Musculoskeletal injury Flashcards
What are the two most common types of muscle injuries?
Contusions and strain-induced
What causes contusions?
crush or compressive
what causes strain-induced injuries?
tensile (stretching)
what causes a laceration?
a cut
what are the muscle groups commonly affected by muscle injuries?
hamstrings, adductors, quadriceps, and calf muscles
which muscles are vulnerable to crush injuries?
the quadriceps
what is the MOI of a crush injury?
a direct blow (blunt force)
if the muscle is tensed with a crush injury is the force more superficial or deep?
superficial
what is formed with a crush injury?
a hematoma
could myositis ossificans occur with a crush injury?
yes
what is myositis ossificans traumatica?
heterotypic bone formation (bone starts growing into the muscle)
what is intramuscular myositis ossificans traumatica?
abnormal bone growth in one muscle
what is intermuscular myositis ossificans traumatica?
abnormal bone growth in multiple muscles
what determines if myositis ossificans traumatica is intramuscular or intermuscular?
how deep the force is
could the abnormal bone growth go away with time?
yes
what causes a mild (micro traumatic) strain-induced injury?
eccentric over-loading, or overexerting an untrained muscle
what is mild strain-induced injuries?
soreness after new activity; minor muscle damage with delayed-onset muscle soreness (DOMS)
what causes severe (macro traumatic) strain-induced injuries?
a rupture of muscle fibers, connective tissue, and blood vessels.
typically from overexerting the muscle quickly and stopping quickly
where is severe strain-induced injuries the most common?
and the mho-tendinous junctions (where the tendon meshes with muscle)
what happens when muscle is injured?
there is damage to connective and muscle tissue elements (typically at the myo-tendinous junction).
the damage to connective and muscle tissue elements is typically ultrastructural damage to the sarcomeres.
what does muscle injury result in?
deficit in tension generating capabilities of muscle, strength loss and other signs and symptoms of acute injury.
what are the three steps to muscle repair?
- degeneration
- regeneration
- fibrosis
what happens during degeneration?
a breakdown and removal of damaged cells and cellular debris
what is the inflammatory response during the degeneration phase and when does it begin?
a system of vascular and cellular events. begins immediately after injury
what happens during regeneration?
and activation of satellite cells, which signals myoblasts (muscle cell that wants to regenerate)
what happens during the fibrosis stage?
activation of fibroblasts (tissue that scars)
what tends to win in the competition between myoblasts and fibroblasts?
fibroblasts
what are the two problems with fibrosis?
- a lack of a signal to shut off or down-regulate fibrosis
- over expression of collagen
what propagates fibrosis?
TGF-beta1
what is tendon
tight, parallel bundles of collagen that are “virtually dead during life”
what do tendons do?
transmit forces of muscle to bone for joint movement and stability.
are tendons highly vascularized and innervated?
no
are tendons exposed to high mechanical load in tension?
yes
what are tendon injury responses characterized by?
Tissue degenerative process.
what is tendinopathy?
used to describe tendon-related symptoms that develop from overuse
what is tendinosis?
Used to describe intra-tendinous degeneration
Should you start with low load and high repetitions for tendons, or high load and low repetitions?
low load and high repetitions.
is tendon responsive to eccentric loading exercises?
yes
