Injury Response Process

Treating an injury with thermal, electrical, mechanical, or light energy, we...

Attempt to provide the optimal environment for healing to occur

Therapeutic Modality

a form of stress applied to the body for the purpose of eliciting an involuntary physiological response

Physical Stress Theory

describes how tissues react relative to the amount of stress they receive relative to normal

General Adaptation Syndrome (three stages of stress response)

alarm, resistance, exhaustion

Alarm Stage

Body's initial sudden reaction to a change in homeostasis

Resistance Stage

Body continues to adapt to the stressor by using homeostatic resources to maintain its integrity

- longest phase of the general adaptation syndrome, lasting many days, months, or years

Exhaustion Stage

Occurs when the body cannot withstand stresses

- stage may present as traumatic or overuse injuries (goal: stay out of this stage!)

Macrotrauma

acute injury (sprains, strains, fractures, etc)

Microtrauma

Repeated, relatively low-intensity forces can cause stress fractures, chronic inflammatory conditions, and muscle soreness

Wolff's law

bone adapts to the forces placed on it

Epithelial tissue (1st layer of skin)

- secretes and absorbs various substances and has the distinction of being devoid of blood vessels

- the skin's outer layer is formed by stratum corneum, a layer of flat, densely packed dead cells

Adipose Tissue

- consists of fat cells

- high water content

Muscle tissue

smooth, skeletal, cardiac

smooth muscle

Involuntary muscle found inside many internal organs of the body

cardiac muscle

Involuntary muscle tissue found only in the heart.

skeletal muscle

Voluntary muscle attached to bones. (type 1 & type 2)

Type 1 (Slow-twitch)

muscle fibers are slow to fatigue and are prevalent in postural muscles (posterior-chain, back muscles, etc.)

Type 2 (fast-twitch)

muscle fibers are capable of generating a high amount of force in a short amount of time

Nervous tissue

Nerves conduct afferent and efferent impulses via action potentials: dendrites (1), nerve body (2), axon (3)

- most therapeutic modalities have some affect on nerve function (NA-K pump) and slow rate of painful nerve transmission

Connective tissue

The most abundant type of tissue in the body that is produced by fibroblasts, formed by cell matrix and collagen(fascia, tendons, ligaments, etc.)

Primary injury

associated with the tissue destruction directly resulting from the traumatic force

Secondary injury

cell death caused by a blockage of oxygen supply to the injured area (ischemia) or caused by enzymatic damage and mitochondrial failure.

- Treatment efforts used after trauma attempt to limit the amount of secondary injury

Phases of the healing process

1. acute inflammatory response (0-3 days)

2. proliferation phase (1-10 days)

3. maturation phase (3-30 days)

Acute Inflammatory Response

Inflammation is a necessary part of the healing process (we just manage it)

- Migration of phagocytes and fibroblasts to the area and formation of granulation tissue isolate and localize the trauma

- Histamine released from the traumatized cells increases capillary permeability, resulting in swelling as the proteins follow water out into the tissues

Stages of inflammation after injury

acute (0-14 days)

subacute (14-31 days)

chronic (>31 days)

Proliferation Phase

The number and size of fibroblasts increases, causing ground substance and collagen to collect in the traumatized area in preparation to rebuild the damaged tissues

- revascularization

- wound contraction

- wound remodeling

Maturation phase

- number of fibroblasts, myofibroblasts, and macrophages is reduced to the preinjury level

- number of capillaries, the overall vascularity of the area, and water content are reduced

- proportion of type 1 collagen continues to increase, replacing the existing type 3 collagen and other parts of the collagen lattice

Cardinal signs of inflammation

redness, swelling, heat, pain, loss of function

Swelling

increase in the volume of a body part as the result of fluid build-up

Edema

build-up of excessive fluids and protein in the interstitial space resulting from the imbalance between pressures inside and outside the cell membrane of an obstruction of the lymphatic return and venous return mechanisms

- Ice application reduces edema formation

- removed by increasing venous and lymphatic return

Starling's Law

Describes the movement of fluids across the capillary membrane that results in the formation or removal of swelling

Muscle spasm

involuntary contraction of muscle fibers

- direct trauma, decreased O2, neurological dysfunction

Muscle atrophy and weakness

- Disuse atrophy and denervation

atrophy

- Edema and inflammation

stimulate Golgi tendon organs,

increasing the rate of atrophy