Mechanisms of Injury (MOI) & Injury Classification Flashcards
Define trauma
a physical injury or wound that is produced by an external or internal force
define mechanical injury
when a force applied to any body part results in a harmful disturbance in function/structure
define MOI
how it happened
-the method by which trauma and its associated forces directly or indirectly impacts the body
how do mechanical injuries happen
from force that changes the state of the rest
name 8 types of MOI’s
-all out exertion
-contact
-striking or throwing projectiles
-propulsion of body through air
-repitition of movement
-speed of the sport
-extended periods of time/ duration of activity
-large number of participants in small area
6 factors affecting likelihood of injury
-size/magnitude of force
-forces moment arm (determines the amount of torque)
-direction the force is applied (compression vs sheering)
-material properties of the tissue affected
-area over the force is applied
-magnitude of stress produced by the force
3 classifications of trauma
-bacterial/viral
-chemical
-mechanical
what includes bacterial/viral trauma
-systemic problems
-musculoskeletal type pain manifestations
-flu/cold/shingles/kidney infections
what includes chemical trauma
-chronic pain
-diabetes
-autoimmune illness (MS)
what includes mechanical trauma
-sprains/strains
-fractures
define load
an external force acting on the body causing internal reactions within the tissues
define stiffness
ability of a tissue to resist a load
(increase in stiffness=the larger the magnitude load can resist). Can return to normal following deformation.
define stress
internal resistence to a load
define strain
internal change in tissue (length) resulting in deformation (change in shape of tissue)
define yield point
when tissue is deformed to the extent that it no longer reacts elastically
define direct impact
-injury occurs at the point of impact (contact)
define indirect impact
-injury occurs at a point away from the point of impact (non contact)
what are the 5 type of tissue stresses/tissue loading
- tension
- compression
- shearing
- bending
- torsion
define tissue stress: Tension & what happens
- force that pulls/stretches a tissue
-muscle strains and ligament. Muscle pulled at both origin & insertion.
-sprains both occur with increased tension
define tissue stress: Compression & what happens
-produced by an external load applied towards one another on opposite surface in opposite directions
-2 things being pushed together
-both shortens & widens a structure
-when force can no longer be absorbed.
define tissue stress: Bending & what happens
-when 2 force pairs act at opposite surfaces forcing those surfaces to move in parallel directions relative to once another.
- works with compression (concave side) & tension (convex side).
define axial load for bending
axial load is the compression force (coming from the top and bottom)
define the 3 point load in bending
2 forces on convex side (lateral), 1 force on concave side (medial)
define 4 point load in bending
2 forces on convex side (lateral)
2 forces on concave side (medial)
define tissue stress: torsion & what happens
application of the torque about the long axis of a structure (long bone) can cause twisting of the structure
- max shear occurs in planes that are perpindicular
-happens in long bones/bones that twist on itself (twist and slide) ex. ACL tears
define overuse
injury occur with repetitive dynamics
(ex). repetitive/constant stresses, microtrauma. Running, jumping, throwing
what does traumatic injuries have that over use injuries do not have (2)
Over use injuries do not have
1. MOI
2. non contact
Name 8 overuse injuries and their associated load
- muscle cramps (tension/compression)
- muscle soreness (tension)
- tendinitis/tendonosis (tension)
- tenosynovitis (tension)
- OA (compression/sheer/torsion)
- Capsulitis/synovitis (tension/compression/shear/torsion)
- stress fracture (tension/compression/shear/bending)
- Neuritis (Compression/tension/shear)
name 6 traumatic injuries & their associated load
- muscle strains (tension/torsion/shear)
- contusions (compression)
- Ligament sprains (tension/torsion/bending)
- dislocations/subluxations (tension/torsion/ shear)
- Bone fracture (tension/compression/shear/torsion/bending)
- Neuropraxia (compression/shear)
what are the 4 injuries that are considered both overuse & traumatic, plus their loads
- myofascial trigger points (tension)
- Bursitis (compression/shear)
- Epiphyseal injury (tension/compression/shear/torsion/bending)
- Apophyseal injury (tension/compression/shear/torsion/bending)
define muscle strain & how the injury occurs (2)
-a stretch, tear, or rip in the muscle or its tendon/too quick contraction
1. overstretched by tension
2. forced to contract against too much resistance
2 locations muscle strain can occur
- muscle belly
- near the tendon junction
describe 1st degree muscle strain
< tears to muscle fascicle & bundle
-mild weakness, swelling & loss of function
-pain when contracting & stretching
-decrease in ROM, not palpable
describe 2nd degree muscle strain
> tears to muscle fascicle/bundle
- mod./severe weakness & swelling & loss of function
-pain in contracting & stretching
-decreased ROM & not palpable
describe 3rd degree muscle strain
-most of all muscle fibers ruptured
- mod./severe weakness/swelling & loss of function
-none-mild pain while contracting and stretching
- palpable if done early
-no surgery needed, but long rehab
define muscle cramps, how they occur & what its related to (3)
-painful involuntary MSK contraction
-Occurs in well developed individuals when muscle is in shortened position
Thought to be related to:
1. excessive water loss
2. electrolyte imbalance
3. strength imbalance
define muscle guarding & how to help
-muscle contraction in response to pain
-following an injury, muscles within an effected area contract to splint the area (<pain though limitation of motion)
-Heat will help relax the muscle
Define muscle spasms and explain the 2 types.
