3550 Final Flashcards
(105 cards)
1
Q
What is anthropometry derived from?
A
Greek words “Anthropos”, meaning man and “Metron”, meaning to measure
2
Q
What is anthropometry?
A
AKA human measurement
Concerned with the physical sizes and shapes of humans
Measurement of size, mass, shape, and inertial properties of the human body for occupational, recreational, and design purposes.
3
Q
Anthropometry and ergonomics
A
User-centered design
- Achieve best match between product, user and task
Also want to match to the environment
4
Q
What defines anthropometric success?
A
- Efficiency (measured by productivity, task performance, etc.)
- Ease of use
- Comfort
- Health and Safety
- Quality of working life
5
Q
User-Centered Design (4)
A
- Empirical
- Iterative
- Participative
- Non-Procrustean
6
Q
Empirical
A
- Capable of being verified or disproved by observation or experiment
- Can we quantify whether or not it is usable?
Part of User-Centered Design
7
Q
Iterative
A
Cyclical process
1. Research of empirical studies
2. Design phase
3. Evaluate design empirically
Multiple cycles that you should be going through. This is specific to product design but can also be applied into individual ergonomic assessment. In step 1 is where you’d get most anthropometric values from (use tables more so than doing it manually).
- Once we have determined best way to design things go through physical design phase. Once product has been designed then we evaluate the design by having actual people use it. Not released to the masses immediately, have test groups to try product on.
Part of User-Centered Design
8
Q
Participative
A
-End-user should be included in design process
Part of User-Centered Design
9
Q
Non-Procrustean
A
-Deals with people as they are rather than as they might be - FJP!!!
Trying to fit product to person
Part of User-Centered Design
10
Q
Benefits of User-Centered Design
A
- Accounts for human diversity
- Accounts for the task
- Systems oriented
- Pragmatic – recognizes there may be limits to what is reasonably practical. Seeks to reach the best possible outcome within the constraints imposed by these limits
Need to design best product/space based on constraints you are given
11
Q
2 Types of Anthropometry
A
Physical or static
Functional or dynamic
12
Q
Physical or Static Anthropometry
A
o Obtained when body is in a fixed position
o Consists of skeletal dimensions between landmarks or of contour dimensions
13
Q
Functional or Dynamic Anthropometry
A
o Obtained when the body is engaged in physical activity
o The “functional” dimension reflects a composite of different body segments functioning together.
usually need static measurements and then apply them to certain dynamic situations
14
Q
Static and Dynamic Dimensions
A
- Physical analysis suggests that only the measurements of the body segment lengths in fixed positions need to be considered in the design of workplaces.
- Functional analysis implies that the acceptability of a workplace design has to be evaluated with respect to the needed movements of the body from one position to another.
- Seldom it’s all or none often do a mix of both.
15
Q
Anthropometric Data
A
Results obtained from these methods are statistical data that can be applied in the design of products, clothing, occupational, and recreational environments.
16
Q
Anthropometric Data Assumptions
A
- We assume the population and parameter / measurement of interest follows a normal distribution
- 5th and 95th percentile
- We assume the measurement we are taking follows a normal distribution and for this to be accurate need to take these measurements with a large population.
- Product design parameters is often set from 5th percentile female to 95th percentile male. This is done to account for the vast majority of the population.
17
Q
Why use anthropometry?
A
Natural postures and movements are essential for life and efficient work. Therefore, our surroundings should be suited to those in it
18
Q
To design the best product…
A
o Must know your user population
o The criteria for deciding on a population are functional and depend on the problem at hand
19
Q
What might cheaper products have
A
Some products that are cheaper might only be set to 50th percentile and have less adjustability.
20
Q
There is enormous variability in body due to:
A
- Age
- Gender
- Ethnic diversity
- Natural variability
21
Q
What are the 5 design principles?
