1. The Injury Process

2. The Physics of Sports Injury
The human body consists of many different types of tissue, each serving a specific purpose
Connective tissue
The most common type in the body
Ligaments, retinaculum, joint capsule, bone, cartilage, fascia, and tendon (Cailliet, 1977)
Epithelial
Protection, secretion, and absorption
Muscular
Contraction
Nervous
Touch and conductivity

3. Connective tissue is involved in both acute and chronic injuries
50% of all injuries in some sports are acute in nature and involve either muscle or tendon tissue

4. Occur during eccentric contractions
Muscles and fascia are injured when excessive tension is applied while contraction is occurring
Occur during eccentric contractions
The simultaneous processes of muscle contraction and stretch of the muscle-tendon unit by an extrensic force (Safran et al., 1989)
Damage to strains typically is found at the proximal musculotendinous junction (MTJ)

5. Mechanical Forces of Injury
Type of Tissue
Connective
(Tendons)
Bone Tissue
Ligament Tissue
Tensile Force
Resist
Less effective
Compressive
Force
Poorly Designed
Absorb
More vulnerable
Shear Force
Mechanical Forces of Injury
Three types of forces:
Tensile Force
Compressive Force
Shear Force

6. Axial loading = force along the long axis
Ex) when the body is upright in standing position, body wgt creates axial loads on the femur and tibia
Shear force ex) spondylolisthesis, involving anterior slippage of a vertebra with respect to the vertebra below it
Compressive force = axial loading that produces a squeezing or crushing effect
Tensile force = axial loading in the direction opposite that of compression
Shear force = acts parallel or tangent to a plane passing through the object

7. Mechanical Forces of Injury
Each tissue type has a limit to how much force it can withstand
The limit has been referred to critical force (Nigg & Bobbert, 1990)
Factors such as age, temperature, skeletal maturity, gender, and body weight can affect the mechanical properties of ligaments

8. Physiology of Sports Injury
Body’s initial response to trauma is inflammation
3 phase process
Inflammatory phase
Fibroblastic phase
Remodeling phase

9. Inflammatory Phase 0-6 Days
Vasoconstriction promotes increased blood viscosity (thickness), reducing blood loss through bleeding
The platelet reaction initiates clotting and releases growth factors that attract reparative cells to the site
The coagulation cascade affects clot formation
The complement and kinin cascades provoke vasodilatation and increase blood vessel wall permeability, facilitating the migration of neutrophils and macrophages in plasma exudates to cleanse the site through phagocytosis
Phagocytosis = cell eating

10. Proliferation Phase 3 – 21 days
Connective tissues heal themselves by forming scar tissue
Fibroblasts (immature, fiber producing cells located in connective tissue) produce a supportive network of Types I and III collagen
The platelet response and hypoxic wound environment stimulate angiogenesis (formation of capillaries, which interconnect, resulting in the formation of new vessels)
Epithelial cells migrate from the periphery toward the center of the wound to enact re- epithelialization

11. Maturation Phase Up to 1+ years
Fibroblast activity decreases and habitual loading produces increased organization of the extracellular matrix
A return to normal histochemical activity allows for reduced vascularity and water content
Types I and III collagen continue to proliferate, replacing immature collagen precursors and resulting in contracture of the wound
Scar tissue formation results in decreased size and flexibility of the involved tissues
Remodeling causes collagen fiber alignment along lines of habitual stress, with tensile strength increasing for up to 2 years post injury

12. How the injury process affects soft tissue and bone…
Bone injuries heal similarly to soft tissues; however, osteoclasts migrate to the region of injury and remove destroyed cells and debris
Fibroblasts (osteoblasts) migrate to the injured area
New osteoblasts are manufactured
Osteoblasts develop collagen and cartilage called a callus
Callus fills the space between the fractured bone ends and can be seen on an x-ray
Callus is not of sufficient strength to substitute for the original bone; however, through maturation it becomes fully functional bone
-some type of immobilization is required
-severely displaced fractures, surgical placement of appliances such as plates and screws may be necessary to stabilize the bony fragments

13. Pain and Acute Injury…
Although inflammation is the most visible aspect of an acute injury, the athlete will complain of pain as the largest problem
Pain is defined as, “the perception of an uncomfortable stimulus or the presentation or response to that stimulus by the individual,” (Thomas, 1997)
Two types of pain
Psychological (emotional)
Physiologic (tissue damage)
Result of sensory input received through the nervous system that indicates the location of damage
An athlete with high pain tolerance may underestimate the severity of the injury
An athlete with low pain tolerance may exaggerate the severity of the injury
In short, pain may not be a useful indicator of the severity of an injury
-everyone copes with pain differently
-err on the side of caution, consertivative side