-A reflex in the muscle caused by trauma of the MSK system
1. Clonic- alternating involuntary muscular contractions and relaxations in quick succession
2. Tonic- rigid contractions that last a period of time
Define tendinopathy
broad term encompassing painful conditions occurring in and around tendons in response to overuse
what 2 terms are included in tendinopathy
- tendinitis
- tendinosis
define tendinitis & tendinosis & their causes
- tendinitis- inflammation of the tendon
- Tendinosis- breakdown of tendon without inflammation
-caused by a particular movement that is performed repeated (overuse)
-the repeated movement causes irritation when the tendon is sliding in relation to nearby structures
difference between tendinosis & tendinitis plus treatment
tendinosis- gradual onset, with diffuse tenderness due to repeated microtrauma and degenerative changes
Tendinitis- Obvious swelling and pain
treatment in acute phase- rest
- define tenosynovitis, 2. characteristics of acute and chronic, and 3. where it often occurs
- Inflammation of synovial sheath of the tendon
- Acute- rapid onset, crepitus, and diffuse swelling
chronic- thickening of tendon with pain and crepitus - long flexor tendon of the digits & bicep tendon
- define contusions and its 2. major complication
- injury that results from a sudden traumatic external blow that compresses the soft /boney tissue (bruise)
- myositis ossification
define myositis ossification
if the area where the contusion is has been subjected to repeated blows, small calcium deposits may begin to accumulate in the injured area which can build up to produce a spur which will significantly impair movement (bone grows in the muscle tissue)
describe 1st degree contusion (tissue damage, weakness, muscle spasm, ecchymosis, ROM, loss of function)
tissue damage: superficial tissues are crushed
weakness: none
muscle spasm: none
ecchymosis & swelling: mild
ROM: no restriction
loss of function: mild
describe 2nd degree contusion (tissue damage, weakness, muscle spasm, ecchymosis, ROM, loss of function)
tissue damage: superficial & deep tissues are crushed
weakness: mild/moderate
muscle spasm: none
ecchymosis & swelling: moderate
ROM: decreased
Loss of function: moderate
describe 3rd degree contusion (tissue damage, weakness, muscle spasm, ecchymosis, ROM, loss of function)
damage tissue: deep tissue is crushed
weakness: moderate/severe
muscle spasm: possible
ecchymosis& swelling: severe
ROM: significantly decreased
loss of function: severe
- Ligament sprains definition 2. what it involves
- what happens once a ligament has been stretched
- when a stress is applied to a joint that forces motion beyond its normal limits
- involves stretching/tearing of ligaments
- once a ligament has been stretched aelastic scar forms, preventing ligament from regaining its original tension
1st degree ligament sprain (damage to ligament, distraction, weakness, muscle spasm, loss of function, pain with stretching, ROM)
damage: few fibers of ligament torn
distraction: <5mm
weakness: mild
muscle spasm: none
loss of function: mild
pain with stretching: yes
ROM: decreased
2nd degree ligament sprain (damage to ligament, distraction, weakness, muscle spasm, loss of function, pain with stretching, ROM)
damage: nearly 1/2 fibers torn
distraction: 5-10mm
weakness: mild to moderate
muscle spasm: none
loss of function: moderate/severe
pain with stretching: yes
ROM: decreased with swelling, dislocation or subluxation is possible
3rd degree ligament sprain (damage to ligament, distraction, weakness, muscle spasm, loss of function, pain with stretching, ROM)
damage: all ligament fibers are torn
distraction: >10mm
weakness: mild to moderate
muscle spasm: none to minor
pain with stretching: no
range of motion: may increase or decrease depending on swelling, dislocation & subluxation is possible
- define dislocation, 2. most common places, 3. other injuries from dislocations
- a bone is forced out of alignment and stays out until surgically/manually replaced
- shoulder, elbow, fingers, knee
- Likely result in a rupture or partial rupture of stabilizing ligaments. First dislocation should be considered and treated for possible fracture. Deformity is present
- define subluxation, 2. surgical intervention? 3. other injuries caused from it
- brief, transient injury involving partial dislocation & spontaneous joint relocation
- possible surgical intervention needed due to other possible injuries associated
- can result in rupture of stabilizing joint ligaments, blood supply & nerves when it went back in. No deformity present.
