1. Mechanisms of Sports Trauma & Tissue Response to Injury

2. Trauma is defined as physical injury or wound, produced by internal or external force
Mechanical injury results from force or mechanical energy that changes state of rest or uniform motion of matter
Mechanical Injury

3. Tissue Properties Load
An external force acting on the body causing internal reactions within the tissues
Stiffness
Ability of a tissue to resist a load
Greater stiffness = greater magnitude load can resist
Stress
Internal resistance to a load
Strain
Internal change in tissue (i.e. length) resulting in deformation
Yield point
Point at which elasticity is almost exceeded
If deformation persists, permanent or plastic changes result
When yield point is far exceeded mechanical failure occurs resulting in damage

4. Tissue Loading Tension Compression Shearing Bending Torsion
Force that pulls and stretches tissue apart
Compression
Force that results in tissue being crushed – two forces applied towards one another
Shearing
Force that moves across the parallel organization of tissue
Bending
Two force pairs act at opposite ends of a structure (4 points)
Three forces cause bending (3 points)
Already bowed structures encounter axial loading
Torsion
Loads caused by twisting in opposite directions from opposite ends
Shear stress encountered will be perpendicular and parallel to the loads
Tissue Loading

6. When injury is acute – something has initiated the injury process
Injury becomes chronic when it doesn’t properly heal
Could define relative to mechanism
Traumatic (i.e. a direct blow) vs. Overuse (i.e. repetitive dynamic use over time)
Traumatic v. Overuse

7. Musculotendinous Injuries
Muscle Strains: Stretch, tear or rip to muscle or adjacent tissue
May range from minute separation of connective tissue to complete tendinous avulsion or muscle rupture
Muscle Strain Grades
Grade I - some fibers have been stretched or actually torn resulting in tenderness and pain on active ROM, movement painful but full range present
Grade II - number of fibers have been torn and active contraction is painful, usually a depression or divot is palpable, some swelling and discoloration result
Grade III- Complete rupture of muscle or musculotendinous junction, significant impairment, with initially a great deal of pain that diminishes due to nerve damage
Time required for healing may be lengthy
Often involves large, force-producing muscles
Treatment and recovery may take 6-8 weeks depending on severity
Return to play too soon could result in re-injury
Musculotendinous Injuries

8. Musculotendinous Injuries
Muscle Cramps: Painful involuntary skeletal muscle contraction
Muscle Guarding: Involuntary muscle contraction in response to pain following injury
Following injury, muscles within an effected area contract to splint the area in an effort to minimize pain through limitation of motion
Muscle Spasm: A reflex reaction caused by trauma
Muscle Soreness: Overexertion in strenuous exercise resulting in muscular pain
Generally occurs following participation in activity that individual is unaccustomed
AOMS/DOMS
Tendon Injuries
Wavy parallel collagenous fibers organized in bundles
Tears generally occur in muscle and not tendon
Repetitive stress on tendon will result in microtrauma and elongation
Results in weakness
Musculotendinous Injuries

9. Musculotendinous Injuries
Tendinitis: Gradual onset, with diffuse tenderness due to repeated microtrauma and degenerative changes
Without proper healing condition may begin to degenerate and be referred to as tendinosis
Tenosynovitis: Inflammation of synovial sheath
Myofascial Trigger Points: Discrete, hypersensitive nodule within tight band of muscle or fascia
Classified as latent or active
Develop as the result of mechanical stress
Latent trigger point
Does not cause spontaneous pain
Active trigger point
Causes pain at rest
Tender to palpation with referred pain
Contusions: Result of sudden blow to body
Atrophy: wasting away of muscle due to immobilization, inactivity, or loss of nerve functioning
Musculotendinous Injuries

10. Synovial Joint Injuries
Ligament Sprains: Result of traumatic joint twist that causes stretching or tearing of connective tissue
Grade I - some pain, minimal loss of function, no abnormal motion, and mild point tenderness
Grade II - pain, moderate loss of function, swelling, and instability with tearing and separation of ligament fibers
Grade III - extremely painful, inevitable loss of function, severe instability and swelling, and may also represent subluxation
Subluxation: Partial dislocations causing incomplete separation of two bones
Dislocation: Occurs when at least one bone in a joint is forced out of alignment and must be manually or surgically reduced
Osteoarthritis: Wearing away of hyaline cartilage as a result of normal use
Bursitis
Bursa are fluid filled sacs that develop in areas of friction
Sudden irritation can cause acute bursitis, while overuse and constant external compression can cause chronic bursitis
Synovial Joint Injuries

