PT 43 Intro to Office Ergo

Industrial Rehabilitation

the treatment of people who have acquired a disability or

disease during the course of their work, with the aim of

allowing them to return to work or to a new job

Ergonomics

- The science of fitting the workplace conditions and job demands to the capability of the worker

- Primary goal is to reduce the stress and eliminate injuries and disorders associated with overuse, bad posture and repeated activities

- Field of study involving application of knowledge about physiological, psychological and biomechanical capacities and limitation of humans

- This information is applied to the planning, design, job tools,

equipment and work environment to enhance safety and health

- "FITTING THE WORKPLACE TO THE WORKER"

Work conditioning

- Sessions are 1-3 hours for 2-3 days per wk

- usually 1 discipline

Work Hardening

- Sessions are 2-4 hours for 3- 5 days per wk

- Multidisciplinary, includes Psychosocial Management

Functional Capacity Evaluation

- Evaluation of person's capacity to perform work related to his/her employment

- Evaluates individual's health status, body functions, structures, work demands and the ability to perform job demand safely

Primary goal of Ergonomics

is to prevent WMSDs

Risk Factors in Ergonomics

- Awkward Postures

- Repetition

- Material Handling

- Force

- Mechanical Compression

- Vibration

- Extremes of Temp

- Glare

- Inadequate Lighting

- Duration of Exposure

Ergon

means work

Nomos

Means principles or laws

2 branches of Ergonomics

- Industrial Ergonomics/Occupational Biomechanics

- Human Factors

Human Factors in Ergonomics

- Related to the Psychological aspects or work

- Mental loading/ Decision Making

Industrial Ergonomics/Occupational Biomechanics

- Focuses on physical aspect of work and human capabilities

- Force, Posture, repetitions

Bernardino Ramazzini

- Born in 1633

- Father of Occupational Medicine

Main Goal of Ergonomics

Prevent WMSDs thru the application of principles to identify, evaluate and control physical workplace risk factors

MSDs are a class of disorders involving damage to

- Muscles

- Tendons

- Ligaments

- Joints

- Cartilage

- Bones

- Blood Vessels

WMSDs (Work Related MSK disorders) are also called

- Cumulative Trauma Disorders (CTD)

- Repetitive Motion Trauma (RMT)

- Occupational Overuse Syndrome

Ex. of WMSDs

- Epicondylitis

- Tendinitis

- De Quervain's

- Trigger Finger

- Reynaud's Syndrome (Vibration White Finger)

- CTS

- Back strain

the following are often associated with WMSDs

- Posture

- Forces/Compression

- Repetition

- Vibration

Postures

- Awkward

- Static

- Prolonged

Forces

- Heavy, Frequent, awkward lifting; prolonged loads

- Amount of physical effort required to accomplish a task

- Higher force usually placed upon, MUSCLES, TENDONS and JOINTS

- Prolonged exposure results to FATIGUE, OVERUSE, STRAIN, SPRAIN, leading to damage

Compression

- Gripping; FA pressure during computer work

- Concentrated force in small area

- can reduce blood flow or tissue irritation

MOST COMMON IN COMPRESSION

- Sharp or hard desk creating compression on FA or elbow leading to Neuropraxia to the nerves of the FA

Repetition

- ASSEMBLY LINE: Doing the same thing the entire day

- Doing the same motion or group of motions over a period of time

- different tasks may still use the same muscle group leading to overuse

Vibration

- Hand Arm Vibration / or

Whole body vibration

Single point vibration

- Common with tool use with UE

- Decreased blood vol to the extremities

- can cause vascular spasms, constriction of blood vessels in fingers

Whole body vibration

- Usually found in vehicles

- usually affects the spine

- can contribute to Chronic LBP

Neutral Posture

- Optimal body position to minimize stress and provide greatest control

- Least tension on the nerves, tendons, muscles, joints, discs

- Muscles at their resting length

Ideal Neutral posture

- Neck, shoulder arms relaxed

- Shoulders neutral not elevated nor in abd/add/flex/ext

- Neck not tilted

- Elbow by the sides

- elbow open at an angle

- FA neutral with thumb up

- Wrist Neutral

- Ears over the shoulders

- Hips over knees

- Knees over ankles

- Spine at a slight S shape with lowerback slightly concaved

Duration and Magnitude

Continuous exposure does not allow sufficient recovery time

Cold Environment

places greater aerobic demand to the worker; resulting

to faster fatigue; reduces dexterity causing the need to grip harder, causing compression and decreased blood flow; cold temperature also constrict the vessels

