Ergonomic workplace analysis involves assessing how well a work environment, including tools and tasks, aligns with the physical and cognitive capabilities of the workers. This analysis aims to identify potential risks of musculoskeletal disorders (MSDs) and other issues stemming from poor ergonomic design, and then to implement solutions to improve worker well-being, safety, and productivity. Ergonomic tools are designed to minimize strain and discomfort, promoting better posture and reducing the risk of injuries. Dr Aliya Shiar Muhammad

1. Ergonomic ; Knowledge
Tools And Techniques
Dr Aliya Shair Muhammad
DPT OMPT (IIRS)
BUMHS,Quetta

2. Ergonomic assessment/ work
assessments
 A systematic evaluation of a worker’s environment, tasks, and posture to
optimize safety, comfort, and efficiency.
Objectives:
 Prevent work-related musculoskeletal disorders (MSDs)
 Improve productivity and job satisfaction
 Ensure compliance with occupational health & safety standards
Assessment Areas:
o Workstation setup (e.g., desk, chair, screen height)
o Task analysis (repetition, force, posture)
o Environmental factors (lighting, noise, temperature)

3. Work Assessment
 1. Posture and Movement
Identify awkward or static postures
Evaluate repetitive motions and forceful exertions
 2. Tools and Equipment
Are they the right fit for the task?
Is there adjustability to fit the user?
 3. Work Environment
Adequate lighting, minimal glare
Temperature and noise control

4. Conti….
 4. Recommendations & Interventions
Ergonomic tools (e.g., keyboard trays, footrests)
Task redesign or rotation
Training on proper technique and posture
 Outcome:
Safer, more efficient, and more comfortable workspaces

5. ANTHROPOMETRY
The science of measurement of the human body
 Purpose:
• To provide concrete and scientific data for designing environments, products, and
workspaces.
• To create spaces that fit the largest number of users, improving usability and
accessibility.
 Application in Design:
Offers parameters of human size and shape (e.g., height,
reach, sitting posture).
Ensures comfort, safety, and functionality in design – from furniture to workstations and
public spaces.
 STATIC ANTHROPOMETRY : the science of measuring length, breadth, and width in the
human Population in a static condition.

6. Universal factors that influence human
size and shape:
 Gender
Men are larger than women, both overall and in limb length-
 Differences-Ethnic: groups in tropical climates have lower body weight than
those in colder temperature
 Aging
Beyond 30, stature decreases and bodyweight increases
After 50 and 60, body weight decreases.

7.  Some occupations,
such as soldier or jockey, are self-selective—a specific
size or weight is necessary to perform the job.
 The tendency for people of different occupations to have different
anthropometric proportions is poorly understood.

8. Cognitive And
Behavioral
Occupational Demand
Of Work

9. Cognitive demands:
 Demands associated with work tasks that require thinking, information
processing, learning, imagining, and anticipating.
The actions, efforts, and inter-actions required to conduct work tasks.

10. Cognitive Requirements of Job Tasks•
Critical thinking (judgment, analysis, reasoning, calculation,
manipulation, knowledge and ideas) generation of Creative thinking
using imagination and generating creative ideas
Information processing
Mental planning and scheduling
Communicating

11. Behavioral Demands:
 Definition:
The observable actions and responses a worker performs to complete
a task.
 Key Elements:
Posture and movement patterns
Task-related habits and routines
Interaction with tools, systems, and environment
 Ergonomic Relevance:
- Helps identify inefficient or harmful behaviors
- Guides the design of tasks and tools to promote safe, efficient, and sustainable
work practices

12. Behavioral Components of Work
Enactment of social
Interacting
Enactment of
worker
responsibilities and
Receiving
requirements
Executing
emotional job
demands
Enactment of
Management
responsibilities and
requirements
Enactment of
general
competencies and
accountabilities
Enactment of
specific
competencies

