Injury Mechanisms and Classification Flashcards
Most common type of injuries?
- 90% musculoskeletal
3 ways injuries can occur?
- Mechanical (physical injury)
- Biological Agents
- Chemical Agents
What is trauma and how does it occur?
- Physical injury or wound produced by External or Internal force.
- Occurs when force is greater than the tissue can withstand.
What is Inflammation and the 5 signs?
Body’s response to injury.
1. Redness
2. Swelling
3. Heat
4. Pain
5. Loss of function
Acute vs Chronic injury
- Acute injuries only last for a short period of time. (sudden onset)
- Chronic injuries are long term injuries.
Load
- External Force acting on internal tissues
Stiffness
Ability of tissue to resist a particular load.
What is Hooke’s Law
- Strain is proportional to the stress producing it (as long as the strain is not too great - once that limit is exceeded, change occurs)
Stress
- Internal resistance to external load
Strain
- How much the shape of the tissue changes after loading.
Yield Point
Elastic limit of tissue
What is Plastic Change?
- Change in the tissue that lasts after load is removed.
- When this occurs over time, it is called creep.
What is mechanical failure?
Exceeding the ability to withstand stress and strain causing tissue to breakdown.
What are the 5 types of tissue loads?
- Compression
- Tension
- Shearing
- Bending
- Torsion
Compression
- External loads are applied toward on another on opposite sides of the structure.
- Shortens and widens the structure.
Tension
- Force that pulls or stretches tissue
Shearing
- Equal load is applied to apposing surfaces forcing those surfaces to move in parallel directions.
Bending
- External force is applied to a joint causing a bend.
Torsion
- Twisting in opposite directions from opposite ends of a structure cause a shear stress over the entire cross section of that structure.
Soft tissue vs. Hard tissue
- Hard tissue: Bone fracture
- Soft tissue:
a. Ligament
b. Muscle
c. Cartilage
d. Bursa
e. Nerve
What are the functions of Bones?
- Protects organs
- Stores minerals
- Helps as lever to provide movement to skeletal muscles.
What is cortical in the bone?
- Dense outer surface of skeletal bone.
- High resistance to bending and torsion.
What is trabecular in the bone?
- Internal tissue of bone (spongy)
- House bone marrow
What are the 6 fracture classifications?
- Greenstick: incomplete break, usually adolescents.
- Comminuted: 3 or more fragment sites
- Linear: Jumping from a height, line going straight down.
- Transverse: Direct blow
- Oblique: Torsion or twisting
- Spiral: Rotational/twisting force