MSS- Muscle injury

Question 1

what are the 4 main phases of muscle healing

Answer 1

bleeding (acute - hours)
inflammation (acute/ sub-acute- hours/days)
proliferation (acute / sub-acute / chronic- hours / days / weeks)
remodelling (end of subacute / chronic - weeks /months)

Question 2

what is the degeneration phase

Answer 2

bleeding and inflammation phase are sometimes referred to like this

Question 3

what is the regeneration phase

Answer 3

proliferation phase

Question 4

describe the bleeding phase

Answer 4

bleeding following an injury
starts immediately after injury and lasts 6-8 hours
dependent on tissue type
blood cells and plasma are released into the wound site along with other factors such as ATP
platelet activation promotes cascade of events which aide healing process
clotting cascade

Question 5

describe the inflammatory phase

Answer 5

stop bleeding via multiple vascular, cellular and chemical interactions and reactions occurring simultaneously
key features -
redness, swelling, heat, pain, loss of function

blood vessels dilate - increase blood flow to the area
capillaries become leaky - oedema
neutrophils/ monocytes and other WBC enter the area

Question 6

describe the proliferation phase

Answer 6

fibroplasia - formation of fibrous tissue via increase in extracellular collagen production - provide strength and integrity to the healing

myofibroblasts- cause wound contraction to minimise scar- fibroblasts turn into myofibroblasts- thick actin protrusions extend to wound edges - angiogenesis - formation of new blood cells

Question 7

describe the remodelling phase

Answer 7

orientation of collagen fibres - after injury collagen fibres are arranged randomly
pressure and strain of healing leads to reorientation of collagen fibres into a weak structure which resembles original collagen matrix
collagen deposition (type 1 replaces type 3 collagen)
capillaries diminish in number
tensile strength increases

Question 8

what is the difference between type 3 and type 1 collagen

Answer 8

type 3- original collagen which is more elastic - has role in differentiation of fibroblasts into myofibroblasts- scaffolding and wound edges brought together

type 1 - laid to give tensile strength to the wound

Question 9

what are risk factors for healthy healing of soft tissue

Answer 9

history of injury 
fatigue / overuse
weak muscles
decreased flexibility
failure to stretch  /warmup
disease
high risk activities
mechanical dysfunction
increasing age
medication use - NSAID / steroids

Question 10

what are methods of muscle injury invesitation

Answer 10

radiological assessment
patient subjective history
objective assessment