A
- Custom-fit each individual
- Have several fixed sizes
- Make it adjustable
- Design for the extremes
- Select people whose bodies fit the existing design
Lumping 2 and 3 together is one of the most practical and best practices to take
22
Q
Custom-fit each individual
A
Best approach in terms of fit/comfort/safety, but laborious and expensive
- Some places have multiple employees at a station (shift rotation, or hourly). Would need to then account for each individuals. Best approach would be to make sure that everyone would fit and could work at that station
23
Q
Have several fixed sizes
A
Reasonable solution, but all sizes must be available and “between-sized” individuals may not be accommodated
24
Q
Make it adjustable
A
Approach that usually provide the best fit to all people
25
Design for the extremes
Appropriate solution when safety is the greatest concern
26
Select people whose bodies fit the existing design
Least appropriate solution. Should be avoided as much as possible (FPJ!!!)
All other options need to be explored before this. Want to avoid this as much as possible. Certain professions have criteria that needs to be met and ppl need to fit the existing parameters.
27
Designing Adjustable Ranges Typical
Standard practice is to design for the 5th-95th range for relevant characteristics of specific user group
- Marketability, safety and flexibility are important issues involved
28
Issue with designing for 5-95
Bittner (1974) – looked at 5th and 95th percentiles on 13 dimensions for a chair
Would have excluded 52% of population instead of 10% implied by percentiles
- body measurements are not perfectly correlated
- Just need to be above or below on one dimension
- The more you have the greater the chance someone is excluded
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Design for adjustable ranges process
Mitigates the likelihood of eliminating sections of the user population due to design limitations.
- Adjustability vs. Fixed Sizes
Harnesses, Helmets, bikes, office and car seats, seatbelts
- First step is to determine the critical dimensions, then design mechanism of adjustability with emphasis on ease of operation
- Instructions and/or training program on how to and importance of proper adjustment
30
Designing for Extremes Process
1. There may be a limiting factor in the design that will dictate usability
2. Design for maximum value of design features OR design for minimum value of design features
3. These are often very much about safety for the “outliers”
4. Traditionally, extremes have been addressed by designing for
- 5th percentile female (smallest)
- 95th percentile male (largest)
31
Designing for Extremes Safety
* When the sole purpose of something is for safety then you need to go to 1st percentile female or 99th male
* On final will be explicitly with what measurements he wants us to use. If told designing a general product for general purposed default to 5-95th. If it’s for safety default to the 1st to 99th percentile in cases like that.
32
Design for minimum dimension
Used to accommodate largest individuals
For example
- width of a grocery aisle
- width of a chair
- clearance dimensions
- escape hatch in airplane
* When we use a minimum set we account for the largest individuals. If we set the width of a grocery aisle to accommodate the largest person in a society then those who are smaller can fit. Minimum dimensions of aisles needs to be x.
- Smallest it can be is x will accommodate for larger people
33
Design for maximum dimension
Used to accommodate smallest individuals
For example
-a fire alarm
- bus seat height and depth
- reach dimensions
34
Anthropometric planes
1. Frontal (divides into front and back)
2. Sagittal (divides into left and right)
3. Transverse (divides body into top and bottom)
35
Anthropometric Measurements
Height
- From lowest point (often floor) to highest point on individual
Breadth (Width)
- Widest point (on individual) – measure from left to right
Depth
- Anterior to posterior
Distance
- Measuring from one reference point to another reference point
Curvature
- Measuring from one point to another but factoring in the curvature of the object/individual. Not a straight-line measurement. Factoring in curves!
Circumference
- Of a body segment
Reach
36
Seated measurements
◦ The seat and floor need to be parallel and horizontal.
◦ The knees need to be bent at a 90° angle.
◦ Thighs need to be placed in a horizontal position and the lower legs need to be placed in a vertical position.
◦ The feet have to be horizontally flat on the ground.
Want chair/stool that is adjustable so you can get into proper position.
* Want to hit this criteria so you are standardizing where measurements are taken from so measurements that are taken apply to all diff circumstances/objects
37
Stature Measurements
Need to be in 1 of 4 positions
Regardless of the position in which the subject is measured, consistency of this position within the sample group for which measurements are taken is critical.
◦ Standing upright naturally
◦ Standing upright erect
◦ Standing against a wall
◦ Lying supine
Which one you use depends on the context
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Standing upright naturally
Slumping effect is included in measurements.
39
Standing upright erect
Measurements can have a 2 cm difference when the subject standing either stretches to a fully erect position or just stands upright naturally.