- define impingement, 2. how it is caused, 3. where it often occurs
- pinching of intervening tissue between 2 boney structures
- overuse injury/muscular imbalance between chest & back
- occurs with tendons or bursa in joints with high amounts of ROM (hips/shoulders)
- Define friction injury, 2. what can it cause
- occurs with repetitive rubbing between 2 structures or an intervening structure (bursa)
- can cause debilitating chronic pain
describe the 2 types of fractures
closed fracture: little or no movement or displacement of the broken bones
open: enough displacement of the fractured ends that the bone actually breaks through the surrounding tissues, including skin
types of fractures (11)
simple
compound
depressed
transverse
comminuted
oblique
epiphyseal
spiral
greenstick
avulsion
impacted
describe division of labour
each MSK structure participates in the division of labour in absorbing the impact generated energy
-if one link in the chain fails to do its share, the others must pick up the load (compensation)
describe foot to head directed impact
-point of contact is distal at the foot
-energy is transmitted through the large bones of the legs and pelvis first & the impact is dissipated by the time it reaches the spine
-minimizes injury
how does foot to head directed impact minimize injury
-dissipates impact through larger bones
-distal(head) to proximal (body) trauma has greater incidence of injury with the cervical spine, the c-spine tolerates the least amount of weight/force
what happens when forces act (2)
- acceleration or change in velocity
- deformation or change in shape
(ex) when a tennis ball its the raquet, the ball is accelerated & deformed
- define imbalances, 2. what can cause them 3. what happens if not corrected
- unilateral muscle or boney & soft tissue asymmetries
- sport activities may cause aysmmetries to develop
- poor pathomechanics, can become chronic & more prone to injury
4 determinants of severity of injury
- low magnitude/long duration
- high magnitude/ short duration
- low magnitude/low duration
- high magnitude/long duration
describe low magnitude/long duration with examples
low energy impact/long duration impact time. Tissue threshold could be exceeded over time
(ex) over use injury, blister, callous, stress fracture
describe high magnitude/short duration with examples
high energy impact/short duration time. Impact threshold of weaker structures may be exceeded
(ex) sprains and strains
describe low magnitude/short duration and examples
low energy/short duration of contact time. Impact threshold is not exceeded, potential for injury is low
(ex) minor contusions
describe high magnitude/long duration and examples
high energy of impact/long duration of contact time. Greatest potential for injury and to all structures involved
(ex) fractures, dislocations, ligament injuries
describe simple (closed) fracture
bone breaks cleanly but ends do not break the skin
describe a compound (open) fracture
bone breaks and penetrates through tissue and skin
describe depressed fracture
occurs on flat bones (skull) when the broken portions driven inward
describe transverse fracture
breaks occurs in straight line across the bone
describe comminuted fracture
bone fragments into several pieces
describe oblique fracture
breaks occurs diagonally when torsion occurs on one end while the other is fixed
describe epiphyseal fracture
separation involves the epiphysis of the bone
describe spiral fracture
jagged bone ends are S-shaped when excessive torsion is applied to a fixed bone
describe greenstick fracture
bone breaks incompletely
describe avulsion fracture
bone fragment is pulled off by an attatched tendon or ligament
describe impacted fracture
bone is impacted or driven into another piece of bone
