Thus, the size of the micro sample is one of the limits of this study.

Method: The researchers used the quantitative approach, especially in the second part of the research (WRMSDs). They know that the quantitative approach, if supported by a qualitative approach, would have produced more accurate and realistic results. Therefore, the nature of the methodology used is another limitation of research.

Data Collection Procedures: When researchers distributed the questionnaires, they requested the workers to answer accurately. None of the researchers were present during the response time. Thus, the workers (or at least some of them) may not have answered the questionnaires themselves and accurately. This may reduce the scientific value of the data obtained.

4 Conclusion

The current research sheds light on the cultivation of palm trees in Algeria. It focused on how workers climb the palm trees and on the level of musculoskeletal disorders they experienced in different regions of the body. It has been shown that the traditional methods to climb date palms, though risky for the lack of basic safety rules, still exist today. The worker climbs the trunk of the palm barefooted; either with no aid or using a belt that helps him perform his duties when reaching the date palm crown. It has also been found that workers in this type of farming are exposed to a multitude of musculoskeletal disorders, touching most parts of the body.

Despite the emergence of some technologies that facilitate the cultivation of date palm trees, it has been shown that the use of these newer technologies is still very limited, most notably for financial and structural reasons. The current research presented here is in fact considered ergonomic efforts used in the cultivation of date palms as long as these technologies seek to make the work comfortable and secure. Ergonomic considerations are not only neglected in Algeria, but in many other date producing countries of the world. Unless the date palm farm owners open the doors to include ergonomics, the health and safety of the workers will still be in jeopardy.

Conflict of interest

None to report.

Footnotes

Acknowledgments

The authors would like to express their very great appreciation to the date palm workers who participated in the research. The authors would also like to thank the Technical Institute for the Development of Saharan Agronomy and the Center for Scientific and Technical Research on Arid Regions (C.R.S.T.R.A) for their contributions. Special thanks also go to the students who collected the data for the research.

References

Sen

. The ergonomics society the society’s lecture 1983 the churchill college, cambridge, england, on 24 March. Ergonomics. 1984;27(10):1021–32.

Wisner

. Ergonomics in industrially developing countries. Ergonomics. 1985; 28(8):1213–24.

Abeysekera

. A comparative study of body size variability between people in industrialised countries and industrially developing countries, its impact on the use of imported goods. In International Symposium on Ergonomics in Developing Countries: 18/11/1985-21/11/1985, 1987, pp. 65–91.

Shahnavaz

. Workplace injuries in the developing countries. Ergonomics. 1987;30(2):397–404.

Bouguedoura

, Bennaceur

, Babahani

, Benziouche

. Date palm status and perspective in Algeria. In Date palm genetic resources and utilization 2015, Springer, Dordrecht, pp. 125–168.

Chapanis

. Ethnic variables in human factors engineering. Applied Ergonomics. 1975: 239.

Kogi

, Sen

. Third world ergonomics. International Review of Ergonomics, Taylor & Francis. 1987;1:77–118.

Wisner

, Pavard

, Benchekroun

, Geslin

. Anthropotechnologie: Vers un monde industriel pluricentrique. Octares; 1997.

O’neill

. Ergonomics in industrially developing countries: Does its application differ from that in industrially advanced countries? Applied Ergonomics. 2000;31(6):631–40.

10.

Nag

, Goswami

, Ashtekar

, Pradhan

. Ergonomics in sickle operation. Applied Ergonomics. 1988;19(3):233–9.

11.

Sen

, Sahu

. Ergonomic evaluation of a multipurpose shovel-cum-hoe for manual material handling. International Journal of Industrial Ergonomics. 1996;17(1):53–8.

12.

Chang

, Park

, Freivalds

. Ergonomic evaluation of the effects of handle types on garden tools. International Journal of Industrial Ergonomics. 1999;24(1):99–105.

13.

Helali

. How could you use the ergonomics ‘knowhow’ transfer management to enhance human working for sustainable improvements in industrially developing countries? Work. 2012; 41(Supplement 1):2730–5.

14.

Sen

. Ergonomic modifications of shovels in India. Environmental Management and Health. 1997;8(5):173–4.

15.

, Hsieh

. Ergonomics study on the handle length and lift angle for the culinary spatula. Applied Ergonomics. 2002;33(5):493–501.

16.

Kumar

, Mohan

, Patel

, Varghese

. Development of grain threshers based on ergonomic design criteria. Applied Ergonomics. 2002;33(5):503–8.

