KIN 428 Flashcards
Definition of (neuro)musculoskeletal disorders?
Injuries and disorders of the muscles, nerves, tendons, and ligaments, joints, cartilage, bones, and spinal discs
MSD?
musculoskeletal disorder
WMSD?
Work-related musculoskeletal disorder
UEMSD
upper extremeity musculoskeletal disorder
CTD
cumulative trauma disorder
CTS
carpal tunnel syndrome
Estimated cost for overall MSD?
$254 billion in USA and $25 billion in Canada
Percentage of all claims to WSIB are from the upper extremity?
Approx. 30%, with the finger causing the most issues
Wide variation in estimates of specific UEMSD prevalence is due to?
Recording/reporting of injuries, definition of a disorder, and the population being studied
Prevalence vs. Incidence?
Prevalence is the portion of the population that already has the disorder/disease. Incidence is the portion of the population that newly has the disorder/disease.
What are the fastest growing cause of occupational disability?
UEMSD, especially the shoulder because they have the longest return to work (approx 45 days) because they are cumulative not traumatic injuries.
Students and MSD, who is protected and who is more at risk?
Protective: being a history major or an athlete. Risk: computer use greater than 20 hours per week, being a computer science major, and being female!
Percentage of GDP that is spent on MSds?
3.4-5%
Tissue types for UEDs?
tendon, ligament, muscle, nerve, vascular, bursa, cartilage, bone, other connective tissue (i.e. labrum)
Itis?
Inflammation
Syndrome?
Usually neural
Some examples of nerve disorders in the UE?
thoracic outlet syndrome, digital neuritis (bowler’s thumb),
Some exaples of tendon disorders in the UE?
Rotator cuff tendinitis, flexor tendinitis, ganglionic cyst
Some examples of muscle disorder in UE?
Focal dystonia, tension nexk syndrome
Some examples of vascular disorders in UE?
White finger, Raynaud’s syndrome
Role of the tendon?
Transmit forces from muscles to bones
Tenosynovitis?
Inflammation of the tendon and the tendon sheath. Really bad because the more that swells the more compression there is, increasing chances of nerve problems
Tendinitis?
Inflammation of JUST the tendon
Enthesopathy?
insertional tendonsitis…occurs at bond-tendon junction
Peritendinitis?
Central portion of the tendon, usually NOT the sheath
Myotendinitis?
Muscle-tendon interface inflammation
Examples of tendon disordrers?
Bicipital tendinitis (often common with rotator cuff injuries), lateral epicondylisis, trigger finger (debated if it is tendoninitis or tenosynovitis b/c there may be stenosis of tendon sheath)
3 mechanisms of tendon disorder development?
- Excessive and typically repetitive TENSILE loading 2. Compression 3. Tendon strength decreases with age
What does excessive and repetitive tensile loading do to a tendon?
Leads to an increase in capillaries (need more blood to enhance healing), inflammation (immune response), edema (bruising), microtears (stack enough of these = total tear), and fibre separation
What type of force on the tendon causes the most damage?
Transverse/compression because the collagen is not aligned in a way that it can handle forces perpendicular to it (like fibre optic cables)
Muscle function?
Initiate movement, generate force, stabilize joints, highly vascular and bring blood supply to the tendon. Actuators for the lever system of the skeleton.
Myalgia?
Muscle soreness and pain (local tenderness to touch)
Myositis?
Inflammation of muscle tissue
Myofascial pain syndrome?
Chronic myalgia, usually related to insufficient recovery (doing the same job over and over again)
Fibromyalgia/fibrositis?
End stage of myalgia…spastic muscles, tingle (nerve commponent), nervousness, sleeplessness.
Why does MSK pain increase at night?
Not distracted by the day’s activities anymore, so people concentrate on their pain.
Examples of muscle disorders?
Tension-neck syndrome (people at poor work stations, common in clerical professions, hunched shoulders). Writer’s cramp (focal dystonia, overgrip between 5-10x the required force). CTS and finger force are related.
Mechanisms of muscle disorder development?
External force on passive tissues…stretch in eccentric contractions. L-T relationship…stretching passive tissues then putting load on top of that, leads to sarcomere strain, but recovery is fast (slows with age)
Nerve function?
Send signals through the body (commands and feeback are used to assess after an injury)
What is nerve entrapment?
Nerve trapped between 2 tissues (muscle, bones, connective tissues)
What does nerve entrapment cause?
Impaired blood flow, which decreases oxygen to a tissue, leading to tissue death. Entrapment can also cause the mechanical blocking of depolarizations, which leads to atrophy
Double crush syndrome?
The existence of 1 entrapment increases the likelihood of another axonal flow disruption…nerves can be greater than 1 metre long, so lots of opportunities to get crushed along the way…CTS surgery when the problem is actually at the elbow
Digital neuritis?
Nerve inflammation due to direct pressure in fungers and thinb
Examples in UE nerve disorders and the nerve affected?
CTS (median verve), Cubital Tunnel Syndrome (ulnar), Pronator Teres Sydrome (median nerve), Thoracic Outlet Syndrome (Brachial Plexus), Bowlers Thumb (exmaple of digital neuritis…direct pressure of bowling bowl on ulnar nerve in the thumb0
Mechanisms of nerve disorder development?
- Compression of the nerve 2. Vibration accelerates the process through a series of microdamages to the nerve 3. Direct compression leads to intraneural edema (bruising) and fibrosis
What does compression to a nerve cause?
It causes damage, which leads to an inflammatory response, fibrin deposits are laid in an attempt to heal the nerve, leading to fibrous tissue, which leads to more compression, and eventually axonal degeneration.
Role of vasculature?
Provides materials to cells for normal functions…especially O2
Ischemia?