40
Standing against a wall with shoulder blades, buttocks, and back of the head touching the wall
Extending a book or straight edge from the top of the head to the wall, making a mark on the wall, and then measuring the distance to the floor helps ensure the subject is fully upright and provides a mechanism for consistency between subjects.
41
Lying supine
◦ Provides the tallest measurement as gravity will not compress the spine.
◦ Taking measurements in the morning also provides the tallest measurement.
42
Lying supine
◦ Provides the tallest measurement as gravity will not compress the spine.
◦ Taking measurements in the morning also provides the tallest measurement
43
Anthropometric Equation
Measurement = m +/- (Z x SD)
if using 5th percentile subtract and 95th we add.
Have additional considerations on a chart
- 10 cm for walking
- 5 cm for general safety
- Tells you what to add to accommodate something like being slumped or wearing shoes.
44
2 variables in zone of convenient reach
1. Forward reach distance (r)
2. Vertical distance between the shoulder and the work object (d)
45
Zone of convenient reach equations
one for horizontal and another for vertical ZCR
Horizontal - ZCR2 = r2 - d2
in vertical it's HD = ...
HD is horizontal distance from wall
vertical is HD2 = r2-d2
can rearrange that equation and get the max height of a control above a worker's shoulder
46
Anthropometry Summary
1. Determine body dimensions important to the design
2. Define population
3. Determine what principle should be applied
4. Select a % of population to be accommodated
5. Locate anthropometric tables appropriate for population
6. If special clothing worn - add allowances
7. Build prototype and test using representative tasks
Physical dimensions - taken in standard and still positions
Functional dimensions - obtained in various work postures
47
Insurance
A practice or arrangement by which a company or government agency provides a guarantee of compensation for specified loss, damage, illness, or death in return for payment of a premium.
48
Pooled Liability
Thousands of ppl pay premiums every month and if something bad happens insurance company takes from that pool of money and give it to the person. It’s called pooled liability. Pool money together and pull from that pool when needed.
49
Disability Insurance
* Protects individuals from an unexpected illness or accident that leaves them unable to work and earn an income.
* Replaces between 60% and 85% of regular income, up to a maximum amount, for a specified time
50
How is insurance paid for?
Employer
- Mandated in certain industries
- taken off pay check
Self-employed
- Self-employed you are paying for separately but can choose coverage with best rates and what coverage you want.
Drawback of having insurance through employer is that you’re restricted in terms of what type and level of coverage you can get. Also are restricted to the company they choose.
51
What is the process of insurance?
Injury --> rest, recovery and rehab --> return to work
* Case manager is mostly in the second step leading into 3rd step
* Ultimate goal is to get employee through this process as quickly and “safely” as possible
52
Who is involved in insurance process?
Case manager which can be handed off to rehabilitation consultant
beneath them is employee, employer and treatment providers
Case manager for all intents and purposes works as a middle man and manages those 3 other parties.
Plan member is person who got injured and plan sponsor is the employer
53
Who is the rehab consultant?
Insurance companies are sometimes inundated with claims – if not enough case managers or have maxed out case load on employees they can hire out ppl to help them. So can be a consultant for hire. If a case manager was assigned a case and couldn’t do it on their own b/c of hefty case load they could pass it on. As a rehab consultant – the one being brought in – now also have to manage the case manager not just the other 3.
54
Typical documents required for claim
- Plan member statement
- Medical assessment and/or doctor's letter
Plan member statement is very lengthy. Personal info, medical history, explain what happened, what led up to injury, have you sought out treatment. Up to injured individual to get medical assessment
* If claim is going through an organization like WSIB – have a functional abilities form – need doc to fill this out. Most private companies also have a document for the doc but it’s not called the same thing, the point of the processes is the same though
55
What does the legibility adjudicator do?
Eligibility adjudicator will go through client info and determine if the claim is acceptable or not. Does the person meet the criteria for a claim or do they not?
56
Who needs to submit documentation?
Health care providers, employee and employer all need to submit documentation at some point during the claim
57
STD, LTD Duration
STD – provides coverage for 17-26 weeks (up to 6 months)
LTD – provides coverage for the long term (typically 2 years)
58
Ultimate goal of insurance claims
To have employee return to previous occupation with previous company.