14. Common Modalities used to treat pain
Ice
Heat
Electrical Stimulation (e-stim)
Massage
Prophylactic wrapping

15. Intervention Procedures…
Suggested treatments of inflammation include the application of cyrotherapy (therapeutic use of cold),
Crushed ice packs, ice cups applied via massage, ice-water baths, commercially available chemical cold packs, and aerosol coolants (ethyl chloride)
After the acute inflammatory phase has passed, usually 48 to 120 hours following thermotherapy (therapeutic use of heat) may be appropriate
Hydrocollator packs, warm and moist towels, and ultrasound diathermy
US should be done under the direct supervision of the BOC ATC, PT or physician

16. Cyrotherapy and Thermotherapy
During first few minutes of the inflammatory phase, direct application of cold may reduce vasodilation, there by reducing the swelling
RICES should then be applied which stand for
Rest
Ice
Compression
Elevation
Support
Standard first aid procedure for sprains, strains, dislocations, contusions and fractures
-most effective way of applying cold to the body is a plastic bag filled with crushed ice
-risk of frostbite during the application of a bag of crushed ice is minimal
Ice helps reduce recovery time
Tissue cooling reduces the metabolic activity of the cells with reduces need for O2

17. May be useful during the final phases of injury
Thermotherapeutic agents may also have a beneficial effect on soft tissue injury
Research is unanimous that such treatments should never be applied during the acute inflammatory phase
If we heat the tissue during the early phases of the injury, the metabolic activity of the inflammatory agents increases, resulting in an increase in inflammation (Wilkerson, 1985)
May be useful during the final phases of injury
Increasing available oxygen and stimulating vasodilation
Heat increases local metabolic activities

18. Majority prescribed by a medical doctor
In addition to cold and heat therapy, pharmacologic agents – drugs designed to prevent swelling (anti-inflammatories) or drugs designed to prevent pain (analgesics) are often used to treat inflammation
Majority prescribed by a medical doctor
Some are available over the counter OTC
Should consult with parents prior to recommending any sort of pharmacologic agent, including OTC medications
Anti-inflammatories = drugs designed to prevent swelling (steroidal and nonsteroidal)
Analgesics = agent that relieves pain without causing a complete loss of sensation

19. Pharmacologic Agents
Classified into two groups: steroidal and nonsteroidal anti-inflammatory drugs (NSAIDS)
Steroidal Anti-inflammatory Drugs
Best known is cortisone
Others commonly used include hydrocortisone, rednisone, prenisolone, trimcinolone, and dexamethasone
Even introduced through the skin via phonophoresis (using ultrasound energy) or iontophoresis (using electrical current)

20. Nonsteroidal Anti-Inflammatory Drugs
NSAID’s block specific reactions in the inflammatory process
Do not negatively affect collagen formation
Block the breakdown of arachindonic acid to prostaglandin, which in turn decreases the inflammatory response to injury
Done by decreasing the healing time or by increasing the strength of the new tissue
Commonly used NSAID on the treatment of acute ankle sprains

21. Best approach to treating the majority of soft-tissue injuries involves the application of RICES during the acute inflammatory phase
Followed by a combination of RICES, prescribed pharmacologic agent and prescribed and properly supervised rehabilitative exercises
The coach or other nonmedical personnel should provide only initial first aid to any soft-tissue injury then refer to appropriate medical authority

22. The Role of Exercise Rehabilitation
Most effective treatment for any sports injury, especially those involving soft tissue is physical activity
Need to have a properly constructed and supervised exercise regime
Research indicates that rehabilitative exercise can exert a variety of positive effects on collagen formation (AAOS, 1991)

23. According to knight (1995), exercise is essential during the healing process for two reasons
1. Exercise results in increased circulation with a concomitant increase in oxygen supply to the healing tissue
2. Exercise stresses the healing tissue and in essence “guides” the proper structuring of collagen
The process of collagen formation and tissue regeneration requires 2 to 3 weeks
Have the area properly protected with adhesive taping, wrapping, or bracing
Return to participation by a medical professional with experience in sports injury

24. An injury severe enough to warrant a medical diagnosis should be treated with a comprehensive program of exercise rehabilitation
Rehabilitative exercise, often called therapeutic exercise, is a four-phase process consisting of categories of exercise based on a continuum of severity and recovery

25. 4 Phase Process
First, if the athletes injury is severe, the initial exercise involves the therapist moving the injured extremity through a series of passive exercises
Reestablishment of a normal range of motion (ROM)
Reduction of swelling and muscle spasm
Second, as injury improves the next phase becomes active assisted
Athlete becomes a working partner in the exercise process, making a voluntary effort to move the injured joint while being assisted by a therapist
Improved ROM and increased muscle strength

26. 4 Phase Process Thirdly, rehabilitation process is active exercise
Athlete continues moving the joint through a full ROM, using gravity as resistance to stimulate development of muscle strength
PT supervises activity, no physical assistance
Fourth, the final phase is resistive
External resistance is applied to the joint movements
Manual resistance, resistive exercise machine, free weights
Primary objective is to improve the strength of the muscles surrounding the injured area to protect the injured area from future injury
Must incorporate functional activities
Functional activities ex) running and cutting drills for those athletes in sports such as basketball, football and soccer