17.

Jung

, Jung

. Development and ergonomic evaluation of polypropylene laminated bags with carrying handles. International Journal of Industrial Ergonomics. 2003;31(4):223–34.

18.

Choobineh

, Tosian

, Alhamdi

, Davarzanie

. Ergonomic intervention in carpet mending operation. Applied Ergonomics. 2004;35(5):493–6.

19.

Torres

, Rodríguez

, Vina

. Preventing work-related musculoskeletal disorders in Cuba, an industrially developing country. Work. 2011;38(3):301–6.

20.

Cotula

, Vermeulen

, Leonard

, Keeley

. Land grab or development opportunity? Agricultural investment and international land deals in Africa. IIED/ FAO/ IFAD; 2009.

21.

Nwuba

, Kaul

. The effect of working posture on the Nigerian hoe farmer. Journal of Agricultural Engineering Research. 1986;33(3):179–85.

22.

Obi

. The role of ergonomics in sustainable agricultural development in Nigeria. Ergonomics SA: Journal of the Ergonomics Society of South Africa. 2015;27(1):33–45.

23.

Patel

, Pranav

, Biswas

. Nonfatal agricultural work-related injuries: A case study from Northeast India. Work. 2018;59(3):367–74.

24.

Ganesh

, Chhabra

, Kumari

. The effectiveness of rehabilitation on pain-free farming in agriculture workers with low back pain in India. Work. 2016;55(2):399–411.

25.

Doss

. Designing agricultural technology for African women farmers: Lessons from 25 years of experience. World Development. 2001;29(12):2075–92.

26.

Cleaver

. A strategy to develop agriculture in sub-Saharan Africa and a focus for the World Bank. The World Bank; 1993.

27.

Kelly

, Adesina

, Gordon

. Expanding access to agricultural inputs in Africa: A review of recent market development experience. Food Policy. 2003;28(4):379–404.

28.

Gabre-Madhin

, Haggblade

. Successes in African agriculture: Results of an expert survey. World Development. 2004;32(5):745–66.

29.

Salami

, Kamara

, Brixiova

. Smallholder agriculture in East Africa: Trends, constraints and opportunities. Working Papers Series N° 105. Tunis: African Development Bank; 2010.

30.

Grivna

, Aw

, El-Sadig

, Loney

, Sharif

, Thomsen

, Mauzi

, Abu-Zidan

. The legal framework and initiatives for promoting safety in the United Arab Emirates. International Journal of Injury Control and Safety Promotion. 2012;19(3):278–89.

31.

Marzban

, Hayati

. Ergonomic Assessment of Manual Harvesting of Date Palm. In 1st International Scientific Conference on Applied Sciences and Engineering, Kuala Lumpur, Malaysia, 2014, pp. 1–8.

32.

Grivna

, Eid

, Abu-Zidan

. Epidemiology of spinal injuries in the United Arab Emirates. World Journal of Emergency Surgery. 2015; 10(1):20.

33.

Kuorinka

, Jonsson

, Kilbom

, Vinterberg

, Biering-Sørensen

, Andersson

, Jørgensen

. Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms. Applied Ergonomics. 1987;18(3):233–7.

34.

Miranda

, Viikari-Juntura

, Martikainen

, Riihimäki

. A prospective study on knee pain and its risk factors. Osteoarthritis and Cartilage. 2002;10(8):623–30.

35.

Gallis

. Work-related prevalence of musculoskeletal symptoms among Greek forest workers. International Journal of Industrial Ergonomics. 2006;36(8):731–6.

36.

østensvik

, Veiersted

, Nilsen

. Association between numbers of long periods with sustained low-level trapezius muscle activity and neck pain. Ergonomics. 2009;52(12):1556–67.

37.

Scuffham

, Legg

, Firth

, Stevenson

. Prevalence and risk factors associated with musculoskeletal discomfort in New Zealand veterinarians. Applied Ergonomics. 2010;41(3):444–53.

38.

Bernard

, Courouve

, Bouée

, Adjémian

, Chrétien

, Niedhammer

. Biomechanical and psychosocial work exposures and musculoskeletal symptoms among vineyard workers. Journal of Occupational Health. 2011;53(5):297–311.

39.

Das

. Gender differences in prevalence of musculoskeletal disorders among the rice farmers of West Bengal, India. Work. 2015;50(2):229–40.

40.