Decrease in blood flow to a body part caused by obstruction or constriction of blood vessels
When is ischemia of greatest concern?
During fractures…if the bone fragment dies, the doctors must digure out hoe to reconstruct bone without the dead piece (huge problem with the femoral and humeral head)
Examples of vascular disorders in the UE?
- Hand-Arm Vibration Syndrome (HAVS) 2. Raynaud’s Syndrome/White Finger 3. Hypothenar Hammer Syndrome (ulnar artery)
Precipitating factors for vascular disorders?
- Vibration 2. Cold temperatures 3. Direct Pressure
Definition of bursa?
Sack of sack-like body cavity that usually contains synovial fluid and is usually around joints (articulations) and “exposed” bones. Role is to reduce friction focal forces and distribute them
Bursitis?
Inflammation of the bursa
Causes of bursitis?
- Friction (cartilage degraded, then bone on bone happens, and so do bone chips) 2. Trauma 3. Inflammatory Disease (rheumatoid arthritis) 4. Bacterial infections
Bursitis locations in the UE?
Elbow (exposed bone) and shoulder (sub-acromial…inflamed bursa = impinges supraspiantus tendon)
Role of the bone?
- Form and protection 2. Factory for RBCs and Ca2+ storage 3. Attachment for muscles and form articulating joints for movement
Role of articular cartilage?
- Cushioning for joints 2. Support 3. Shock absoprtion/distribution (decreases stress risers)
Arthritis?
Joint inflammation…leads to pain, swelling, and stiffness (inability to move a joint)
Rheumatoid arthritis?
Subclass of arthritis that involves general/systemic imflammation throughout the body
Gout?
Specialized case of rheumatoid arthritis
Osteoarthritis?
most common arthritis…cartilage degeneration at a specific joint
Fractures?
Usually traumatic with the exception of stress fractures, which is due to the incomplete healing of microfractures
Age-related skeletal changes?
- Geometric (alter the mechanical properties, particularly load tolerance…causes more fractures) 2. Cortical (decrease in thickness and increase in porosity) 3. Trabecular (decrease in thickness and in number of trabeculau, making it easier to fracture the bone because of the loss of the ability to distribute and absorb force)
Why are older people very susceptible to crush fractures in the vertebrae?
Body keeps the bones it needs to support common forces and movements…most forces on the spine are vertical, so the most bone is left in a vertical fashion, making the vertebrae weakened to horizontal forces
What is the worst age range for bone loss in women?
50-80…menopause
Why do women age 50-60 present with more wrist fractures than hip fractures?
Women in this age group have longer strides and are moving faster than women 75+, so when they fall, they fall forwards, using their wrist to brace the fall. Women 75+ have smaller base of support due to small steps and slow gait, so when they fall, they fall backwards and fracture a hip.
What is the leading cause of disability over the age of 65?
Osteoarthritis
What is osteoarthritis?
Cartilage degeneration that is caused by the reduction in synthesis of cartilage matrix, which leads to bone on bone contact. This then decreases range of motion, which leads to compensations in movements. These compensations leads to bone spurs, which cause pain, and result in even more compensations, more bones spurs, etc…vicious cycle!!
What percentage of long-term disability in Canada is a result of arthritis?
25%…90% have dec. mobility, 66.6% have stair trouble, 62.7% cannot stand for extended periods of time, 51% have trouble picking things up from the floor, and 17.4% cannot dress themselves
Osteomalacia?
Demineralization of bones, which leads to deformities and fractures…usually linked to a vitamin D deficiency
Paget’s Disease?
Excessive bone resorption and overvascularized bones, which leads to brittle bones. This is a major cause of spinal compression fractures because trabecular bones is the first to be lost (soda can crushing analogy)
Age impact on connective tissue?
- General loss of elasticity with age, which comes along with increased stiffness, brittle tendons, and decreased regeneration capacity. This causes increased pathology of tendon tears because brittle tendons can tolerate even less transverse/compressive loads.
Physiological age related muscular changes?
- 20-40% decrease in muscular strength with age 2. Fibre de-inervation (leads to atrophy and increased MU recruitment for the same task, so increased fatigue) 3. Decrease the number of fibres 4. Fibre type composition changes (increase in percentage of Type I fibres, so more endurance, but cannot do things with intensity of speed) 5. Decrease in speed of contraction
When does the precipitous drop-off in muscle strength occur?
At about age 50…this is a problem because the average working age is 50, so people are expected to do the same type of work, but they now have decreased abilities…not good)
Anatomic age related muscular changes?
Loss of lean muscle tissue (i.e. muscle wasting)
Histochemical age related muscular changes?
Type II fibre atrophy, so % of Type I fibres increases. Loss of elasticity…decreases passive response, so must use more muscle to get things dones because force is from active and passive, but you now have less muscle fibres, so notgood…
Age related muscular pathologies?
Muscle cramping, myasthenia gravis, sarcopenia
What causes increased muscle cramping in older people?
Electrolyte imbalances caused by dehydration (neural drive for thirst decreases with age) AND spinal neuronal irritation
Myasthenia gravis?
Muscles become high fatiguable due to a defect in impulse transmission…antibodies block Ach receptors
Sarcopenia?
Gradual muscle loss tied to neural deficits
Age-related neural changes?
- Loss of neurons (mostly large neurons that are used for gross motor control, but also small neurons that control fine motor skills) 2. Action Potential Speed Reduction, which leads to a decrease in muscle contraction, and therefore force production. It is linked to vascular compromise (blood supply to nerve is lessened, leading to nerve death) 3. Homeostasis maintenance degrades (maintaining dopamine levels, causing motor tremors)
Age-related neural pathologies?
- Stroke 2. Dementia 3. Parkinson’s