59
STD vs LTD
STD - pays more, but doesn't last very long (might get closer to that 85% of wage, but only for 6 months)
LTD - pays less, but can last extended periods of time. Potentially forever.
60
6 stages of standard case management
1. Client identification and eligibility for case management services
2. Assessment
3. Planning
4. Implementation
5. Evaluation
6. Transition
61
Client Identification and Eligibility for Case Management Services
Step 1 in case management
INITIAL ASSESSMENT
* Ensure client understand rights and responsibilities
* Obtain consent
* Get the client’s report on the what occurred
* Identify and prioritize client needs
* Explain case management process to the client
* Ensure the client understands complaints and appeals process
* Communicate the criteria that indicate end of case management
* Provide information about options in the event of ineligibility
If we transfer from ST to LT to perpetual payments these are different processes. Might get ST but claim for LT might be shut down. Client needs to know what their rights are in that moment.
62
Assessment
Step 2 in case management
A. Information generated by assessments serve as the foundation for planning
* Assessments may identify the client’s values, goals, functional and cognitive capacity, strengths, abilities, preferences, supports, needs, etc.
B. The case manager needs to ensure the assessments take place in a reasonable time frame, while considering the manner and mode that is sensitive to the client’s situation (i.e., in person vs. teleconference, etc. )
C. Results should be shared with appropriate health practitioners (with the consent of the client).
Initial assessment is a one on one meeting – get to know you, consent, what happened. With plan member and case manager – often done over phone – can do at their house
- This assessment here in step 2 is done after initial assessment!
63
Common assessments in case management
Specialist
- Surgeon, physio, psychologist/psychiatrist, oncologist, etc.
PDA
- physical demands analysis - done later on
FCE
- functional capacity evaluation
- lengthy eval where you look at functional capacities of that individual – can look at medical history, passive/active ROM, lifting scenarios, functional moving assessments (using peg boards can see how long arms above shoulders or how long in squat)
- Also see FAE – functional abilities evaluation
TSA
- transferable skills analysis
ERGO
- basic ergo assessment
IME
- Independent medical evaluation
- encompasses a variety of these assessment all in one by diff medical providers – done in a legal claim – e.g., are deemed ineligible for LTD can get a lawyer and dispute that.
64
Planning
Step 3 in case management
* Discuss results with client
* Generate plan based on results
* Identify barriers
* Identify services and choices available for those services
* Support and optimize client’s independence
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Implementation
Step 4 in case management
A. Outline and facilitate agreement upon roles and responsibilities of all parties involved
B. Foster client independence
C. Maintain regular communication with all parties
D. Monitor client’s progress
E. Identify and act upon opportunities for improvement/areas of concern
F. Explain and reiterate the likely or potential transition alternatives, roles and responsibilities to the client at appropriate junctures that allow ample time for consideration, questions and adjustments.
66
Evaluation
Step 5 of case management
* Determine if reassessments are required
* Evaluate progress of plan and reconfigure/replan when needed
* Document quantifiable impact on movements towards client’s goals
* Identify gaps in services/supports
* This step is important if things aren’t going very well.
* This is more a re-evaluation process. If things are going well can skip this step!
* In the low likelihood that things aren’t going as planned then would go through another set of evaluations. All those assessments discussed last time can be done here. Transferable skills analysis is usually done here!!
- Sometimes info you get in evaluation stage makes you go back to planning stage. It’s not always this linear process!
67
Transition
Step 6 in case management
* Provide clients with information/resources
* Support client in their efforts to secure appropriate alternatives (if applicable)
* Maximize independence
* Address concerns about disengagement
* Need to include health care providers and employers that the case has been closed as well!
68
Options for RTW
Best case is same job with same company
o Return to own occupation (own occ) with modifications
o Return to alternative occupation (alt occ)
* Return to alt occ with a different employer
o Job search assistance?
o Transferable Skills Analysis? (TSA)
o Functional Capacity Evaluation? (FCE)
69
How does case management suit a kin?
Need knowledge regarding:
- Anatomy
- Exercise
- Injuries
- Psychology
- Management
- Professionalism
- Rehab planning
70
Considerations of working in case management
* Sedentary
* Heavily administrative
* Legal involvement
* Get to work from home on occasion
* Must be able to manage time well
* Must be meticulous
* Must be able to communicate well with a variety of clientele/practitioners
* Can include “detective” work
* Lots of training involved
* Can pay VERY well
* “Economic and Financial” incentives
71
What is a WMSD?