13. Psychosocial Factors In Work Related
Musculoskeletal Disorders:
 An individual who feels pain from a certain activity alters their posture to avoid pain. The new
posture places them at further risk for an MSD.
 Tasks become frustrating and therefore individuals may use excessive force while performing
tasks.
 Tasks that cause pain may result in workers using medications that may have side effects, or use
substances in an uncontrolled manner to deal with the pain and stress.
 Psychosocial factors that cause negative stress may cause the worker to develop a sedentary
lifestyle.
 The worker feels they need to skip breaks or work longer hours to meet job demands, which
results in less time away from work for the body to recover.
 The work is done in a hurried manner or more weight is carried at one time to help speed up the
work, but these actions add strain on the body.
 A common stress reaction is to tense muscles, particularly in the upper body and shoulders.

14. What psychological changes does a person
experience when they are exposed to
workplace psychosocial factors?
 The general stress response is based upon how the stress is perceived by the
individual. Although there are several theories, the general stress response
can generally be sub-divided into two categories - positive and negative.
 A positive stress response is one that is associated with stressors that are
surmountable or achievable. They are challenges that we believe we can
accomplish and with that comes a general sense of engagement,
determination, and interest.
 Negative stress responses are associated with challenges that we believe we
cannot accomplish. They are associated with feelings such as uncertainty,
disinterest, boredom, and anxiety. When discussing the workplace, these
negative stresses are linked to the psychosocial factors mentioned above: lack
of job control, excessive job demands, low job satisfaction, and lack of social
support.

15. Physical environment
 Lighting – Adequate brightness, reduced glare
 Temperature & Humidity – Comfortable and consistent levels
 Noise – Minimized distractions and hearing risks
 Workspace Layout – Clear pathways, proper positioning of equipment
Ergonomic Knowledge, Tools & Techniques:
 Workstation Design – Adjustable desks, chairs, monitor height
 Ergonomic Tools – Footrests, anti-fatigue mats, ergonomic keyboards/mice
 Assessment Methods – RULA, REBA, task analysis
 Training & Education – Proper posture, movement, and tool use

16. Ergonomic Assessment Methods:
1. RULA (Rapid Upper Limb Assessment)
 Evaluates posture, force, and movement in the upper body
(neck, trunk, and upper limbs).
Use:
 Ideal for seated tasks (e.g., office work, assembly lines).
 A score indicating risk level and urgency of ergonomic
intervention.
2. REBA (Rapid Entire Body Assessment
 Assesses whole-body postural risks, including legs, back,
arms, and neck.
Use:
 Suitable for manual handling, healthcare, or dynamic
tasks involving the full body.
 A risk score that guides need for changes in task or
workplace design.
3. Task Analysis
 Breaks down a task into steps or
components to understand physical,
mental, and behavioral demands.
Use:
 Helps in identifying repetitive actions,
awkward postures, and opportunities for
redesign.
Types:
 Hierarchical, Cognitive, and Operational
task analysis depending on depth and
focus.
Output:
 A clear map of the task that informs
ergonomic improvements.

17. Human Factors in Medical Rehabilitation
Equipment:
Product Development and Usability Testing
 Prototype testing.
The evaluation of a newly developed trial product by the end-users who represent
the target market.
 Efficacy testing.
A more formal process of performance testing in a controlled setting to
determine the effectiveness of the product.
 Magnitude estimation.
In psychophysical experiments that involves having a subject compare his or her
current sensation with a reference sensation.

18. What Is Usability Testing?
 Gathering openion::;;
Usability measures the quality of a user’s experience when interacting with a
product or system—
cost effectiveness and usefulness.
 Two international standards further define usability and human-centered
design:
.Usability :the extent, a product can be used by specified users to achieve
specified goals with effectiveness, efficiency and satisfaction in a specified context
of user.
• Human-centered design is characterized by the active involvement of users and
a clear understanding of user and task requirements; an appropriate allocation of
function between users and technology;

19. What Is User-Centered Design?
 “users throughout each phase of the design process”.
 In addition, a macroergonomic approach is often used …..
 Usability testing
 used to evaluate the interface between the user and a machine or technology, such as in
the computer industry…….
 However, usability testing also applies to products that are not considered machines, such
as workstations.
 Both complex equipment and simple equipment can benefit from experimental
evaluation that concentrates on users.

