The Injury Process

The Physics of Sports Injury

Connective Tissue

• Connective tissues are the most common type of tissue in the body.

• Connective tissues include *, retinaculum, joint capsules, *, cartilage, *, and tendons.

• In some sports, nearly * of acute injuries involve either tendon or muscle.

The Physics of Sports Injury (cont.)

• Muscle/fascia are thought to be injured when excess tension is applied while contraction is occuring.

• More injuries to the muscles and fascia occur during eccentric contractions

• Tendons are extremely strong structures; strains occur most often at the distal musculotendinous junction (MTJ).

• These strains are the most common soft tissue injuries related to sports.

Mechanical Forces of Injury

Types of Force• Compressive-

• *are poorly designed to deal with these forces• * is designed to absorb these forces• * are more vulnerable to compressive forces

• Tensile-• Tendons are designed to *tensile forces• Bone tissue is less effective against tensile forces• Ligaments are designed to resist tensile forces

• Shear-• Tendons are less effective when dealing with

shear forces• Bone tissue is less effective against shear forces• Ligaments are more * to shear forces

* Each type of tissue has a limit for how much force it can withstand (critical force)

The Physiology of Sports Injury

The inflammatory process:• Is a predictable sequence of physiologic actions

that occur when the body reacts in a manner to repair damaged tissues.

• Begins *

Regardless of what tissue has been injured, the body’s initial response to trauma is *

The Inflammatory Process (cont.)

Normal signs and symptoms of inflammation include:

• Swelling.

• *

• Reddening of skin (erythema).

• *

The Inflammatory Process

Consists of several specific phases:•Acute Phase•*•Regeneration and Repair Phase

Acute Inflammatory Phase

• When tissues are damaged, millions of cells are *.• Initially blood flow to the area is reduced

(vasoconstriction)• Only a few minutes later, it is followed by an increase

is blood flow (vasodilation)• The sudden increase in blood flow into the interstitial

spaces (between the cells) results in the formation of a *

• Blood flow during the acute inflammatory phase may increase * over normal

Acute Inflammatory Phase (cont.)

Three specific groups of chemicals have been identified as being active during the acute phase.

1. Degenerative enzymes (*)

2. Vasoactive substances (*)

3. Chemotactic factors (*)

Leukocytes are white blood cells

Acute Inflammatory Phase (cont.)

1. An enzyme known as * is always carried in the blood, and under the conditions of tissue damage it becomes active.

2. This then activates compliment systems that play major roles in the inflammatory reaction.

3. The process of attracting cells is known as * and is essential to the process of inflammation

4. The Hageman factor is also responsible for the manufacturing of * (chemical that increases vascular permeability)

5. Bradykinin then triggers the release of * (the most powerful chemicals produced in the body) which causes vasodilation, increased vascular permeability, * , fever, and * .

Acute Inflammatory Phase (cont.)

6. Vascular permeability is important because it allows large structures (plasma proteins, platelets, and leukocytes-mainly neutrophils) to pass out of capillaries and into the damaged tissue

7. Leukocytes use * (cell eating) to dispose of damaged cells and debris

8. Neutrophils arrive quickly to the site of injury, however they only live for about * and have no means of reproduction

9. When the * expires, they release a chemical that attracts a leukocyte known as a *

10.Macrophages consume cellular debris by way of phagocytosis, but unlike neutrophils, they can survive for months and have the ability to reproduce

Acute Inflammatory Phase (cont.)

• Another important chemical mediator is arachidonic acid

• Arachidonic acid serves as a precursor to the formation of other inflammatory chemicals including * and *

Acute Inflammatory Phase (cont.)

The acute inflammatory process results in a * of the damaged area from the rest of the body.

The process acts to clean up the debris and provide components for healing.

The acute phase lasts up to *, unless aggravated by additional trauma.

Resolution (Healing) Phase (2nd Phase)

During this phase, special leukocytes (polymorphs and monocytes) and a type of macrophage (histocytes) migrate into the area of injury.

• These cells break down cellular debris and set the stage for *.

Regeneration and Repair (3rd Phase)

Except for bone, connective tissues heal by forming * that begins to develop 3–4 days after the injury.• The regeneration process starts with the migration

of *• Fibroblasts (proteoglycan- and collagen-producing

cells) migrate into the damaged area and also help to *.

• Fibroblasts are immature connective tissue fibers that can mature into several different types of cells.

Regeneration and Repair (3rd Phase)

• The circulatory system begins to repair itself, specifically capillaries, thru a process called * within just a few days post injury.

• * may take up to four months.• Scar tissue can be * as strong as the original tissue. • Stress on the tissue is helpful for rehabilitation

because it encourages the new collagen fibers to form parallel lines (a stronger configuration)

• * are critical to this process.

Regeneration and Repair (3rd Phase)Bone

• Bone injuries heal in similar fashion to soft tissues• Specialized cells called * migrate to the injured site

and remove damaged cells and other debris• Specialized fibroblasts called * begin rebuilding by

forming a callus

Pain and Acute Injury

• Everyone copes with pain *.• Pain is as much psychological (*) as physiological

(tissue damage).• Pain results from sensory input received through the

nervous system and indicates location of tissue damage.

