Lifting Task Above The Al O Lifting example essay topic

INDEX PAGE INTRODUCTION 3 ERGONOMICS 4 OBJECTIVES OF ERGONOMICS 4 RESULTS OF ERGONOMIC APPLICATIONS 5 THE BACK STRUTURE 6 BACK AND BACK PROBLEMS 6 Back injuries 6 Causes of back injuries 7 The following are common causes of back injuries: - 7 Back injury prevention 8 Back injury-preventative techniques 8 Techniques 9 Strategies 9 ORIGINAL LIFTING MODEL 10 Strain index (SI) = 10 Action limit 11 Maximum permissible limit 11 Administrative controls 12 Engineering controls 12 Limitations of the NIOSH lifting model 13 LEGISLATIVE TRENDS: STANDARDS, GUIDELINES AND INTERVENTION PROGRAMMES 13 CONCLUSION 14 APPENDIX 1 15 REFERENCES 16 OCCUPATIONAL BACK INJURIES DURING MANUAL HANDLING OF MATERIAL INTRODUCTION Almost one third of all disabling injuries at work, temporary or permanent are related to manual handling of objects. Many of these incidents are avoidable and are the consequence of inadequate or simplistic bio-mechanical task analysis. Injuries associated with manual materials handling have grown substantially and are currently estimated to exceed several billion dollars annually in the USA. In addition to the compensation costs are the tremendous costs associated with the suffering of the impaired workers. Manual material handling injuries can result from lifting, lowering, pushing, pulling or carrying objects while performing activities.

Some of the most traumatic and costly manual material handling injuries impact on the back, more specifically the lower back has been the area of concern in most studies examining the low back pain associated with manual material handling. Lifting, handling and dragging loads involve a good deal of static effort, enough to classify as heavy work. The main problem with these forms of work however is not the heavy loads on the muscles, but much more the wear and tear on the intervertebral disks with the increased risk of back troubles. Back troubles are painful and reduce one's mobility and vitality they lead to long absence from work, and in modern times are among the main causes of early disability. ERGONOMICSErgonomics is concerned with the design of systems in which people carry out work.

Its name comes from the Greek words erg on which means "work" and monks which means "law". All work systems consist of a human component and a machine component embedded in a local environment. When designing any system where humans and machines work together to produce something, we need to know about the characteristics of the people involved and be able to apply this knowledge to the design. This activity is the fundamental function of ergonomics. Ergonomics came about as a consequence of the design and operational problems presented by new work systems which had evolved with the advance of technology. It owes its development to the same historical processes, which gave rise to the to other work system disciplines such as industrial engineering and occupational medicine.

The practice of ergonomics requires that knowledge about human anatomy, physiology, and psychology be applied to the design of work systems. Particular emphasis is placed on the design of the human - machine interface to ensure increased safety and usability of equipment and the removal of harmful stressor's. 4 OBJECTIVES OF ERGONOMICSErgonomics deals with the interaction between human and machine in the work environment. The main objective of ergonomics is to achieve an optimal relationship between people and their work environment. The two conflicting factors in this optimization process are workers productivity and their health and physical well being. That is, while workers should perform their job in the most efficient manner possible, they must also be protected against undue physical and psychological strain that may occur as a result of performing the required task.

2 RESULTS OF ERGONOMIC APPLICATIONS The following are some expected outcomes of applying the principles of ergonomics to the workplace: o Understanding the effects of a particular type of work on workers bodies and their job performance. o Predicting the long-term or cumulative effects of work on their job performance. o Assessment of fitness of the workplace and or tools to workers in performing a job. o Improvement of productivity and well being of workers by "fitting the task to the person, or fitting the person to the task". The result of such efforts is to achieve the best match between worker capabilities and job requirements. o Establishment of knowledge based support for designers, engineers and medical personnel for improving the productivity and well being of individuals. 2 THE BACK STRUTURE The back is a complex structure that is made of: Muscles Bones (vertebrae and their processes) LigamentsTendonsBlood supply Spinal and branched nerves The vertebrae are separated by the intervertebral disks. An intervertebral disk is a tough fibrous ring resembling a sac that is filled with a viscous fluid (gel like substance). These disks act as shock absorbers between the vertebrae and provide flexibility for the vertebrae. They are however the most fragile parts of the spine, especially the lower back (lumbar) region.

