Week 2 - Work Related Musculoskeletal Disorders (WRMSD) Flashcards
(53 cards)
1
Q
Define: WRMSIs
A
work related musculoskeletal injuries
- activity related disorders that affect muscles, tendons and other soft tissues (nerves or arteries) developed as a result of work related activities
2
Q
List different types of WRMSIs (7)
A
- Tendinitis: inflammation of the tendon
• Tenosynovitis: inflammation of the tendon sheath
• Stenosing Tenovaginitis “Trigger Finger”
• DeQuervain’s disease: inflammation of the thumb
• Carpal Tunnel Syndrome
• Vibration White Finger:
• Neck /back pain
3
Q
Fill in the blank: WRMSIs make up ___ of WCB costs
A
33%
4
Q
Fill in the blank: __ of the working population experiences symptoms at least __ per year
A
- 50%
- 1
5
Q
__ workers report back pain for at least one week over the previous 12 months worked
A
20%
6
Q
__ reported hand pain from work
A
17%
7
Q
estimated cost to _____ / year in medical costs and lost days to Canadian economy
A
$3 billion
8
Q
CTDS: ASTD: O/E: RSI: OOI:
A
CTDS: cumulative trauma disorders Accustomed soft tissue disorders (ASTD) O/E: over exertion RSI: repetitive strain injury OOI: occupational overuse injury
9
Q
Major industries affected in BC by WRMSIs (7)
A
- Health Industry
- Retail
- Forest Industry
- Office Environments
- Mining
- Construction
- Food Processing
10
Q
10 Characteristics of WRMSIs
A
- Effect muscles, tendons, nerves or vascular system
- Are beginning to plateau in the workplace
- Mechanical and physiological process
- Related to work duration and intensity
- Requires weeks, months or years to develop
- Requires weeks, months or years to recover; little is known about the recovery process
- Poorly localized, non-specific and episodic
- Often unreported
- Multiple work and personal causes, the interaction of which is poorly understood
- Repair leaves tissue stronger and more suited to the task (adaptation)
11
Q
When muscle is injured, it is often at the _____. Why?
A
myotendinous junction
- concentration of force (where most of the force is) and there is less elasticity
12
Q
contusion
A
bruise
13
Q
avulsion
A
rupture
14
Q
MVC
A
MVC = maximum voluntary contraction up to 15% or up to 5% for static contractions will result in muscle fatigue if sustained for a full work day 8 hours
15
Q
Tendon and ligaments:
- tendon
- ligament
- function of both (2)
A
Matrix of ground substance, cells and mix of collagen and elastin
- tendon: muscle-bone
- ligament: bone-bone
- fibrous connector for soft tissues
transmitting mechanical forces (tension) - highway for blood vessels & nerves
16
Q
Collagen
A
High tensile strength, resists elongation
17
Q
Elastin
A
Low tensile strength, deforms greatly
18
Q
Sprain
A
injury to ligament
19
Q
Joint capsule
A
sheet of collagen fibres, proteoglycans and elastic fibres surrounding joint
20
Q
What does it mean when the synovial fluid is described as a thixotropic lubricant?
A
rapid motion, low viscosity; slow motion, high viscosity
21
Q
What are 3 ways sensory and motor nerves can be injured?
A
- compression
- tension
- severed
22
Q
Occupational Biomechanics
A
“the study of motion and forces in the human body due to the interaction of workers with their tools, machines and environment.”
Chaffin, 2016
- Allows understanding of loading on the body
- Assists in understanding of WRMSI mechanisms
- Provides guidance for solutions
23
Q
Cumulative load equation
A
Cumulative load = load x time x repetitions
24
Q
Repeated or sustained loading results in _______
A
a reduced threshold stress (stress at which failure occurs)
25
Cumulative laod theory of injury/ Material fatigue concept
– wear and tear balanced by self repair (stress-recovery)
26
Physiological changes due to WRMSIs
* Inflammation and swelling
* Stimulate nocioceptors (pain)
* Increased muscle tension to reduce motion • Increased synovial fluid in tendon sheath
* Chronic joint pain
27
Specific hand/wrist anatomy
```
Flexors inserts on medial epicondyle
Extensors insert on lateral epicondyle
Abduction
Anatomical snuff box
Brachial plexus, median nerve, ulnar nerve, radial nerve
Radial nerve: everything on thumb side
Transverse carpal ligament
```
28
Tendinitis
Tenosynovitis
- signs and symptoms
- Tendinitis: inflammation of the tendon
- Tenosynovitis: inflammation of the tendon sheath
Across the radiocarpal joint
- Ssx: Swelling, pain, crepitus on passive motion, local tenderness, pain increased by resistive motions
= Signs: Palpable tendon nodule, inflammatory signs, palpable tendon nodule that is point tender, Vascular disruption, hematoma, Pronounced asymmetric grip strength (4kg)
29
Stenosing tenovaginitis
| - signs and symptoms
- Fibrous thickening of the tendon sheath in the flexor tendons of the hand
- Symptoms:
Results in snapping movement of finger due to swelling and restricted gliding of the tendon
“Locking usually occurs” during flexion/extension
- Signs: nodule present on tendon
- Stenosing: stopping
30
DeQuervain's disease
| - signs and symptoms
DeQuervain’s disease: Fibrous thickening of the tendon sheath in the flexor tendons of the thumb
Symptom: pain in the anatomical snuffbox with possible radiation up forearm
