Introduction to Ergonomics

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Ergonomics is a wide ranging field that seeks to design tools, equipments and tasks to optimize human capabilities. The term ergonomics was coined from Greek worda 'ergon' (meaning "work") and 'nomous' (meaning "rule"), so the literal meaning is "the rule of work" which is a handy concept to think about and then apply.

Overview of today's blog : you will get to know in brief about what is ergonomics, it's 3 main domains, different ergonomic principles, objectives and benefits of ergonomic practice in daily living for both common man and specially abled (disabled) people.

Rehabilitation practitioners (Occupational Therapist and Physiotherapist) have a distinct value in the area of ergonomics based on understanding the complex and dynamic interactions of the person, the task (i.e., job), and the context and environment (e.g., culture and personality, and where the task occurs). The skills and knowledge of rehabilitation practitioners in anatomy, physiology, and activity analysis make them highly qualified to work in the area of ergonomics, often within an interdisciplinary team. Rehabilitation practitioners are well equipped to facilitate the successful return of patient to optimal function through education and intervention of person, and adaptation or modification of physical environment like home, workplace or public areas.

Fig : Ergonomic concepts are considered in all the above areas.

Fig : Wrong ergonomics leads to awkward body posture and increases risk of various musculoskeletal disorders or cumulative trauma disease.

Fig : Wrong and bad sitting posture while doing computer or laptop work. Signs of bad posture includes excessive leaning forward, forward headed neck, excess stooping from thoracic spine, chair distance far from the table, no wrist or forearm or elbow support

The main objectives of implementing ergonomic principles and knowledge to humans daily occupational activities are:

To fit the task to the person (i.e to make a person-environment-occupation match). When designing a tool or planning a task, we need to consider human strength and limitations.
To work smarter and not harder : applying smarter ways or methods of working to improve work efficiency and decrease unnecessary energy expenditure. To follow handy, effective rule of work.
To make devices or environment user-friendly for working : User-friendly can also said to be ergonomic. Being user-friendly means that things are easy to understand and apply, mistakes are reduced and the humans are satisfied in his work performance. The concept applies to both physical issues as well as mental or cognitive ones. For example :

Doing a simple environmental modifications like by installing ramps or slope, for a disabled persons using wheelchair, in building or malls or commercial complex or stations etc. Ramps or slopes can prove beneficial, user-friendly or disability friendly as this will increase the social participation and ease wheelchair maneuvering for disabled people who are employed.
Using chair with adjustable height, for table-top work, in industries and offices can be beneficial for the above or below average height employee. User-friendly chair or ergonomic chair is a better option which will decrease the risk of back or neck pain amd and prevent adopting awkward posture while working.
Whenever possible using machines or device for completing the work instead of doing it manually. For example : for lifting, pushing, pulling heavy items.
Choosing correct knife design with respect to item to be cut. Knife's handle design also play an important role in improving the grip and ease of cutting.
Installation of commode in toilets for patients with hip or knee replacement, Ankylosing Spondylitis, Rheumatoid arthritis, Stroke, Spinal cord injury patients.

Fig : Ergonomic means to bring match or fit between person, activity/task and machine/device. Choose right person for a particular task and vice versa. Requirements of the activities like physical and cognitive abilities of the person should be considered.

Benefits of ergonomic practice in activities of daily living :

Good ergonomic can put people in a better position to do the job they are capable of.
Ergonomics can be applied to any human activity, including home chores and leisure activities. It can be applied in various environment and working sites like office, homes, industrial, parks, commercial complex, salons, rehabilitation center, hospitals etc.
When ergonomic principles are properly applied, ergonomics can reduce many cost for business including worker's compensation costs, turnover, absenteeism and variety of work inefficiencies.
Reduce turnover as new hires are more likely to find an ergonomically designed job within their physical capacity. Lower costs as workers’ compensation and other payments for illness and replacement workers go down.
Ergonomics practice in basic ADL, work, leisure tasks will improve quality and quantity of work by completing the activity with minimal effort and risk of injury and mistakes. This also leads to improved ability to focus and concentrate while performing task.
Ergonomically designed activities and work environment will decrease the physical, cognitive and psychosocial health complaints related to work. It helps to maintain the quality of life, reduce stress and increase work performance, increase work satisfaction and better work environment and social interaction is maintained.
Ergonomics can help the person with disability to fit in his environment by making adaptation or modifications at home, environment and workplace. Ergonomics can assist employers in accomodating disabled employees with various disabilities, ranging from muscular skeletal disabilities to chronic diseases such as multiple sclerosis, stroke, cardiovascular disease. Ergonomic practices helps to create a disability friendly environment. Examples:

