Chp 9: Mechanisms And Characteristics Of Musculoskeletal And Nerve Trauma Flashcards
What does the stress-strain curve represent?
The relationship between the stress placed on various tissues and the deformation that occurs
Load
An external force acting on tissues that causes internal reactions within the tissues
Stiffness
The relative ability of a tissue to resist a particular load (great stiffness means it can withstand a greater magnitude of load)
Stress
Internal resistance of the tissues to an external load
Strain
Extent of the deformation of tissue when its loaded
Deformation
The internal strain placed on the tissues from that stress results in deformation
Elasticity
A property that allows a tissue to return to normal following deformation
Yield point
Point where tissue is deformed to the extent where it no longer reacts elastically
Plastic changes
Beyond the yield point, deformation persists after the load is removed and results in permanent or plastic changes to the tissue
Creep
The deformation in the shape/properties of a tissue that occurs w/the application of a constant load over time
Mechanical failure
Ability of the tissue to withstand stress and strain is exceeded resulting ultimately in injury to the tissue
Difference between ductile and brittle tissues?
Ductile tissues can deform significantly before failing and consequently have a longer plastic area. Brittle tissues can deform very little before failure.
What are five types of tissue loading that can produce stress and strain?
Compression, tension, shearing, bending, and torsion
Compression produced by what forces?
Produced by external loads applied toward one another on opposite surfaces in opposite directions
What does compression do to a structure?
Shortens and widens a structure
What types of injuries are a result of compressive forces?
Arthritic changes in cartilage, fractures, and contusions
Tension forces
Forces that pull or stretch tissue apart. (Equal and opposite external loads that pull a structure apart)
Injuries that occur due to tension?
Muscle strains and ligament sprains
Shearing forces
Equal but not directly opposite loads are applied to opposing surfaces, forcing those surfaces to move in parallel directions relative to one another
Bending forces
Convex surface is elongated and subject to tension while the concave surface is shortened and subject to compression
Torsion forces
Caused by loads twisting in opposite directions from the opposite ends of a structure
Torsion forces usually result in what injury?
Spiral fractures at an oblique angle in long bones
Review Chart of Classification and Load Characteristics of In juries
Muscle strain
Muscle is overstretched by tension, or forced to contract against too much resistance a separation/tearing of the fibers occurs
Grade 1 muscle strain
Some muscle fibers stretched/torn. Some tenderness and pain on active motion. Movement is painful but full ROM possible
Grade 2 muscle strain
A number of muscle fibers have been torn, active contraction of the muscle is extremely painful. Depression/divet can be felt in the muscle belly at the place where muscle fibers have been torn. Bleeding causes ecchymosis and hematoma although not immediately. ROM decreased due to pain(Some swelling may occur bc of increased capillary permeability)
Grade 3 muscle strain
Complete rupture of a muscle occurred in the area of a muscle belly at the point at which the muscle becomes tendon or the tendinous attachment to the bone. Significant impairment/total loss of movement due to disruption of nerve fibers. Initially pains intense but then lessens due to unloading of the muscle
Healing timeframe for a hamstring strain is typically?
6-8 weeks
Muscle Cramps
Involuntary muscle contraction commonly occuring in calf, hamstrings, quads, etc.
Muscle guarding
After injury, the muscles that surround the injured area contract to, in effect, splint the area, thus minimizing pain by limiting movement.
Muscle spasm
Involuntary muscle contraction that results in increased tension and shortening of that muscle or a group of muscles which interferes w/voluntary movement.
Why do muscle spasms occur?
Consequence of neurological damage or disease
Why do muscle cramps occur?
Occur due to altered neuromuscular control bc of high demand activities that overload/fatigue muscles
Describe a clonic muscle spasm
Alternates quickly between involuntary muscle contraction and relaxation
Describe a tonic muscle spasm
Rigid muscle contraction that lasts a period of time
Define spasticity
Condition in which theres an abnormal increase in muscle tone and stiffness that results in an involuntary ability to control those muscles
Spasticity is caused by?
Lesions affecting the upper motor neurons (nerve pathways) from the central nervous system (brain and spinal cord) to the muscles.
Spasticity occurs in which conditions?
Cerebral palsy, multiple sclerosis, traumatic brain injury, stroke, and spinal cord injury
Muscle soreness
Overexertion in strenuous exercise that results in muscular pain
What are the two types of muscle soreness?
Acute-onset muscle soreness, and delayed-onset muscle soreness
Describe acute-onset muscle soreness
Lasts a short time and occurs during and immediately after exercise
Describe delayed-onset muscle soreness
-occurs 12 hours after injury
-becomes most intense after 24-48 hours and then gradually subsides
-muscle becomes symptom free after 3/4 days
-DOMS is described as a syndrome of delayed muscle pain leading to increased muscle tension, swelling, stiffness, and resistance to stretching.
Causes of DOMS
-May occur from small tears in the muscle tissue, which seem to be more likely w/eccentric or isometric contractions
-May occur bc of disruption of the connective tissue that holds muscle tendon fibers together
How to prevent and treat muscle soreness
-prevented by gradually progressing the intensity of exercise over time
-treatment-static stretching, pnf stretching
Tendinopathy
A term used when referring either to tendinitis or tendinosis
Tendinitis
Inflammation of the tendon
Tendinosis
Microtears and degeneration of a tendon
Whats the difference between tendinitis and tendinosis?
tendinosis is whens theres chronic degeneration w/out inflammation.
