lecture 7

Question 1

what is muscle strain?

Answer 1

when tension exceeds the weakest structure element

Question 2

where would the muscle strain be located?

Answer 2

located near the muscle tendon junction 0.1 mm-3mm proximity

Question 3

what causes muscle strain?

Answer 3

sudden over stretch or contraction and limb deceleration

Question 4

what happens when you have a sudden over stretch or contraction, limb deceleration…MOI?

Answer 4

Failure of Golgi Tendon Organ may play a significant role in muscle strain

Insufficient warm-up may contribute to muscle strain
Contributory Causes: corticosteroid injections, previous injury, disease

Question 5

what contributes to a muscle strain?

Answer 5

corticosteroid injections, previous injury, disease

Question 6

how many degrees of muscle strain are there?

Answer 6

3

Question 7

what is the first degree (mild) of muscle strain?

Answer 7

also known as strained muscle where fibers have been stretched or torn and pain is felt with full ROM but full range still present

Question 8

what can we note about the structure with a first degree muscle strain?

Answer 8

minimal structural damage and minimal hemorrhage

Question 9

what is the second degree (moderate) of muscle strain?

Answer 9

also known as a pulled muscle where fibers have been torn and active contraction is painful, depression palpable, some swelling and discoloration result

Question 10

what can we note about the structure with a second degree muscle strain?

Answer 10

partial tissue tear, significant loss of function and hemorrhage

Question 11

what is the third degree (severe) of muscle strain?

Answer 11

also known as a torn muscle where there is complete rupture of muscle or musculotendinous junction, significant impairment, with initially a great deal of pain that diminishes due to nerve damage

Question 12

what can we note about the structure with a third degree muscle strain?

Answer 12

complete tear, total loss of function, extensive hemorrhage

Question 13

what can we note about the impairment of third degree muscle strain?

Answer 13

impairment starts off with a lot of pain but dulls down due to nerve damage

Question 14

what can be done about tendon ruptures?

Answer 14

large tendon will require surgery

Question 15

what are muscle cramps and spasms?

Answer 15

painful involuntary contraction

attributed to dehydration/electrolyte imbalance

may lead to muscle or tendon injury

Question 16

how does muscle guarding work?

Answer 16

Following injury, muscles within an effected area contract to splint the area in an effort to minimize pain through limitation of motion

Involuntary muscle contraction in response to pain following injury

Question 17

how does muscle soreness work?

Answer 17

overexertion in strenuous exercise resulting in muscular pain and generally occurs following participation in activity that individual is unaccustomed with

Question 18

what are the two types of soreness?

Answer 18

acute onset muscle soreness

delayed onset muscle soreness

Question 19

what is acute onset muscle soreness?

Answer 19

accompanies fatigue, and is transient muscle pain experienced immediately after exercise

Question 20

what is delayed onset muscle soreness?

Answer 20

pain that occurs 24-48 hours following activity that gradually subsides (pain free 2-3 days later)

Question 21

what can cause delayed onset muscle soreness?

Answer 21

Potentially caused by slight microtrauma to muscle or connective tissue structures

Question 22

what can cause a muscle contusion?

Answer 22

blow to muscle results in muscle tearing then to a hematoma with a severe contusion sometimes difficult to distinguish from a complete tear

Question 23

what are the types of muscle contusions?

Answer 23

intermuscular and intramuscular hematoma

Question 24

what is an intermuscular hematoma?

Answer 24

bleeding between muscle fascia

Question 25

how is the intermuscular hematoma characterized?

Answer 25

Early migration of ecchymosis (a discoloration of the skin resulting from bleeding underneath) to distal part of limb

Question 26

how do intermuscluar hematomas generally heal compared to intramuscular hematomas?

Answer 26

heal more quickly than intramuscular hematomas

Question 27

what is a intramuscular hematoma?

Answer 27

bleeding within a muscle bundle

Question 28

how do we characterize an intramuscular hematoma?

Answer 28

more confined and localized, inflammatory response is exaggerated and there is an increased risk of myositis ossificans, residual scarring and compartment syndrome

Question 29

what is a specialized kind of intramuscular hematoma discussed in class, often times very severe?

Answer 29

compartment syndrome

Question 30

how does compartment syndrome develop?

Answer 30

it begins with a hemorrhage then increased pressure in the muscle unit leading into decreased blood flow resulting in ischemia, necrosis and gangrene

Question 31

what can cause compartment syndrome?

Answer 31

excessive exercise induced muscle damage

Question 32

describe compartment syndrome pain?

Answer 32

palpable tightness, shiny skin appearance often needing of surgery within 12 hours of damage

Question 33

what are the general stages in the healing of muscle trauma?

Answer 33

Inflammatory (Days 0-2)

Fibroplastic Proliferation (Days 3-6)

Fibroplastic Proliferation (Days 7-14)

Remodeling Maturation (Days 15-60)

Question 34

describe the healing process for stage 1?

Answer 34

• Cell Disruption → hemorrhage & edema
• Myofibular retraction and nerve axon damage
• Mononuclear cell invasion → increased inflammation
• Phagocytosis

Question 35

describe the healing process for stage 2?

Answer 35

• Increased rate of collagen synthesis by fibroblasts
• Muscle regeneration from “Satellite” cells
• Pulsed ultrasound

Question 36

describe the healing process for stage 3?

Answer 36

• Muscle fibers bridging begins (increased danger of re-injury)
• Tensile strength approximately 50% of normal
• Contraction is still inhibited by edema and pain

Question 37

describe the healing process for stage 4?

Answer 37

• High maturation of collagen and increase in tensile strength
• Replacement of initial or inferior tissue
• Permanent loss of tissue tensile strength is 7%

Question 38

describe the treatment process for stage 1?

Answer 38

• RICE (Rest, Ice, Compress, Elevate)
• Immobilization and protection
• NSAID drugs

Question 39

describe the treatment process for stage 2?

Answer 39

• Partial ROM exercise

- Gentle resistance work

Question 40

describe the treatment process for stage 3?

Answer 40

• Increased resistance work
• Progress to full ROM exercise
• Ultrasound and heat modalities

Question 41

describe the treatment process for stage 4?

Answer 41

• Progression of activity (increased intensity and duration)

Question 42

what cells are activated in damaged muscle?

Answer 42

satellite cells are activated, they replicate, migrate on basement membranes and fuse to form new muscle fibers

Question 43

Muscles cells and invading inflammatory cells release…

Answer 43

Growth factors and cytokines

Question 44

these cells are also known as the fountain of youth?

Answer 44

satellite cells

Question 45

review slides on satellite cells for the healing of muscle injury

Answer 45

15-19