Positive Finkelstein test (passive ulnar deviation - positive = pain)
31
Carpal Tunnel Syndrome
| - signs and symptoms
- Entrapment or injury of the median nerve in the carpal tunnel (formed by the transverse carpal ligament and carpal bones); Result of edema in tissues around the tunnel; impingement of the median nerve due to swelling (pregnancy can cause this, diabetes)
- Symptoms: Pain, numbness, or tingling in the median nerve distribution of hand and fingers, atrophy or decreased strength if motor branch is involved
- Symptoms: Nocturnal exacerbation
- Sign: Increased compression in tunnel (normal 3mmHg); Reduced nerve conduction velocity (normal 45-75 m/sec)
32
What are 2 tests that would be positive if you had carpal tunnel syndrome
- Phalen's test
| - Tinel's sign
33
Raynaud’s Disease
some areas of your body — such as your fingers and toes — feel numb and cold in response to cold temperatures or stress genetics
34
Vibration White Finger
- vascular disturbance of fingers due to exposure to vibrating frequency (using handheld power tools); balancing of extremities
- Severe cases can be occlusion and tissue atrophy
35
Epicondylitis
- Tenderness at lateral epicondyle
- Pain upon gripping
- Decreased grip strength
- Increased pain with wrist flexion
36
Medial epicondylitis
- Medial Epicondylitis: Tendinitis of the common flexor origin, including pronator teres
- Tendinitis of the common flexor origin, including pronator teres
37
Describe the pros and cons of the shoulder
- mobility at expense of stability; ball and socket joint
38
Shoulder tendinitis
Inflammation or degeneration of the tendons of the rotator cuff or biceps
- Inflammation or degeneration of the tendons of the rotator cuff or biceps
- Painful arc, more apparent on active restricted movement than passive
- Nocturnal symptoms,
- Crepitus
- Subacromial tenderness
- Referred pain along C5 distribution
- Pain in anterior shoulder which increases with abduction
- positive Speed's test and Yergason's
39
Describe: Speed's test
resisted elbow flexion: pain in long head of biceps
40
Describe Yergason's test
Resisted supination: pain in long head of biceps
41
Bursitis
- Inflammation of the bursa sac in the joint
- Small fluid-filled sacs in joint
- Cushion pressure points between bone and tendon
42
Thoracic outlet syndrome
- Neurovasular disturbances caused by compression of the neurovascular bundle at the thoracic outlet; can also be caused by Fibrous bands/ or extra cervical rib (malformations)
- Wide variety of symptoms depending on compression
• Pain in fingers
• Numbness in fingers
• Weak pulse at wrist
• Vascular forms are rare: s/s blanching, cold extremities
- Roos test - pain,heaviness or profound arm weakness or numbness and tingling of the hand
- Allen test - radial pulse is palpated and if it disappears as the patient’s head is rotated the test is considered positive.
43
Risk Factors cited in Literature
```
• Personal Factors
• Repetition
• Force
• Awkward Postures
- Duration
• Vibration
• Cold
• ContactStresses
• Psychosocial Issues
```
44
Personal factors (7)
* Age (wound healing slows with age)
* Moderate to heavy smoking
* Previous similar history
* Inflammatory disorders (arthritis)
* Pregnancy (for CTS)
* Diabetes mellitus
* Body Mass Index (BMI)
45
Describe repetition as a risk factor
- Refers to a series of motions performed over and over again by the same muscle groups
• Expressed as movement or exertions/time
• Macro and microtrauma as a result of tendon deformation
- Cycle time less than 30 sec. and/or
• 50% of cycle time involved in same motion pattern
46
Factors affecting force
```
Force
Lever arm (torque)
• Internal vs external load
• Force velocity
• Strength-endurance
• Rest time
• Tolerance of tissue
• Grip type
• Posture
• Grip size
• Gloves
```
47
Force guidelines
- Reduce required force
- Exertion >60%MVC avoided
- Greater than 4Kg grip force increases risk
- Greater than 2kg pinch grip increases risk
- Decrease the lever arm and consider mechanical advantage Reduce velocity
- Reduce endurance
- Frequent action up to 30% MVC
- Continuous action up to 15% MVC
- Sustained static exertions greater than 5% MVC problematic
48
Awkward Postures
```
Flexion
Extension
Radial deviation
Ulnar deviation
Pronation
supination
```
* increase internal load on tendons
* increase pressure in carpal tunnel
* increased friction over bones
49
Which wrist posture has the smallest safe angle
radial deviation - <10 degrees
50
Contact stresses
- Mechanical tissue stresses produced in the area of contact with external object
- Some evidence for CTS and digital neuritis
51
Vibration
mechanism - occlusion of blood vessels
- 15 to 800m/sec2 and frequencies of 8 to 500Hz are of concern
- Are exposure limits set by ISO
52
Cold
- Appears to be related to reduced tactile sensation (same mechanisms as gloves) creating increased force
- External temperature, compressed air, or conductive cold
53
Psychosocial Issues
- Contribute to etiology of disorders, Influence whether workers report injuries, Success of rehabilitation or return to work programs
