Transcript Injury Mechanisms and Classifications

Injury Mechanisms and
Classifications
Core Concepts in Athletic Training and Therapy
Susan Kay Hillman
Objectives

Describe the anatomical reference position.

Use appropriate anatomical terminology to describe the location and position of a structure relative to
the rest of the body.

Identify characteristics relating to the various stages of physical maturity.

Explain distinctiveness of the various types of musculoskeletal tissue.

Differentiate between elastic and plastic tissue properties.

Classify injuries as either acute or chronic based on the onset and duration of symptoms.

Define the common chronic inflammatory conditions, including signs and symptoms.

Define the various classifications of closed soft tissue wounds, including degrees of severity.

Define and classify closed and open wounds of the bone and joint articulations.

Classify nerve injuries according to mechanism, severity, and signs and symptoms.

Identify the classifications of open (exposed) wounds.
Introduction

Proper reference to anatomical positions, knowledge of
injury terminology, and mechanisms essential for
communicating effectively with other health care
professionals

Assist you in documenting findings, convey history
information during medical referrals, and collaborate
with other healthcare professionals regarding care of
your athlete
Anatomical Reference
Terminology

All anatomical descriptions and references are based on
standardized position of the body
 Anatomical Position
 Allows us to reference specific body regions in relation
to the body as a whole and one anatomical landmark to
another
 Avoid confusion and misinterpretation of your
findings
 Can be standing or supine (on the spine)
 Standing most common and easiest to visualize
Anatomical Reference
Terminology

Anatomical position

Feet together, flat on the ground, toes facing forward

Legs and knees straight and in line with hip, torso and
head, which are also straight and facing forward

Upper limbs positioned at persons side, with elbows
straight

Shoulders rotated so palms are facing forward
Anatomical Reference
Terminology

Once in anatomical position one can begin to refer to specific
structure using various anatomical terms

Describe position of body parts with reference to other
body parts or the body as a whole

Also synonyms reserved for particular body regions
 For example anterior=structure near front of body,
and anterior surface of hands is referred to as palmar
or ventral
Anatomical Reference
Terminology

From anatomical position can also define three anatomical planes of
movement useful in describing postural positions, motions, and
function of various muscles and joints
 Imaginary planes that separate the body into left and right
(sagittal or median), top and bottom (Transverse), and front and
back (frontal or coronal)
 For example when nodding your head or flexing your elbow
this occurs in the sagittal plane
 Shaking your head no or rotating your palms so it is facing
backwards takes plane in the transverse
 Lifting arms out to the side occurs in the frontal plane
Anatomical Reference
Terminology

Patient positioning terminology important and helpful
for understanding starting positions for various medical
testing
 Supine (face up) and prone (face down) refers to
patient laying down
 Short sitting-patient sitting on edge of table with legs
hanging off the edge
 Long sitting patient sitting with legs out in front of
them with legs on the table or floor
Physical Maturity
Classifications

Allows us to define stages of physical growth
 Normal anatomic and physiologic development from infancy to older
adulthood
 Infancy: (0-12 months) physical changes occur most rapidly.
 Dependent neonate to a child learning motor skills such as
turning, sitting, crawling and walking
 Gain 3 x birth weight in this time
 Childhood: (1-11 years) infancy to onset of puberty
 Steady growth and development
 Skeleton is immature with epiphyseal plates open to allow bones
to elongate
 1-5 early childhood, 6-11 middle childhood
Physical Maturity
Classifications

Adolescence: ( 11-13 through 18-20)
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Onset of puberty through full skeletal maturity
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Onset of Puberty marked by development of secondary sexual
characteristics


Females: menarche, pubic hair, development of breast

Males: Deepening of voice, pubic hair, and facial hair
Skeletal maturity marked by full closure (ossification) of epiphyseal plates
and cessation of further growth in height


Age at which bones complete ossification varies widely from early teens
to early 20’s
Adulthood (18-40 years)

Indicate full skeletal maturity and development

Bone and muscle mass increase through 25 to 30 years of age after which
mass levels off and then slowly declines

Middle adulthood (40-60 years)
 Gradual decline in strength coordination and
balance

Older adulthood (> 60 years)
 Spans rest of human beings life
 Accelerating decline in strength, coordination and
balance
 Highly individual depending on lifestyle, activity,
nutrition and disease
Injury Mechanisms

Foundation of body movements made up of several simple
machines
 Levers, pulleys, and wedges among other more complex
systems
 Bodies capable of performing very intricate and detailed
work along with incredible feats of strength, power and
endurance
 However, body influenced by internal and external
mechanical forces that can negatively affect performance
 Important to understand musculoskeletal system, physical
properties of the musculoskeletal tissue, internal and
external mechanical forces that can cause injury
Injury Mechanisms