Kolstrup

, Jakob

. Epidemiology of musculoskeletal symptoms among milkers and dairy farm characteristics in Sweden and Germany. Journal of Agromedicine. 2016;21(1):43–55.

41.

Douphrate

, Nonnenmann

, Hagevoort

, Gimeno Ruiz de Porras

. Work-related musculoskeletal symptoms and job factors among large-herd dairy milkers. Journal of Agromedicine. 2016;21(3):224–33.

42.

Bhuiyan

, Baghel

. An overview of continuous improvement: From the past to the present. Management Decision. 2005;43(5):761–71.

43.

Aly-Hassan

, Siaiz

, Ahmedi

, Abdaiia

. Modification of some industrial equipment to suit date palm orchards mechanization. In the 2nd Date Palm Symposium, King Feisal University, Al-Hassa, KSA 1986, pp. 543–554.

44.

Al-Suhaibani

, Babeir

, Kilgour

, Flynn

. The design of a date palm service machine. Journal of Agricultural Engineering Research. 1988;40(2):143–57.

45.

Fadel

. Development of a tractor-mounted date palm tree service machine. Emirates Journal of Food and Agriculture. 2005: 30–40.

46.

Jahromi

, Mirasheh

, Jafari

. Proposed lifting model for gripper date palm service machines. Agricultural Engineering International: CIGR Journal. 2008.

47.

Garbati-Pegna

. Self-moved ladder for date palm cultivation. InInternational Conference: Innovation Technology to Empower Safety, Health and Welfare in Agriculture and Agro-food Systems, Ragusa–Italy, 2008.

48.

Brynjolfsson

, McAfee

. The second machine age: Work, progress, and prosperity in a time of brilliant technologies. WW Norton & Company; 2014.

49.

Graetz

, Michaels

. Is modern technology responsible for jobless recoveries? American Economic Review. 2017;107(5):168–73.

50.

Shapiro

, Korkidi

, Demri

, Ben-Shahar

, Riemer

, Edan

. Toward elevated agrobotics: Development of a scaled-down prototype for visually guided date palm tree sprayer. Journal of Field Robotics. 2009;26(6-7):572–90.

51.

Razzaghi

, Massah

, Vakilian

. Mechanical analysis of a robotic date harvesting manipulator. Russian Agricultural Sciences. 2015;41(1):80–5.

52.

Asfar

. Palm tree climbing robot. Journal of Automation and Control Engineering. 2016; 4(3).

53.

Kjellstrom

, Holmer

, Lemke

. Workplace heat stress, health and productivity–an increasing challenge for low and middle-income countries during climate change. Global Health Action. 2009; 2(1):2047.

54.

Teulings

, Mandelbaum

. A new brace in the management of wrist pain in gymnastics. Medicine & Science in Sports & Exercise. 1992; 24(5):S46.

55.

Moore

, Popovic

, Daniel

, Boyea

, Polly JR

. The effect of a wrist brace on injury patterns in experimentally produced distal radial fractures in a cadaveric model. The American Journal of Sports Medicine. 1997;25(3):394–401.

56.

Grant-Ford

, Sitler

, Kozin

, Barbe

, Barr

. Effect of a prophylactic brace on wrist and ulnocarpal joint biomechanics in a cadaveric model. The American Journal of Sports Medicine. 2003;31(5):736–43.

57.

Occupational Safety and Health Administration. Ergonomics: The study of work. US Department of Labor. 2000.

58.

Nourani

, Pegna

. Proposed harvester model for palm date fruit. Journal of Agricultural Technology. 2014;10(4):817–22.

59.

Nourani

, Kaci

, Pegna

, Kadri

. Design of a portable dates cluster harvesting machine. Ama-Agricultural Mechanization In Asia Africa And Latin America. 2017;48(1):18–21.

60.

Nourani

, Kadri

, Benguiga

, Mehenni

, Salem

, Ferhat

. Réalisation d’un pollinisateur du palmier dattier. Revue Marocaine Des Sciences Agronomiques Et Vétérinaires. 2017; 5(3).

61.

Hermans

, O’Neill

, Motmans

, Lundqvist

, Roman-Liu

. Social partners cooperation for reduction of musculoskeletal disorders in agriculture. Work. 2012; 41(Supplement 1):5327–33.

62.

Meirelles

, Veiga

, de Castro Moura Duarte

. Efficiency of personal protective equipment used in agriculture. Work. 2012;41(Supplement 1):14–8.