WMSD’s are diseases related and/or aggravated by work that can affect the upper limb extremities, the lower back area, and the lower limbs. WMSD can be defined by impairments of bodily structures such as muscles, joints, tendons, ligaments, nerves, bones and the localized blood circulation system, caused or aggravated primarily by work itself or by the work environment
* The World Health Organization (WHO), recognizing the impact of “work-related” musculoskeletal diseases, has characterized WMSDs as multifactorial
* We are focusing on the physical component
72
Which provinces are seeing more injuries?
New Brunswick, NWT/Nunavut, PEI
* Ontario has a low injury frequency rate compared to the other provinces. We are the most populous province. Yet we still spend billions on it!
73
The Law and WMSD
* Both Canadian and provincial law in Ontario specifically
* Health and safety legislation that requires employers to protect workers from hazards in the workplace.
* Hazards that can lead to MSD’s – must train ppl to perform job safely. In certain industries this training is mandated on a frequent basis.
* Workers have the right to know about the hazards and to participate in safety processes that can lower these risks (e.g., whimis training).
74
What can cause a WMSD
* The mechanism of WMSDs is thought to be repeated microtrauma at the cellular level
* Repair capacity is exceeded
* ‘WMSD’ is NOT a diagnosis
* Simply a grouping of disorders that typically is caused in the workplace
75
What does WMSD stand for?
Work related musculoskeletal disorder
76
What are the 3 risk factors for WMSD?
1. Physical
2. Individual
3. Psychosocial
All have 2-way arrows
Psychosocial – stress, autonomy, work pace
77
Physical risk factors
* Epidemiological studies have shown that in the presence of known risk factors; the muscles, joints, tendons, blood vessels, and nerves are at risk for musculoskeletal disorders.
* If all these components are high or elevated there is a very high likelihood of a WMSD at some point in time.
* Can’t predict when a WMSD will occur. We all react differently to these microtraumas
78
Cold environments
* Compromises muscle efficiency and may cause vascular and neurological damage.
* May require gloves that have been shown to impact sensation this leading to additional force exertion
* A lot of vasoconstriction which reduces blood flow primarily to the extremities.
Gloves - Might reduce vibration and keep fingers warm there is an instantaneous need to grip harder. Increasing amount of force required to do that occupation.
79
Types of vibration
Whole body vibration (WBV) - mechanical oscillations that are transferred to the body as a whole (in contrast to specific body regions), usually through a supporting platform like a seat.
- 4Hz low back, GI issues
Hand arm vibration (HAV) - manual work involving vibrating power hand tools. HAV is the transfer of vibration from a tool to a worker's hand and arm. The level of HAV is a function of the acceleration level of the tool when grasped by the worker when in use.
- <500 Hz
80
Age and WMSD
* Although WMSD can impact workers at any age, musculoskeletal impairments, particularly of the back, are among the most prevalent occupational problems of middle aged and older (Buckwalter et al., 1993) workers.
* In addition to decreases in musculoskeletal function due to the development of age-related degenerative disorders (i.e., arthritis), loss of muscle fiber and degradation of tissue strength with age may increase the likelihood and severity of soft tissue damage.
81
Sex and WMSD
* Women are three times more likely to have CTS than men (Women.gov, 2011).
* Other reasons for the increased presence of WMSDs in women may be attributed to differences in muscular strength and anthropometry.
* Generally, women are at higher risk of CTS between the ages of 45 and 54
CTS = Carpal tunnel syndrome
82
Strength and WMSD
* Epidemiologic evidence exists for the relationship between back injury and weak back strength in job tasks.
o Chaffin and Park (1973) found a substantial increase in back injury rates in subjects performing jobs requiring strength that was greater or equal to their isometric strength-test values.
o The risk was three times greater in weaker subjects
* Had people do a mid thigh pull. If job requirements were greater than what their mid thigh pull was than they had a greater risk of WSMD’s.