-tendon may be visibly swollen w/stiffness and restricted motion (tendinosis)
How to treat tendinosis
Engage in exercises to strengthen the tendon and consistently stretch the tendon
Tenosynovitis
Inflammation of the fluid-filled sheath surrounding a tendon
Difference between a trigger point and a tender point
-trigger point when palpated produces referred/radiating pain
-tender point when palpated only produces pain in that area
Myositis ossificans
-if a muscle is bruised repeatedly, then calcium deposits form in the injured area and begin to significantly impair movement
Treatment of myositis ossificans
Protect area w/padding and rest to allow calcium deposits to reabsorbed
Define atrophy, main causes
-atrophy is a loss of muscle mass
-causes: immobilization, inactivity, loss of nerve innervation
Define muscle contracture, list causes
-muscle contracture is an abnormal shortening of the muscle tissue in which theres a great deal of resistance to passive stretch
-contracture is associated w/a joint that bc of muscle injury, has developed unyielding and resisting scar tissue
Grade 1 ligament sprain
-some stretching and separation of fibers
-minimal instability of the joint
-mild to moderate pain, localized swelling, and joint stiffness
Grade 2 ligament sprain
-some tearing and separation of the ligament fibers
-moderate instability of the joint
-moderate to sever pain, swelling & joint stiffness
Grade 3 ligament sprain
-total tearing of the ligament
-instability of the joint (can result in subluxation)
-initially severe pain, can be followed by no pain as a result of total disruption of nerve fibers
-large amounts of swelling and stiffness
Diastis
Separation of 2 articulating bones
Dislocation
One bone in a joint is forced completely out of its normal/proper alignment and requires surgery to be put back into place
Subluxation
Similar to a dislocation except the bones comes partially out of its normal articulation and then goes back into place
Osteoarthritis
Degeneration of cartilage, remodeling of subchondral bone, and synovial inflammation
Osteoarthritis causes
Caused by direct blow/fall, pressure of carrying/lifting heavy loads, or by repeated trauma to the joint (running/cycling)
Osteoarthritis most commonly affects what joints?
Weight-bearing joints: knees, hips, lumbar spine. Can also occur in shoulders and cervical spine
Symptoms of osteoarthritis
-Most distinct symptom is pain, brought about by friction that occurs w/use and is relieved by rest
-Stiffness (usually in the morning) and loosened w/activity
-localized tenderness, creaking, grating that may be felt and heard
Chronic synovitis
-occurs w/repeated joint injury or joint injury that is improperly managed
-involves active joint congestion w/edema
-synovium of a joint can undergo degenerative tissue changes
-synovium can become thickened, exudation occurs, and a fibrous underlying tissue is present
-several movements may be restricted and there may be joint noises like grinding/creaking
Outside covering of the bone, and what it contains
Periosteum, contains the blood supply to the bone
Five basic functions of bones
- Body support
- Organ protection
- Movement (through joints & levers)
- Calcium storage
- Formation of blood cells (heamtopoiesis)
Examples of flat bones
Skull, ribs, scapulae
Examples of irregular bones
Vertebral column, bones in the skull
Examples of short bones
In the wrist and ankles: tarsals, carpals
Examples of long bones
Humerus, ulna, femur, tibia, fibula, and phalanges
Greenstick fractures usually occur in what kind of bones?
Bones that aren’t fully ossified
Comminuted fracture moi
Hard blow or fall in awkward position
Linear fracture moi
Jumping from a height and force is placed along the long axis
Transverse fracture moi
Direct outside blow, bending
Oblique fracture moi, forces involved
One end of the bone receives torsion/twisting while the other end is fixed, combination of axial compression, bending, and torsion
Spiral fracture moi
Foot is firmly planted when the body is suddenly rotated in opposing direction
Wolffs law states
If loading on a particular bone increases, the bone will remodel itself over time to become stronger to resist that sort of loading. (Textbook def: every change in form and function of a bone, or in its function alone, is followed by certain definite changes in its internal architecture).
Causes of stress fractures
-overtraining
-going back to competition too soon after injury/illness
-going from one event to other w/out proper training in the second event
-starting initial training too quickly
-changing habits/the environment (running surfaces, shoes)
What postural conditions increase susceptibility of stress fractures?
-flat feet
-short 1st metatarsal bone
-hypermobile metatarsal region
Most common sites for stress fractures
Tibia, fibula, metatarsal shaft, calcaneus, femur, pars interarticularis of lumbar vertebrae, ribs, and humerus
Type 1 salter harris
Complete separation of the physis in relation to the metaphysis w/out fracture to the bone
Type 2 salter harris
Separation of the growth plate and a small portion of the metaphysis
Type 3 salter harris
Fracture of the physis
Type 4 salter harris
Fracture of a portion of the physis and metaphysis
Type 5 salter harris
No displacement of the physis, but crushing force can cause growth deformity
Salter-harris injuries aka?
Epiphyseal growth plate injuries