A major concern of biomechanics is to study compressive and shear forces acting on this disk. 2 BACK AND BACK PROBLEMS Back injuries If the intervertebral disk is ruptured or deteriorated, a nerve can be pressed by the bulging disks, or it can e pinched or pressed against the adjacent vertebra and, hence, pain is felt. Back pain is also caused when the muscles or tendons surrounding the spinal column become damaged. However, a back injury can be due to a variety of different problems, including: o Herniated intervertebral disk by sudden or jerky movement, extreme twisting, and or / strong push or pull. o Muscle spasm o Scoliosis (abnormal curvature of the spine - usually in the lateral direction Unstable (dislocated) vertebrae etc.

2 Causes of back injuries Most low back problems are due to damage to the lumbar intervertebral disks, especially to the L 5/S 1 disk, and to degenerative disk disease. The risk of developing a low-back problem increases with ageing since the disks become progressively less resilient, and susceptible to degenerative disk disease, allowing the disk to bulge into the spinal canal. Back injuries are seldom caused by single incidents. They are usually developed by long term wear and tear. The following are common causes of back injuries: -o Overexertion in manual material handling, e. g., lifting, lowering, pulling, pushing and carrying activities. o Poor lifting techniques such as: - Sudden or jerky movement, instead of smooth lifting movement. - Extreme twisting instead of pivoting.

- Lifting objects too far away from the body. - Lifting with the back flexed. - Using weak back muscles instead of the leg muscles, which are stronger than the back muscles. o Reaching above shoulders, especially when lifting an object Awkward workstation design o Poor postures in sitting and standing. o Vertical vibrations (experienced by truck drivers, construction machinery operators) o Accidents, including falling, slipping and tripping. o Weak muscles (especially back muscles) due to lack of exercise. Back injury prevention Efforts have continuously been made to redesign workplaces, tools and equipment, and / or work methods to fit the workers, and hence reduce work related injuries, including back injuries. However, job redesign cannot alleviate all back injuries. This is evidenced by the in cid ends in which back pains have been induced by a simple bending over to pick up, for example, a phone or sheet of paper from a desk, or a lightweight tool from the floor.

The most probable causes in such cases are the victim's lack of flexibility and loss of physical fitness. A variety of measures have been taken. Back injury-preventative techniques With careful application of engineering and administrative controls, exposure and injuries should both be reduced. In order to have a successful back injury reduction programme, the workers must become involved in the programme.

Place awareness and training principles that instruct employees in the following techniques of back injury prevention: Techniques Avoid lifting as much as possible. o Use carts, lift trucks or other mechanical assists. o Pushing instead of pull pushing allows the spine to remain in a neutral posture. o Get help from fellow employees. o Know the destination or where the load is to be placed in advance. o Know the safest and shortest routes to get to the destination of loads carried. o Get a good grip of the object being lifted. o Keep the object being handled as close to the body as possible. o Tuck the stomach in. o Lift smoothly and avoid jerk motions. o Avoid twisting while lifting. o Lift with the leg muscles, which are much stronger than the back muscles. o Avoid overexertion. o Reduce the load and make more trips of lighter loads. o Keep the back straight while lifting. Strategies Get help if the load is too heavy. o Don' t take more than you can carry safely. o Keep hands clear of pinch points to prevent crushing hands between objects. o Cross - tie when stacking. o Don't stack too high. o Don't carry a load so high that you can't see over it. Never block your vision. o Pushing is safer than pulling. o Always know your limitations. o Protect your hands with proper gloves. o Get a good grip of the load. o Never stand under a suspended load. Stand clear of overhead loads. o Be aware of and keep off all power lines - contact with power lines can be fatal. o Wear proper foot protection. 2 ORIGINAL LIFTING MODEL The Work Practises Guide defines manual lifting task as the act of manually grasping and raising an object of a definable size without mechanical aids. It was based on the thought that "an overexertion injury is the result of job demands that exceed a worker's capacity" and can be expressed by a strain index, as in the following equation: Job demands Strain index (SI) = Worker capacity Therefore, any lifting situation which this strain index exceeds 1.0 would present a potential for overexertion injury.