11. Bone Injuries Fracture: break or crack in a bone Stress fractures:
Types of fractures
Greenstick
Comminuted
Linear
Transverse
Oblique
Spiral
Impacted
Stress fractures:
Overload due to muscle
contraction, altered stress
distribution due to muscle
fatigue, changes in surface,
rhythmic repetitive stress
vibrations
Bone Injuries

12. Bone Injuries Epiphyseal Conditions: Apophyseal Conditions:
Fracture in a growth plate
Apophyseal Conditions:
Apophysis is a protrusion from a bone
Traction injury
Osgood-Schlatter’s Disease, Saver's Disease
Bone Injuries

13. Nerve Injuries Compression and tension are primary mechanisms
Neuropraxia: Interruption in conduction through nerve fiber
Brought about via compression or blunt trauma
Impact motor more than sensory function
Temporary loss of function
Nerve Injuries

14. Tissue Response to Injury
Essential for athletic trainer to possess in depth knowledge of healing process
Understand phases
Time frames physiological changes associated with each phase
Healing is a continuum
Tissue Response to Injury

15. Signs of Inflammation Rubor Tumor Calor Dolor Loss of Function Redness
Swelling
Calor
Heat
Dolor
Pain
Loss of Function
Signs of Inflammation

16. Phases of Inflammatory Response
Phase I: Inflammatory Response Phase
Healing begins immediately
Injury results in altered metabolism and liberation of various materials
Initial reaction by leukocytes and phagocytic cells
Goal
Protect
Localize
Decrease injurious agents
Prepare for healing and repair
Phases of Inflammatory Response

17. Phase I: Inflammatory Response
Clot Formation
Platelets adhere to exposed collagen leading to formation of plug (clot)
Clots obstruct lymphatic fluid drainage and aid in localizing injury
Requires conversion of fibrinogen to fibrin
Initial stage: thromboplastin is formed
Second stage: Prothrombin is converted to thrombin due to interaction with thromboplastin
Third stage: thrombin changes from soluble fibrinogen to insoluble fibrin coagulating into a network localizing the injury
Chronic Inflammation
Occurs when acute inflammatory response does not eliminate injuring agent
Tissue not restored to normal physiologic state
Involves replacement of leukocytes with macrophages, lymphocytes and plasma cells
As inflammation persists necrosis and fibrosis prolong healing process
Phase I: Inflammatory Response

18. Phase II: Fibroblastic Repair
Scar formation through 3 phases
Resolution (little tissue damage and normal restoration)
Restoration (if resolution is delayed)
Regeneration (replacement of tissue by same tissue)
Fibroplasia: formation of a scar
Complaints of pain and tenderness gradually subside during this period
Scar Formation
Capillary buds form
Formation of delicate connective tissue (granulation tissue)
Consists of fibroblasts, extracellular matrix, develop collagen, elastin, ground substance
With proliferation of collagen scar tensile strength increases
# of fibroblasts gradually diminishes
Normal sequence = minimal scarring
Persistent inflammation = extended fibroplasia
Phase II: Fibroblastic Repair

19. Phase III: Maturation & Remodeling
Long-term process
Realignment of collagen relative to applied tensile forces
Continued breakdown and synthesis of collagen = increased strength
Tissue will gradually assume normal appearance
May require several years to complete
Phase III: Maturation & Remodeling

21. Factors That Impede Healing
Extent of injury
Corticosteroids
Edema
Keloids and Hypertrophic Scars
Hemorrhage
Infection
Poor Vascular Supply
Humidity, Climate, Oxygen Tension
Separation of Tissue
Health, Age, and Nutrition
Muscle Spasm
Atrophy
Factors That Impede Healing

22. Cartilage Healing Limited capacity to heal
Little or no direct blood supply
If area involves subchondral bone (enhanced blood supply) granulation tissue is present and healing proceeds normally
Cartilage Healing

