Chapter 9: Exam 1 Flashcards
Trauma
A physical injury or wound produced by internal or external force
Why must an ATC know about the mechanics of an injury?
Knowing how the injury occurred helps narrow down what the injury might be
What causes mechanical injuries?
Result from force or mechanical energy that changes state of rest or uniform motion of matter
Load
An external force acting on the body causing internal reactions within the tissue
Stiffness
Ability of a tissue to resist a load (greater stiffness=greater magnitude a load can resist)
Stress
Internal resistance to a load
Strain
Change in shape tissue (ex. Length)
Elastic deformation
Occurs until the yield point and plastic deformation occurs until failure point (can bend/stretch without injury)
Yield point
Point where elastic deformation turns to plastic deformation
How does tissue failure occur?
Results from forces that exceed the structural capacity of a tissue
Why does each tissue have a different failure point?
Different tissues have different structural properties and can withstand different amounts of force before tissue failure and injury occur
Compression
Force that results in tissue crush-2 forces applied towards one another
Tension
Force that pulls and stretches tissue
Shearing
Force that moves across the parallel organization of tissue
Bending
Two force pairs act at opposite ends of a structure (axial loading)
Torsion
Twisting in opposite directions from opposite ends (ex. High ankle sprain)
Types of Tissue Loading (5)
- compression
- tension
- shearing
- bending
- torsion
Primary injury
Direct immediate consequence of excessive force
Secondary injury
Delayed sometime after the initial trauma or an accommodation to the primary injury
Acute injury (trauma)
Mechanical failure of tissue due to excessive force occurring in a single bout (ex. Muscle strain, ligament sprain)
Chronic injury (overuse)
Mechanical failure of soft tissue due to repeated micro trauma occurring over an extended period of time. Gradual onset and prolonged duration (ex. Cramps, tendinitis, stress fracture)
Muscle strain
Stretch, tear, or rip to the muscle or adjacent tissue
Muscle strain causes (3)
Often unclear…
Abnormal muscle contraction due to..
-failure in reciprocal coordination of agonist and antagonist
-electrolyte imbalance due to profuse sweating
-strength imbalance
Ranges of muscle strains
Mild separation of connective tissue to complete tendinous avulsion or muscle rupture
Muscle cramps
Involuntary muscle contractions due to electrolyte imbalance
Muscle guarding
Muscle contraction in response to pain **natural splinting
Clonic muscle spams
Involuntary, alternate between contraction and relaxation rapidly
Tonic muscle spasms
Constant contraction for long period of time
Tendon
Attaches muscle to bone and double the strength of the muscle it serves
Tendon injuries
- tendinitis
- tenosynovitis
- strain/ rupture
Mechanism of tendon strain/ rupture
High magnitude, single load, tensile forces
Mechanism of tendinitis/ tenosynovitis
Low magnitude, repetitive load, tensile forces
Mechanisms of compressive forces
Bony structures and external compression
Tendinitis
Gradual onset and diffuse tenderness, swelling and pain, without proper healing it can worsen and become tendinosis or tensynovitis
***rest
Contusions
Results from a sudden blow to the body
Results of contusions
Hematoma results from blood flow and lymph flow into surrounding tissue.
Prevention of contusions
Padding
Myositis ossificans
Chronically inflamed and contused tissues may result in generation of calcium deposits
Prevention of tendon injuries
Gradual loading
Ligaments
Attach bone to bone and are strongest in the middle and weakest in the ends
Ligament injuries (ACL)
-High magnitude, single load, tensile force
Ligament injuries (shoulder instability)
Low magnitude, repetitive load, tensile forces (constant tensile forces lead to ligamentous deterioration)
Dislocations and subluxations
Caused by bony surfaces not articulating correctly and results in separation of bony articulating surfaces
Subluxation
Partial dislocation causing incomplete separation of two bones. Bones spontaneously come back together
Dislocation
Total disunion of bony alignment which must be manually or surgically reduces (gross deformity)
Bone anatomical characteristics
- dense connective tissue matrix
- outer compact tissue
- inner porous cancellous bone
Epiphysis
End of the bone—> spongy bone surrounded by compact bone
Diaphysis
Center of the bone—>dense
Bone fractures classification
- open
- closed
Closed fracture
Little movement or displacement
Open fracture
Displacement of the fractured ends and breaking through the surrounding tissue
Signs and symptoms of bone fractures
- deformity
- pain
- point tenderness
- swelling
- pain on active and passive movements
- false joint
- possible crepitus
How to get a definite diagnosis for fracture
X-Ray
Seriousness of fracture
Serious if not managed properly
Greenstick fracture
Splinters
Comminuted
Compressive, crushed
Linear
Parallel
Transverse
Horizontal
Oblique
Diagonal
Spiral
Twisting; looks diagonal
Depressed fracture
Depressed below the normal surface (skull)
Epiphyseal conditions (3)
- injury to growth plate
- articular epiphysis
- apophyseal injuries
Epiphyseal injury ages
10-16 years old b/c bone is not fully developed and still growing
Classification of Epiphyseal conditions
Salter-Harris (5 types)
Stress Fracture other names
“March” “fatigue”
Cause of stress fracture (7)
Exact cause unknown:
- overtraining
- amenorrhea/ hormonal imbalance
- inadequate nutrition
- returning to competition too soon
- “too much too fast”
- footwear or foot biomechanics
Stress fracture symptoms
- swelling
- point tenderness
- vibration percussion will cause pain at site
Stress fracture treatment
- treated early-bony changes might not show up for several weeks
- rest
- immobilization
Most common nerve injury
Neuropraxia; produced by direct trauma
Common ways nerves get lacerated and compressed
Fractures and dislocations
What can abnormal nerve responses be attributed to?
Injury or athletic participation
Nerve responses to stress
- anesthesia
- paresthesia
- hyperesthesia
Anesthesia
Loss of sensation
Paresthesia
Altered sensation
Hyperesthesia
Increase sensitivity
Primary mechanisms of nerve injuries
Compression and tension
Nerve injuries:acute or chronic
Either
Neuropraxia
Interruption in conduction through nerve fiber
Neuropraxia cause
Compression or blunt trauma
Neuropraxia symptoms
- impact motor more than sensory
- temporary loss of function (hours to months)
Are nerve injuries painful?
Sometimes
Burner/stingers
- Caused by traction (most common) or compression
- nerves are stretched
- if repeated, it can cause long term injury