The Work Practices Guide was developed with the input of many experts and inputs involved epidemiological, biomechanical, physiological, and psychophysical studies of the capabilities and limitations of people while performing manual material handling activities. Lifting tasks were divided into three classes: o Acceptable (below the action limit) o Unacceptable for some individuals (between the AL and maximum o Unacceptable for most individuals (above the MPL), with engineering controls recommended to redesign the work to eliminate or reduce the manual material handling hazard. Action limit Because of a large variability in capacity of individuals, loads falling between the AL and MPL may be lifted if administrative (personnel selection and training) controls are applied since: o Musculoskeletal injury and severity rates increase moderately when workers perform a lifting task up to the AL (criterion). o A 350-kg biomechanical compression force on the l 5/S 1 intervertebral disk imposed by the conditions described by the AL can be tolerated by most young, healthy workers (biomechanical criterion). o Metabolic rates would exceed 3.5 kc l. min-1 for most individuals performing a lifting task above the AL (physiologic criterion). o Lifting loads up to the AL are acceptable to over 99% of male and over. Maximum permissible limit Lifting loads beyond the MPL should not be permitted, but engineering controls must be applied to lower the load within the acceptable range.

This limit has been set aside on four criteria (, bio mechanic, physiologic, and psychologic) as summarise d below: o Musclskeletal injury and severity rates increase significantly when a lifting task is performed above the MPL. o Biomechanical compression forces on the L 5/S 1 intervertebral disk above 650 kg are not tolerable by most people. o Metabolic rates would exceed 5.0 kcal. min-1 for most individuals performing a lifting task above the MPL. o Only about 25% of male and fewer than 1% of female workers would find a lifting task above the MPL acceptable. Administrative controls An administrative control is appropriate only for lifting jobs falling between the AL and MPL. As in any ergonomic analysis, administrative controls are recommended when engineering controls are not feasible. Examples of administrative controls for MMH activities include two (or more) persons lifting, limiting exposure through job rotation, training, and employee selection and placement. The ergonomist should continue to look for engineering solutions to reduce or alleviate the potential work problem. Engineering controls The ultimate goal of the ergonomist in job redesign is to eliminate job hazards through engineering design.

However, when lifting jobs fall above the MPL, lifting is not permitted and engineering controls must be applied to bring the job within the acceptable zone. Examples include: hoists and other mechanical assists, material handling aids such as conveyors, hand trucks, and lift trucks, job and work station redesign (e.g. removing barriers) and reducing the size and weight of object being handled. Limitations of the NIOSH lifting model In using the NIOSH WPG in real world situations, the following considerations should be taken into account: o Other MMH activities (e. g., holding, carrying, pushing, and pulling) are assumed to be minimal o When lifting activities are not performed, the individual is assumed to be at rest. o The work force is physically fit and accustomed to physical labour. o Safety factors commonly used by engineers to account for the unexpected conditions are not included. 5 LEGISLATIVE TRENDS: STANDARDS, GUIDELINES AND INTERVENTION PROGRAMMES Ever since the 19th century, government bodies in the developed nations have attempted, for social as well as economic reasons, to influence the way industry runs itself. Industries now have to comply with regulations, which limit worker exposure to the health - threatening aspects of their job. The requirement for good working conditions is not a new one.

The Occupational Health and Safety Act of 1970 requires all employees to "provide their employees with a workplace free from recognised serious hazards" irrespective of whether these hazards are covered by specific standards. If poor ergonomics constitutes a hazard, then employers are required to act. Ergonomic Safety and Health Management Rules specify what constitutes an "ergonomic hazard" and what actions to take to remove the hazard. The rules assist employers in complying with already existing legislation. 4 CONCLUSION Through compliance with legislative trends, understanding of the back structure, and Health and Safety training programmes, the universal prevalence of occupational back injuries can be reduced and even prevented.