20. PROCESS
 The first step:
 identify subject matter experts (SMEs) and the user population…….
 Therapists consulting regarding the development of a new walker, they must first
become familiar with the equipment…..
 Once familiar with the equipment, the purpose of the equipment, the situations and
environments in which the equipment would be used, and the target populations,
 the team can move on to usability testing.

21. Process continue………
Second step: meeting …..to define groundwork for development of design objectives
and task and function analysis.
 Therapists’ expertise on life skills and experiences throughout the life span, human
development milestones, disease & its consequences will assist with developing
the test objectives and tasks.
 Techniques: focus groups and user workshops, informal discussions, interviews
(structured or open-ended), questionnaires, brainstorming, checklists, and
observations.

22.  3,4: The next two steps,: identify design objectives more clearly
and to conduct a task and function analysis .
 Design objectives focus on product features that affect performance,
safety, expense, acceptance, comfort, ease of use, and aesthetics.
 Inclusion: these objectives in initial product development helps confirm that
the product is effective, safe, and accepted by user groups before expensive
investments are made in product creation and large-scale production.

23.  Fifth step: the development of performance criteria…….
 sixth step: Measurement techniques…..
 objective measurements include reaction time, number of errors, and type of
error.
 Subjective measurements include user ratings of comfort, convenience, ease
of use, and aesthetics….

 Note: subjects are recruited and trained.

24. Process continue…….
 7th
step :A walk-through or trial of the evaluation process
 The eighth step: is the actual assessment; involves a comparison study of
several prototype designs.
 Subjects perform one or more of the reference tasks, and the investigator collects
and analyzes objective and subjective information.
 9: Finally, the evaluation process is conducted as either a formal or an informal
research project. The results are used to critique or redesign the product.

25. Design Objectives for Product Development
Primary
Walker, Lightweight, Adjustable height, Adjustable width,
Stability, Appropriate weight distribution. Ability to maintain
erect posture during use
Secondary
Comfort, Ease of use, Ease of adjustment, Ease of
storage. Portability, Optimum grip height, Shape, Size
Tertiary
Attractiveness, Convenience
The design objectives and the information gained from the task and
function analysis are used to develop performance criteria.

26.  One or two design for rigorous evaluation.
 1::;An experimental evaluation:
measurement of subject performance under contrasting
conditions in a controlled environment and use of experimental and statistical controls.
- A non-experimental evaluation does not require contrasting conditions or strict controls.
For example, evaluating a subject’s reaction time.
 2:;Formal assessments….
Have definite procedures and are well defined
 3; informal assessments
have less well defined objectives and procedures.(questionnaire vs
open ended group discussions)

27.  4:;Two-dimensional :
evaluations OF a product through checklists
 5 : three-dimensional evaluations :
- may use mock-ups or prototypes and can incorporate
either nonperformance or performance measurements.
- An experimental evaluation of two or more prototypes determines which design is better or
best according to user performance and preference.
- If only one product is evaluated, the assessment addresses the same design questions of
effectiveness, ease of use, accomplishment of the mission, and deficits or areas that need
improvement, but only for that one product.

28. PRODUCT DEVELOPMENT, EFFICACY TESTING, AND
COMPARISON TESTING OF AN ASSISTIVE WALKER
Product Development
•Design based on user needs, ergonomic principles, and mobility support.
•Focus on stability, comfort, adjustability, and ease of use.
•Iterative process: concept → prototype → testing → refinement.
Efficacy Testing
•Measures how well the walker supports movement, balance, and user safety.
•Includes user trials, gait analysis, and feedback on performance.
•Ensures product meets functional goals and clinical standards.
3. Comparison Testing
• Compares new walker design against existing models.
• Evaluates usability, comfort, efficiency, and safety across users.
• Helps identify advantages or needed improvements.