Hot/warm temperature

causes workers to move slowly, making the task longer, i.e. use of PPE decrease evaporation from skin reducing the body's ability to cool itself

Inadequate recovery

No time for stretching, alternating tasks, micro breaks to allow for recovery time

Other Risk factors in Ergonomics

- Duration and magnitude

- Temperature Extremes

- Inadequate Recovery

Other personal risk factors in ergonomics

- Age

- Gender

- Hobbies

- Smoking

- Obesity

- Prev injury

- Medications

- Fatigue

- Poor physical Conditions

Common signs and symptoms to look for(Early Identification may reduce the risk and severity of Injury)

- Painful aching joints, muscles; pain and discomfort

- Pain, tingling, numbness

- Shooting or stabbing pains

- Swelling or inflammation

- Warmth

- Stiffness or difficulty moving

- Burning sensation

- Pain at night

- Loss of strength and mobility

Anthropometry

- Measurement of Physical attributes of humans

- plays an important role in industrial design, clothing design, architecture and ergonomics

Primary Objectives in Anthropometry

- Enhance performance

- Reduce fatigue

Ergonomic design is planned for the?

95th percentile not the average person or the 50th percentile, meaning... 95% of the population can safely and efficiently

use the work area

Things to consider in Anthropometry

- Height

- Weight

- Reach (Horizontal and Overhead)

- Stoop

- Grip Strength

- Circumferential Measurements

- Limb length

- Age

- Gender

- Race/nationality

Worker's safety must consider the ff

- Safe clearances or heights

- Safe reach distances

- Symmetrical orientation

- Code requirements

- Safety ft

- Work Station design appropriate for workflow

BMI formula

weight (kg) (lbs)/ height (m^2)(in^2)

BMI

is used to broadly define Weight groups

Underweight

Less then 18.5

Healthy weight

18.5 to less than 25

Overweight

25 to less than 30

Obesity

30 or greater

Class 1 Obesity

30 to less than 35

Class 2 Obesity

35 to less than 40

Class 3 Obesity(Severe)

40 or greater

Measurement of Body fat

- use of skin fold calipers

- Usually RIGHT SIDE is measured as a common standard

- You have to make sure you are able to grab skin and layer of fat

- not very reliable in old people (due to skin folds, people with

abnormal fluid retention or the extremely obese (where fatty tissues are very tight)

Common error in measurement of body fat

people just grabs onto the skin)

Chest/pectoral body fat testing

diagonal fold between armpit and nipple

Abdominal body fat testing

vertical fold 1 inch (right) lateral to the navel

In some protocols this is taken as a horizontal fold (just make sure you are consistent

when you do your measure)

Thigh body fat testing

vertical fold between knee cap and top of thigh

Triceps and Biceps body fat testing

vertical fold between elbow and shoulder

Subscapular body fat testing

diagonal fold, below inferior angle of scapula, close to spine

Suprailiac (Supraspinale) body fat testing

diagonal fold above anterior iliac crest (between iliac

crest and umbilicus)

Lower back body fat testing

horizontal fold directly in line with kidneys, 2 inches lateral to spine

Calf body fat testing

vertical fold, largest part of the calf (if asked for medial calf, it is the medial portion of the tibia; if just calf use the mid posterior calf)

Mid axillary Body fat testing

mid vertical fold on the mid axillary run directly down center of

armpit

Essential Fat Normal Values in Women

10-12%

Essential Fat Normal Values in Men

2-4%

Athletes Fat Normal Values in Women

14-20%

Athletes Fat Normal Values in men

6-13%

Fitness Fat Normal Values in Women

21-24%

Fitness Fat Normal Values in men

14-17%

Acceptable Fat Normal Values in Women

25-31%

Acceptable Fat Normal Values in men

18-25%

Obese Fat Normal Values in Women

32% plus

Obese Fat Normal Values in men

25% Plus

Circumferential Measurements/Girth Measurement

- Used in the presence of edema in lieu of the volumetric Measurements

- Useful in measuring atrophy

- Mark some landmarks

- Measure with tape measure

- Can be done with muscles relaxed or contracted

Breadths Measurement

- Use of length caliper, tape measure or ruler

- Biepicondylar humerus

- Biepicondylar Femur

- Bimalleolar

Principle for a Range

- allow for adjustments in size, Intensity, duration of the product or system

- Accommodate Unexpected circumstances and maximize use

Design for Range

- Use from the 5th to 95th percentile

- Accommodate 95% and 50/50 of the mixed population group between males and females