23. Proper care will result in acute repair, and remodeling phases in same time required by other vascular tissues
Repair phase will involve random laying down of collagen which, as scar forms, will mature and realign in reaction to joint stresses and strain
Full healing may require 12 months
Surgically repaired ligaments tend to be stronger due to decreased scar formation
Exercised ligaments are stronger
Exercise vs. Immobilization
Muscles must be strengthened to reinforce the joint
Increased tension will increase joint stability
Ligament Healing

24. Skeletal Muscle Healing
Initial bleeding followed by proliferation of ground substance and fibroblast
Myoblastic cells form = regeneration of new myofibrils
Collagen will mature and orient along lines of tension
Healing could last 6-8 weeks depending on muscle injured
Skeletal Muscle Healing

25. Tendon Healing Requires dense fibrous union of separated ends
Abundance of collagen is required for good tensile strength
Too much = fibrosis – may interfere with gliding
Initially injured tendon will adhere to surrounding tissues (week 2)
Week 3 – tendon will gradually separate
Tissue not strong enough until weeks 4-5
Tendon Healing

26. Management of Injuries
Therapeutic Modalities
Heat: facilitates acute inflammation
Cold: slows inflammatory process
Ultrasound, electrical stimulation: treat inflammation
Therapeutic Exercise
Pain free movement, full strength, power, and tissue extensibility
Immobilization, while sometimes necessary, can have a negative effect on injury healing
Early mobilization may enhance healing
Management of Injuries

27. Bone Healing Acute fractures have 5 stages
Hematoma formation
Cellular proliferation
Callus formation
Ossification
Remodeling
Trauma to the periosteum and surrounding soft tissue occurs due to the initial bone trauma
Hematoma occurs during first 48 hours
Osteoblasts fill the internal and external calluses to immobilize the site
Hard callus becomes more well-formed as osteoblasts lay down cancellous bone, replacing cartilage
Ossification is complete when bone has been laid down and the excess callus has been resorbed by osteoclasts
Time required is dependent on various factors
Severity and site of fracture
Age and extent of trauma
Bone Healing

28. Problems with Bone Healing
Poor Blood Supply
Bone may die and union/healing will not occur (avascular necrosis)
Head of femur, scaphoid, talus, base of 5th metatarsal
Poor Immobilization
Poor casting allowing for motion between bone parts
Patient not following immobilization recommendations
May prevent proper union or result in bony deformity
Infection
Interferes with healing
More common with compound fractures
Soft tissue alterations could cause non-union
Problems with Bone Healing

29. Types of Pain Cutaneous: sharp, bright, burning, fast and slow onset
Deep Somatic: originates in tendons, muscles, joints, periosteum and blood vessels
Visceral: begins in organs and is diffuse at first and may become localized
Psychogenic: felt by individual, but is emotional rather than physical
Fast vs Slow:
Fast: localized and carried through A-delta fibers
Slow: perceived as aching, throbbing or burning; through c-fibers
Acute vs Chronic:
Acute: less than 6 months duration
Chronic: longer than 6 months duration
Referred Pain: occurs away from actual site of injury/irritation
A-alpha fibers are sensitive to pressure and can produce paresthesia
Myofacial, scleromatic, and dermatomatic
Types of Pain

30. Myofascial Pain: trigger points, acute or chronic Scleromatic: travels on C fibers; deep, aching, poorly localized pain; can cause depression, anxiety, fear, anger; autonomic changes (Bp, sweating) Dermotomic: irritation of A-delta fibers; sharp, localized
Referred Pain

31. Pain Control Gate Control Theory: at spinal cord level
Sensory information from receptors on cutaneous tissue enter A-beta fibers
Pain simultaneously travels along A-delta and C- fibers
Sensory information overrides the pain information, “closing the gate”
Pain message isn’t received
Pain Control

32. Self report is the best reflection of pain and discomfort
Techniques
Visual analog scales (0-10)
Pain Charts
McGill pain questionnaire
Numeric rating scale
Pain Assessment

33. Pain Assessment

34. Treating Pain Modalities
Used to relieve pain and control other s & sx of injury/surgery
Use in conjunction with exercise
Induced analgesia (pain reduction/removal)
Thermal agents for pain control
Electrical modalities to reduce pain control
TENS, superficial heat/cold, massage used to target gate control theory
Electrical stimulation, deep massage
Pharmacological Agents
Oral, injectable medications
Analgesics and anti-inflammatories
Referring physicians or pharmacists
ATs are not allowed to dispense medications to minors
Treating Pain