83
Anthropometry and WMSD
* Weight, height, body mass index (BMI) (a ratio of weight to height squared), and obesity have all been identified in studies as potential risk factors for certain WMSDs
o Particularly CTS and lumbar dis herniation
* Vessey et al (1990) found that the risk for CTS among obese women was double that of slender women.
o Increased hydrostatic pressure and fatty tissue throughout the canal.
84
Smoking and WMSD
Smoking is associated with low-back pain, sciatica, or intervertebral herniated disc
- Relationship between smoking and back pain only in those occupations that required physical exertion.
85
Training workers
An important part of a successful ergonomic program is training.
* The training of employees is essential and should include training employees:
o When the job is identified as a hazard
o When employee is assigned to the problem job - Best time!
o Periodically, at least every 3 years
Have a lower risk of WMSD with training
86
Muscles and WMSD's
* Excessively stretching a muscle can lead to a strain
* Obstruction of blood or nerve supply to the muscle can lead to complete deterioration of the muscle
* Exposure to the lack of blood supply
* Not always an acute injury – usually more of a chronic injury
* Muscles can “cramp” based on their inability to remove waste products
* May also exhibit DOMS which is a natural response to abnormal loading
* Stress may lead to an increase in tension, past normal resting zone.
87
Tendons and WMSD's
* Collagen fibers in tendons neither stretch nor contract
* Scar tissue can develop, making tendons more prone to repeated injuries and chronic tension.
* The surfaces on a tendon can become rough
* Tendons can stick, swell and it becomes very painful if not impossible to move certain joints freely.
* Under great amounts of stress and stretch tendons can rupture.
* Inflammation of a tendon can occur when there is not enough synovial fluid in the tendon sheath for lubrication and easy gliding.
* This causes friction between the tendon and its sheath
* These feelings result from an influx of blood
* Influx of blood to the area to try to impair it
* When friction between tendon and sheath see warmth, pressure, tenderness and pain.
88
Nerves and WMSD's
Problem areas:
o Tunnels
o Branches
o Fixed
o Close to unyielding surfaces
Pressure points are okay in the short-term and can lead to problems with blood circulation and nerve compression
* Increased pressure within the body occurs when the position of a body part decreases the size of the opening through which nerves run.
* Nerve compression is primarily caused by pressure from ligaments, tendons, muscles, and bones
o “Pressure points”
89
Nerve %
2% of total body weight but need 20% of oxygen consumption
90
Vascular compression and WMSD
* Occurs when there is a constriction or obstruction of blood flow supply
* Vascular compression can result in ischemia which affects:
o Duration of muscular activities
o Recovery time of a fatigued muscle
* Vasospasm may also occur from vibrations in certain body parts, particularly in the hands and fingers.
* Blood vessels can be affected!
91
Carpal tunnel syndrome (CTS)
* The median nerve is compressed when passing through the bony carpal tunnel (wrist).
* The carpal tunnel comprises eight carpal bones at the wrist arranged in two transverse rows of four bones each.
- Common in office settings
* CTS is associated with forceful and repetitive work
* An increase in pressure in the carpal tunnel can cause CTS if it affects the median nerve or reduces blood supply by compressing capillaries
* Symptoms include; pain, numbness, tingling, burning sensations at the base of the thumb.
* Understand it’s an issue in wrist
- can see issues in pinky and ring finger as well
92
Tendinitis
* When highly repetitive movements are required, the increase in blood supply to the muscles may be associated with decreased blood supply to the tendon
* Tendinitis can result from trauma or excessive use of a joint and can afflict the wrist, elbow, and shoulder joints.
93
Lateral Epicondylitis (Tennis Elbow)
* Overexertion of the extensor muscles of the wrist
* Risk of injury is increased by activities requiring large or prolonged grasping forces
* Combined stressors
* Have the force component, increased activity (compounding issues leading to tennis elbow).
* See this in a lot of industries that require hammering or any type of movement of the elbow that requires high levels of movement and repetition. Seen lots in construction.
* Also see this in office settings. After CTS this is prob #2 of WMSD’s that he came across.
94
Tenosynovitis
enosynovitis is a repetition-induced tendon injury that involves the swelling of tendon sheaths
* The most widely recognized tenosynovitis DeQuervain’s syndrome
* Intersection syndrome is the other most widely recognised tenosynovitis.
* Categorized by issues on lateral side of wrist and base of thumb.