CP chair in home and school
Adjustable table height or separate table for paraplegic patient, using wheelchair, at workplace.
Installation of ramps in commercial areas for disabled persons using wheelchair.
Adaptive devices like built-up handles, long handle reacher, universal cuff for upper-limbs range and muscle power limitations.

Large space to accommodate wheelchair in commercial areas, buildings, railway stations etc.
Separate toilet and bathroom for disabled person in malls, theatres, commercial complex.
Creating and spreading awareness amongst social community to include disabled person in workplace areas based on their abilities. Improving their self-confidence and quality of life (organizational ergonomics).

Fig : Ergonomic and Disability friendly environment created for person with disability (PwD)

Fig: Adaptive devices for person with upper limb impairments. These devices are also ergonomically designed to bring patient and activity fit in daily living work.

Ergonomic Domains of Specialization :

According to International Ergonomics association, there are 3 broad domains of ergonomics namely:

1) Physical ergonomics : it includes study of human anatomical, anthropometric, physiological and biomechanical characteristics that relate to physical activity.

This domain intervene to enhance occupational performance by bringing appropriate work activity and person fit.
Example: choice of tool, tool handles, comfortable and ergonomic chair, worksurface height and area, availability of ramps for disabled, adjustable chair or table height, machinary use, work related musculoskeletal problems, safety and health, material handling, etc

2) Cognitive ergonomics : it includes mental processes such as memory, working memory, retrieval, perception, reasoning, storage, motor response which affects the interaction between work activities and worker.

It focuses on worker by assessing the mental workload, decision making capacity, work stress, work skill and training, attention, executive functioning, human reliability, human-computer interaction etc.
If physical ergonomic design matches with the cognitive capacities then the work efficiency increases with less errors and productive boost.

3) Organizational ergonomics : it works on optimization of the entire workplace, sociotechnical systems, including their organizational structure, policies and processes.

It includes assessing work shifts and schedule, team work, communication, job satisfaction, supervision, virtual organization, telework, quality management, work paradigms, organizational culture, recruitment team etc.

Ergonomic Principles:

The changes and modifications made in workplace, work environment and object are implemented by considering the principles of ergonomics. Ergonomics also includes educating the worker/employee about correct postural alignment during specific work activity. Following are the ergonomic principles :

Work is neutral posture
Reduce excessive force
Keep things in easy reach
Work at proper height
Work in the power/comfort zone
Reduce excessive motion
Minimize pressure point or contact stresses
Provide clearance
Move, exercises, stretch and avoid static position
Maintain comfortable environment

(We will learn about it in detail in next blog)

Various musculoskeletal disorders which can occur because of wrong and awkward working postures, repetitive and excessive motion, poor work design. Each body parts has it potential musculoskeletal disorders (MSD) namely :

Head and neck MSD : Thoracic Outlet syndrome, cervical spondylosis, tension neck syndrome, cervical disc disorder.
Shoulder MSD: Rotator cuff tendinitis (impingement syndrome), bicipital tenosynovitis, Frozen shoulder or adhesive capsulitis.
Elbow MSD: lateral and medial epicondylitis, radial tunnel syndrome, cubital tunnel syndrome.
Wrist and hand MSD: tendinitis, carpel tunnel syndrome, ganglion cyst, trigger finger, De Quervain's tenosynovitis.
Lower back MSD: degenerative disc disease (lumbar spondylosis), strain of spinal muscles, sprain of spinal ligaments and capsule, risk of prolapsed intervertebral disc.
Leg MSD: Plantar fasciitis, tailor's bunion, tarsal tunnel syndrome, heel spurs, stiffness of knee joint.

For more information you can read our previous blogs :