Musculoskeletal Tissue

Five tissue types Categorized by Soft and Skeletal
Tissue

Soft tissue
 Muscles, tendons, ligaments, and cartilage

Skeletal Tissue
 Bone
Injury Mechanisms

Musculoskeletal Tissue Properties
 Degree and location of injury often determined by
tissue strength
 Musculoskeletal tissue has elastic and plastic
(inelastic) properties.
 Elastic properties manifested as response to
loading, stress or mechanical forces that cause
stretching or deformation of tissue
 After stress is removed tissue returns to
relatively normal state
Injury Mechanisms

Plastic Properties manifested at end range of elastic properties
rendering tissue unable to return to normal state

Tissue retains some amount of deformation due to structural
injury
• Yield point: determined by specific amount or level
of stress
• Example: stretching a rubber band. Point at which
it breaks is considered yield point
• Enough force to eliminate elastic property
recovery and cause rubber band to undergo
plastic deformation
Injury Mechanisms

Athletic injuries occur much the same way
 Tissue stress determined by amount of mechanical
force divided by total area affected
 If tissue stress, is low enough that tissue remains in
elastic property zone patient may only occur minor
injury or none at all
 If stress in high enough to force tissue to plastic
property zone injury severity and tissue damage
more significant
Injury Mechanisms

Individuals and individual tissue have an ability to
respond to and resist a certain amount of load or stress
before deformation
 As load or stress increases the potential for tissue
deformation also increases
 Type of force applied, along with the surface area
acted upon by the force , also affects the injury
 Given same velocity localized force can result in
substantially greater tissue damage than the dame
force applied over a broader surface area
Injury Mechanisms

Tissue damage may be the result:

unpredictable accident or injury

Overuse

Overload
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Poor posture
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Skeletal immaturity

Lack of conditioning

Improper mechanics

Fatigue

Inflexibility

Muscle imbalance

Genetics
Mechanical Forces

Stress or load applied to the body to cause injury or
tissue deformation is a result of 1 of 5 types of
mechanical force
 Excessive compression
 Squeezing or condensing of tissue due to external
forces applied directly opposite of each other
 Bruises (contusions)
 Crushing injuries (compression fractures)
 Pinching
 Injuries due to direct impact
Mechanical Forces

Shear
 Forces that cause tissue to “slide” over adjoining
surfaces or structures in a parallel fashion
 Brain injuries
 Tibiofemoral translation injuries such as ACL and
PCL injuries
 Blisters
 Lumbar spine injuries
Mechanical Forces

Torsion
 Twisting mechanism that causes rotation along long
axis or fixed point
 Opposite ends of tissue are rotated in opposite
directions
 Example: Body rotating over Foot fixed or lower
leg
 Occurs to bones and ligaments

Tension
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Stretching or lengthening of musculoskeletal tissue due
to stress or strain

Caused by pulling or drawing apart
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Pull of tissue in opposite direction causes tissue in
between to stretch

Muscle strains or ruptures commonly caused by
tension within the musculotendinous unit

Where muscle makes transition into tendon
• Weak part of muscle
Mechanical Forces

Bending
 Deformation of tissue into convex or concave shapes
due to axial loading
 Forces acting in opposite directions at different ends
of tissue
 Or significant impact to middle of tissue while the
ends are stable
 Convex surface undergoes tensile forces while
concave surface undergoes compression forces
 Example: Fibula fracture with direct blow
Mechanical Forces

Mechanical forces are not isolated
 Usually 2 or more mechanical forces acting on tissue
at one time
 Complex mechanisms and forces that come together
to cause injury
 Example: Lateral blow to knee with foot planted
 Compressive forces to lateral knee, bending force
to medial knee, shear and tension forces to middle
of knee
 Valgus force: toward midline
 Varrus Force: Away from midline
Time Classification Relating to
Mechanism of Injury

Acute Injuries
 Conditions that have sudden onset, short
duration, and occur via mechanical forces
that exceed elastic properties causing tissue
deformation

Single traumatic event: blunt force trauma,
dynamic overload of muscle, tendon, joint
capsule or ligamentous tissue
Time Classification Relating
to Mechanism of Injury

Chronic Injuries
 Gradual onset, prolonged duration, and occur as a result of
accumulation of minor insults or repetitive stresses
 Exact mechanism not often known
 Overuse, accumulative microtrauma, repetitive overloading,
abnormal friction that is greater than body's ability to heal
and recover before additional stress is added
 “too much, too soon, too often”
 Often more difficult to treat overuse (chronic) injuries than
acute injuries
Injury Classifications

Sign: finding that is observable or that can be
objectively measured
 Swelling, discoloration, deformity
 Crepitus: crackling, grating, or grinding sensation

Symptom: subjective complaint or an abnormal
sensation the patient describes but cannot be directly
observed
 Pain, nausea, altered sensation, fatigue
Injury Classifications