95
DeQuervain’s Syndrome
* Occurs in hand-intensive workplaces.
* Symptoms of these conditions include pain, tingling, swelling, numbness, and discomfort when moving the thumb.
* De Quervain’s is more on the lateral side but pain creeps into base of the thumb
* With intersection pain remains in forearm area.
* Both have the same causes.
* Characterized by pain on the thumb side of the wrist and impaired thumb function
* Activities requiring extensive thumb use are associated with this disorder
* Avoidance of ulnar deviation when operating tools is indicated
96
Trigger finger
* Trigger finger occurs in individual or multiple fingers and results when the tendon thickens or sheath swells
* The finger then gets stuck in a flexed position
o Catches as it runs in and out of the sheath
o Must actively straighten
* Tendon creates inflamed nodule (bump) and as you extend and flex that nodule slips through the sheath and gets stuck.
97
Ischemia
* Ischemia is a condition that occurs when blood supply to a tissue is lacking.
* A common cause of ischemia is compressive force in the palm of the hand.
o Can see purple fingers b/c of it
* If gripping onto something for a long period of time. Vibration and cold can increase the risk.
* Symptoms include numbness, tingling and depending on where it occurs can be some level of fatigue that creeps in as well.
98
Hand Arm Vibration Syndromes
* Vibration syndrome is often referred to as white finger, dead finger, or Raynaud’s disease.
* Excessive exposure to vibrating forces(<500Hz) and cold temperatures may lead to the development of these disorders.
99
Raynaud’s Disease
* Affects blood vessels and nerves of the hands or feet
* If detected early it can be prevented, if not there can be permanent damage
* A drastic reduction in blood supply to the digits.
Issues start to creep in when it’s a chronic exposure over time.
* Need to come up with methods to reduce that exposure – also need buy In from employer.
100
Thoracic Outlet Syndrome
* Compression of nerves (brachial plexus) and/or vessels (subclavian artery and vein) to the upper limb.
Symptoms Include
o Aching pain in the shoulder or arm,
o Heaviness or easy fatigability of the arm
o Numbness and tingling of the outside of the arm or especially the fourth and fifth fingers
o Swelling of the hand or arm accompanied by finger stiffness and coolness or pallor of the hand.
* Work activities such as
o carrying heavy shoulder loads
o pulling shoulders back and down
o reaching above shoulder level
* Can cause the inflammation and swelling of tendons and muscles in the shoulders and upper arms.
* Weak shoulder muscles, long necks and sloped shoulders, poor posture and obesity may contribute to thoracic outlet syndrome.
* Any overhead work for extended periods of time or carrying heavy loads with the shoulder as well.
* Compression occurs in area between neck and shoulder.
101
3 stages of WMSD
Early, intermediate and late
* Although WMSDs are cumulative in nature, the recognition of these disorders varies from person to person.
* The signs and symptoms of musculoskeletal disorders can appear either slowly or suddenly.
102
Stage 1 of WMSD
Early stage
* Workers experience momentary aches and tiredness during normal working hours.
* Symptoms go away on their own overnight and over days off from work.
* Work performance is not affected during this stage, but the symptoms can continue for weeks or even months.
* This is where we hope to catch things – in the early stage
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Stage 2 of WMSD
Intermediate
* Symptoms include tenderness, swelling, weakness, numbness, and pain that begins early in the work shift and does not go away overnight.
* Difficulty sleeping due to the pain and discomfort.
* Reduction in work performance, specifically repetitive work.
o Stage 2 symptoms usually last for months.
* Symptoms are a bit more chronic. Don’t necessarily dissipate with time off work.
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Stage 3 WMSD
Late
* Symptoms include tenderness, swelling, weakness, numbness, and pain that begins early in the work shift and does not go away overnight.
* Difficulty sleeping due to the pain and discomfort.
* Reduction in work performance, specifically repetitive work.
o Stage 2 symptoms usually last for months.
* Symptoms are a bit more chronic. Don’t necessarily dissipate with time off work.
Encourage them to seek medical advice if they haven't already
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How to treat WMSD's
* Restriction of movement (first approach)
- Adjust working postures and workspace
* Application of heat or cold
* Exercise / Rehabilitation
* Medication
* Surgery