• Damaged tissues result in the alteration of * of the structures involved.

• The state of altered homeostasis triggers the pain response, and that causes the sensory nerve receptors to transmit impulses to the *.

Pain and Acute Injury

• *(nociceptive C fibers) send impulses when the pain is a result of external forces

• *send impulses for touch and temperature• Nociceptive fibers are slower for 2 reasons:

1. Their diameter is smaller

2. *

Pain and Acute Injury

• Afferent nerve messages sent to the CNS are ranked based on the number of impulses it sends. Higher number of impulses are given *.

• An example is when you hit your head on something – the first reaction is to rub the area

• Rubbing the injured area (touch) blocks the pain signals

• Since each person responds to pain differently, pain is not a useful *of the severity of injury.

Intervention Procedures

• Sports medicine community has no clear set of criteria for first aid treatment of acute soft- tissue injury.

*includes bags of crushed ice, aerosol coolants, ice cups, ice water immersion, and commercial cold packs.

After the acute phase, * is appropriate (i.e., hydrocollator packs, moist warm towels, and ultrasound diathermy).

Intervention Procedures (cont.)

• Modalities such as * should ONLY be used under the supervision of trained allied health personnel.

• Pharmacologic agents can be used, such as * and *.• If they must be prescribed by a physician, these

agents represent treatments that are beyond the scope of the coach.

• OTC drugs should also be used with caution. (Consult parents when athlete is under 18 years of age.)

• Application of the * method is universally accepted

Cryotherapy

• Direct application of cold may reduce vasodilation in the first few minutes after injury.

• Application of cold can * by reducing secondary hypoxic injury.

Cryotherapy (cont.)

• In extremities, elevation and compression are also helpful in treatment.

• * in a plastic bag is an inexpensive modality.• Elastic wrap secures the ice bag to the body.• Cold application has an analgesic effect and

reduces *.• Recommended protocol: Apply for 30 minutes,

remove for 2 hours, and reapply for another 30 minutes, if needed.

• Risk of frostbite is * with crushed ice.

Cryotherapy (cont.)

• The application of ice during the acute inflammatory phase helps to * the recovery time

• Tissue cooling reduces the * in the injured area, thereby reducing the cellular need for oxygen.

• Cells are better able to survive the initial period of inflammation when * is in short supply

• This means there is less cellular debris to be collected – the repair phase can begin sooner

Thermotherapy

Thermotherapeutic agents:

• Should * be applied to an acute injury.

• Increase * which increases inflammation.

• Are useful in the final phases of injury repair by increasing available oxygen in the region of the injured tissues

• Heat also * local metabolic activities, including those resulting in regeneration of tissues.

Pharmacologic Agents

Steroidal and NSAIDs• Both affect aspects of the inflammatory process.• Steroidal drugs resemble gluococorticoids (naturally

occurs in the body), but the exact mechanism of their action is unknown.

Steroids may:• Decrease amount of chemicals released by * .• Decrease permeability of * .• Reduce WBC phagocytosis.• *.

Pharmacologic Agents (cont.)

Steroids must be used with care.• They can interfere with *,

decreasing connective tissue strength in injured area.

Steroids may be * or taken orally and include drugs such as:• Cortisone, hydrocortisone,

prednisone, and dexamethasone.

Pharmacologic Agents (cont.)

• *– using ultrasound to introduce salt ions into the body

• *– using electrical current to introduce the steroids into the body

NSAIDs

NSAIDs do not have the negative effects of steroids.• Do not negatively affect the *

• NSAIDs are very popular drugs.

• Common NSAIDs include *, ibuprofen, naproxen, indomethacin, and *.

NSAIDs (cont.)

• NSAIDs block the conversion of arachidonic acid to prostaglandin – this causes a * in the inflammatory response to the injury.

• Aspirin has anti-inflammatory, analgesic, and antipyretic effects.

• Research is * regarding NSAIDs’ effect on tissue healing and strength.

RICE

Best approach to the care of soft tissue injury is RICE along with prescribed pharmacologic agents and supervised rehabilitative exercise.

R = *

I = *

C = *

E = *

The Role of Exercise Rehabilitation

• Exercise is essential during the healing process for 2 reasons:

1. Exercise results in increase circulation which * to the healing tissue

2. Exercise stresses the healing tissue which causes the proper structuring of * (parallel formation)

Exercise Rehabilitation

• Collagen formation and tissue regeneration requires *.

• Care must be taken to not do too much too soon!

• Rehabilitation must be supervised by professionals with appropriate training, such as a BOC-certified Athletic Trainer or a Physical Therapist with sports medicine training.

Exercise Rehabilitation (cont.)

Rehabilitative exercise is a four-phase process.

1. *– therapist actually moves the injured area thru a series of exercises

2. *– athlete tries to perform the exercises while the therapist assists

3. *– the athlete performs all exercise with the resistance of gravity

4. * – external resistance is applied during the exercises

Injury Rehabilitation

• All rehab programs should focus on reestablishment of complete ROM (range of motion) as well as a decrease of * and *.

• Injury rehab should be considered an ongoing process.

• Injury-specific exercise should be a permanent component in training and conditioning.

• Without this approach, the likelihood of re-injury is *.