Closed (Unexposed) Wounds: Injury that does not
disrupt surface of skin
 Contusion or bruise
 Signs: swelling discoloration and deformity
 Compression of soft tissue due to direct blow or
impact
 Damage to small capillaries in tissue
 Local bleeding (hemorrhage), causing
ecchymosis (discoloration of tissue), may be
immediate or delayed
Contusion Severity
• First degree: superficial damage, minimal swelling,
localized tenderness, no limitations to strength or ROM
• Second Degree: Increased pain and hemorrhage,
increased area and depth of tissue damage, mild to
moderate limitation sin ROM and muscle function or both
• Third degree: severe tissue compression, severe pain,
significant hemorrhage and development of hematoma
• Significant limitations in ROM and muscle function
• Suspect damage to deeper structures such as none
Closed Wounds

Sprains: injury to ligaments or capsular structure
 Ligaments attach bone to bone
 Injury occurs when 2 bones separate or go beyond normal
ROM
 First Degree: mild overstretching
 Mild pain and tenderness, little or no disability
 AROM and PROM not limited but some pain at end range
 Firm definitive end point (feel)
 Degree of swelling and discoloration not great indicator of
severity
Sprain Severity
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Second Degree: Further stretching and partial disruption or macro
tearing of ligament
 Moderate to sever pain
 Point tenderness
 Eccyhmosis
 Swelling
 ROM and normal function limited secondary to pain and
swelling
 Stress testing shows instability or laxity but still feel an end point
Sprain severity

Third Degree: Complete disruption or rupture or loss of ligament
integrity
 Associated with feeling or sound of a pop
 Immediate pain and disability
 Rapid swelling. Eccyhmosis and loss of function
 Stress test shows moderate to severe instability with no firm end
point “ soft or mushy”
 Can be deceiving because Rom and stress testing less painful
because ligament not intact
Strains

Stretching or tearing of muscle or tendon
 Violent, forceful contraction or overstretching
 Fatigue, lack of warm up muscle strength imbalance,
and dyssynchrony
Strain Severity

First Degree: overstretching and micro tearing of
muscle or tendon.
 No gross fiber disruption
 Mild pain and tenderness
 Typically full AROM and PROM
 Pain with resisted muscle contraction
Strain Severity

Second Degree: further stretching or partial tearing of
muscle or tendon fibers
 Immediate pain, localized tenderness and disability
 Varying degrees of swelling, eccyhmosis, and
decreased ROM and strength
 Pain with active muscle contraction and passive
muscle stretch
 May have palpable defect
Strain Severity

Third Degree: Muscle or tendon completely ruptured
 Audible pop
 Immediate pain and loss of function
 Palpable defect on superficial muscles
 Muscle hemorrhage and diffuse swelling
 ROM and strength may or may not be affected or
painful
Injury Classifications

Open (Exposed) Wounds
 Injuries that involve disruption of the skin
 Caused by friction or blunt or sharp trauma
 Susceptible to infection
 Monitor for pus increased pain, redness, swelling,
heat and red streaks running from wound to trunk
 If signs of infection are present refer to medical
professional
Injury Classifications

Bone and Joint Injuries
 Closed Fractures: disruption in continuity of bone without disruption of
skin surface
 Traumatic (Acute): immediate pain, rapid swelling, bony tenderness,
false joint, crepitus, deformity
 Displaced fracture concern with secondary injury
• Evaluate neurovascular status distal to fracture
site

Stress Fracture:
 S & S not always as obvious
 Onset of pain is gradual
 Pain or deep ache may be first noticeable during activity and subside
with rest,
• progresses to more constant pain if offending activity
continues

Swelling is minimal and localized tenderness over fracture site
Bone and Joint Injuries



Epiphyseal Injury
 Disruption of epiphysis or epiphyseal plate (growth plate)
 Can cause premature closing and growth abnormalities
Dislocation
 Complete disassociation of 2 joint surfaces
 Forces cause joint to exceed passed its normal ROM
 Severe Stretching or complete disruption of joint capsule and
supporting ligaments
 Pain swelling, loss of function, deformity
Subluxation
 Incomplete disassociation of 2 joint surfaces
 Disability, pain, selling and joint instability varies
 Often history of sensation of joint slipping or giving out
Injury Classifications
Nerve Injuries
Nerve Injuries

Compression or tensioning of
neural structure

Laceration of nerve can occur
secondary to fracture, dislocation,
penetrating trauma

Anesthesia: no sensation

Parathesia: tingling, burning,
numbness

Hyperesthesia: hypersensitivity

Paralysis: complete loss of muscle
function

Neuropraxia: transient and reversible
loss of nerve function

Axontmesis: partial disruption of
nerve
 Considerable atrophy and weakness
due to prolonged healing 2 weeks
to a year

Neurotmesis: most severe nerve injury,
complete severance of the nerve

Neuralgia: achiness or pain along
distribution of nerve secondary to
irritation or inflammation

Neuroma: thickening of a nerve or
“nerve tumor”, secondary to chronic
irritation or inflammation