Examples of Range

- Adjustable car seats

- Adjustable Desk height computer stations

- Safe platforms to use for small people when reaching in high places

- Aids for reaching

- adjustable footrests

- Different sizes of chairs, shoes, tools

Principle for the extremes

- Accommodate largest % of the population:95th to 100th percentile

- Clearance, load, tolerance, Girth (doorways, strength of

ladders)

- Reach, strength (control buttons, force to operate lever or

button)

Design for the extreme

- Consider the extremes 1-5th percentile and 95th -100th percentile

Examples of Extreme

- Exits

- Control Configurations

- Safety Showers

Principle for the average

- Design for the 50th Percentile

- Accommodates small population group

- Acceptable for short term use

Design for the average

- Use as a last resort

- Excludes the other 50% of the population

- Hard to estimate as there is no such thing as "Average"

Examples of Average

- Self serve check out counters

- Water fountains

Computer Workstations

- Static posture, all day long

- Stretches & contracts muscles inappropriately

- Causes stress to the body

- Poorly designed workplace will cause neck and back pain, resulting to decreased productivity and job dissatisfaction

Common Causes of WMSDs

neck & shoulder fatigue, LBP, numbness & discomfort on legs

Proper Desktop Position

- Neutral head position

- Top of monitor level with eyes

- Shoulders relaxed and back straight; spine at 90°

- Monitor about an arm's length away

- Elbows close to body at a 90°-100° angle

- Wrists in straight line with forearm

- Support for natural back arch; backrest for lumbar support & to decrease pressure

- Hip & knees at a 90°-100° angle

- Chair adjusted so feet are flat on ground (or with footrest); ankle in neutral

Key points in office ergonomics

Eyes and screen

Hands and keyboard

Back/legs and chair

Feet and floor

Physical risk Factors

Awkward postures (hands, arms, wrists, neck, shoulder, and legs)

Static loading

Repetition

Duration

Contact stress (thighs, arms, palms)

Contributing Risk Factors

Inadequate rest/recovery

Extremes of temperature

Stress on the job

Fatigue

Cradling phone with head and shoulder would lead to?

tightness of upper traps & contralateral obliques or quadratus lumborum

Computer Vision Syndrome

Strain

Neck, shoulder, and back pain

Headaches

Blurry vision and dry eyes

Solution in Computer vision syndrome

ncrease font size

Correctly position monitor

Minimize screen glare

Wear the right glasses

Take a break (As per the Occupational Safety and Health Administration, must take a 10-minute break per hour)

Indications for Computer workstation evaluation

Person observed in an awkward posture

Person looks uncomfortable or with complaints of discomfort

Elbows are not at 90°

Wrists deviated

Trunk leaning forward

Feet are not supported

With history of MSK concerns or injuries

With complaints of aches and pains

Evaluation of Workstation

Duration of usage (mouse, keyboard, sitting)

Keyboard or mouse us of >4 hours has to be evaluated

Use of other items (calculators, book stands, phones)

Workstations

Fixed height of desks, chairs, etc.

frequently used items should be placed?

directly in front of the person to decrease need to reach forward, flex trunk, and hyperextend arms

infrequently used items may be placed in?

comfortable reach zone

Arms can be fully extended but trunk still not flexing forward

Reach

Make sure items are accessible

Analyze general layout to check if items can be moved closer to the user

Analyze the tasks and the workflow of the worker

Use stools when reaching overhead

Check for general organization, cleanliness, and housekeeping concerns as these can cause barriers

MOST IMPORTANT TOOL in the office

Chair

Chairs

Affects posture, circulation, and pressure in spine

ONE SIZE DOES NOT FIT ALL

Considerations in chairs

Ergonomic factors - comfort and size

Adjustability - range and ease

Durability - cost, life, maintenance

Safety of adjustment; no hazards

Other features such as arm rests, casters, and footrests

Measurement of chair

2-inch thigh clearance under desk

2-inch space between front edge of chair and popliteal area (seat pan shorter than thighs)

Check popliteal height; distance between floor and side of knee

Hips higher or same level as the knees

Feet should be touching the floor

Consider angle of seat pan in patients with LBP

Lumbar support on the small of back

Arms on the sides with elbows at 90°-110°

Arms should NOT be on arm rests while keyboarding; only for resting

Shoulders neutral and not elevated or depressed

Negative tilt

top higher than bottom