musculoskeletal injuries Flashcards
what is an injury?
- damage to cellular structure of human tissue resulting from application of mechanical stress
what is mechanical stress?
- amount of force acting within a structure
what does stress produce?
strain, which is deformation of a body
what are the three types of stress?
- compression, tension and shear
what is compression stress?
- particles in a structure are pushed against each other
what is tension stress?
- particles pulled away from each other
what is shear stress?
- particles slide relative to each other
what are the 5 types of loading patterns?
- compression, tension, shearing, bending, torsion
what is the compression loading pattern? give an example
- equal and opposite force applied, creates compression stress within structure e.g. nose fracture
what is tension loading pattern? give an example
- equal and opposite forces pull away from each other so tension stress created within structure e.g. ankle sprain
what is shearing loading pattern? give an example
- force applied parallel to structure surface, creates shear stress within structure e.g. blisters
what is bending loading pattern? give an example
- compression on shortened side, tension to lengthened side and stress across centre e.g. Achilles tendon injury
what is torsion loading pattern? give an example
- twisting about an axis so induces sheer, compression and tension stresses e.g. anterior cruciate ligament injury
what is acute traumatic injury? what trauma does it cause?
- results from single episode of stress, exceeding a tissue’s tolerance
- causes macrotrauma
what is chronic overuse injury? what trauma does it create?
- results from repetitive application of stress at levels less than a tissue’s tolerance
- causes microtrauma
what does potential for tissue damage depend on? (3)
- magnitude of stresses
- total number of stress peaks
- interval between stresses
describe an overuse injury
increased activity causes increased tissue stress resulting in microscopic tears; if tissue remodelling is lower than rate of damage the tissue breaks down
can overuse be beneficial?
yes, if the tissue remodelling exceeds rate of damage then stronger tissue is created
what are ligament injuries?
- acute= sprain
- overuse is uncommon
describe sprain and give an example
- caused by sudden over stretch with joint in extreme position
- contact e.g. rugby
- non- contact e.g. ACL
how do you grade ligament sprains?
- microscopic tearing
- partial disruption
- complete rupture
what are muscle injuries?
acute = strain
no overuse
what is a strain?
- occurs from forceful overstretch, forceful eccentric contraction or a combination
how do you grade muscle strains?
grade I = microscopic tearing
grade II= partial disruption
grade III= complete rupture
what are bone injuries?
acute= fractures
chronic= stress fracture
what is a fracture?
- break in structural continuity of bone caused by sudden and excessive force
how easy is it to break a bone?
- healthy bone requires alot of force
what is a stress fracture ?
- caused by increased activity e.g. running so microscopic tears occur; if body’s remodelling rate isn’t fast enough
what is an example of a stress injury into a stress fracture?
microfractures to small cortical fracture
what are common stress fractures?
- runner (tibia), metatarsals of ballet dancers, ribs of golfers, lower back of fast bowlers, army recruits
how does overuse affect acute injury?
- if you have an overuse injury an acute injury is likely due to tissue weakening
what are the high risk stress fractures?
- femoral neck
- middle anterior tibia
what are tendon injuries?
- acute= rupture
- chronic= tendinopathy
describe tendinopathy
- collagen degeneration and disorientation e.g.. tennis elbow, jumpers knee
how does age affect degeneration of collagen?
- older you get means the more degeneration
