Unit 3 - Kinematics of Trauma and Risk Envelope Analysis

Inertia

Inertia

Fundamental property of matter that describes the resistance to any changes in velocity (speed and direction); a function of mass

Mass

A physical and fundamental property of matter

• Creates gravitational interactions, responds to energy, has inertia

Motion

Matter changing position over time; recorded as how far an object goes in a given amount of time

w/o reference to direction is speed motion = distance = r/t

Velocity

Unit of speed in a given direction Can be represented as a vector

Energy (potential and kinetic)

Potential: the ability to do something (stored energy) Kinetic: energy of moving objects

Starting PE + KE = Ending PE + KE

Acceleration

Changes in speed or direction over time; change in velocity

• Requires a force acting on a mass to change how that mass is moving

Force

Unit of mass times acceleration (F=ma)

• “Force of impact” is acceleration of mass over a time or distance

• The faster this delivery of energy, the greater the resulting energy

D-stop

Distance to stop

Pressure

Force over an area (P=force/area) The more concentrated the force → the higher the pressure → the greater damage Given in lbs/in2 or newtons/m2

Power

The unit of force acting over a distance per unit of time

• given in watts

Rotation

The act of moving around a point in an elliptical path (circles are special ellipses) There are special forces acting on a rotating mass

Momentum

Inertia in moment (resistance to a change in velocity) A function of mass and velocity (“On the move” and “hard to stop”)

Law of Conservation of Energy

Energy cannot be created or destroyed, it can only change form; balance between kinetic & potential energy

Law of Inertia

Mass that is moving (or rest) will stay moving (or rest) unless it has a net force acted upon it

Law of Action and Reaction

Every action has an equal and opposite reaction. If a player runs into a stationary player, the runner and the blocker both exert a force on one another

Energy always has a point of ________ and a point of ________. Why?

Energy always has a point of entry and a point of exit

Why? – energy cannot be destroyed, the energy of an impact must be transferred to another part of a system

Point of Entry / Impact

Area (not a single point) on the body that interacts with the other person, surface or equipment, all the energy transfers occur here (energy entry point)

Keep in mind: any padding or armor, the area of entry, physiology under the point of entry, angle of the forces at the point of entry

Point of Exit

Final point of dissipation of the energy as it leaves the body (usually the feet), when the entire body is taken as a complete system

Keep in mind

• Surface of exit

• Area of exit

• Physiology interacting with the point of exit

• Angle of the forces at the point of entry

Dissipation

Energy changing form and leaving the system

How is energy dissipated?

Heat – friction between different components, breakdown of biological structures

Maco Biochemical – movement of tissues and organs within the body and the body itself along with the disruption of macro processes (think heartbeat and breathing)

Micro biochemical

Define structural capacity and some elements

Each organ, tissue, cell, process, and micro component has a capacity of how much energy it can take before it breaks

• Compression

• Tension

• Torsion

• Heat

• Cold

• Conduction

• Cavitation

• Boundary Integrity

How much impact to the brain can generate concussion systems?

35-45kw OR a single 5kw impact over one second

What is power (in terms of energy)?

Measuring the dose of energy that a body, or organ, receives (ex; dose of advil means a certain amount of energy over 5 hours)

What happens to an organ if it surpasses its boundary integrity / structural capacity?

It will break down

Cavitation

A permanent or temporary separation of tissue, organ, or potential cavity

• If any energy is put any system, there is possibility of cavitation

Temporary cavitation vs Permanent cavitation

Temporary: short lived cavity produced by stretching of the tissues

Permanent: area left behind after the temporary cavitation

What are some factors of cavitation?

Elasticity Density Shape of impactors Angle of impact Cellular integrity Solid of hollow organs

Kinematic stress is...

Below grade 1 stressE

Elastic stress includes...

Torsional, compressive, tensile, bending stresses Overcomes one structural capacity Grade 1

Partial failure

Plastic deformation Substantial tear (bruising) Grades 1 and 2

Complete failure

Complete destruction Grade 3+ Can be repaired with surgery

Strain vs Sprain

Strain (t) = tendons and muscles Sprain (p) = ligaments

What drives impacts (x2)?

impacts are driven by the masses and velocities involved

What are things that factor into damage?

Combined amount of energy Area of impact Time over which the impact dissipates D-stop: the distance over which the impact dissipates (distance from point of impact to point of rest)

What can lessen impact?

Level of impact can decrease if (1) the sum of forces are decreased and (2) the area/distance over time which it dissipates over is reduced

Describe vector arrows

Vector (arrow) is the magnitude of the force Direction of vector is the angle of the force Magnitude: the number/amount, how big/small a force is

Vertical components of impact

Ev = mgh (in Joules, J) F = Ev/Dstop (in Newtons, N)

where... Ev = energy in the vertical direction (N) m = mass of the object (kg) g = gravitational acceleration (9.81 m/s) h = height of the falling object (m) F = force Dstop = the distance over which the object should come to a stop (m

Horizontal components of impact

Eh = 0.5mv2 (in Joules, J) Fh = Eh/Dstop (in Newtons. N)

where... Eh = energy in the horizontal direction (N) m = mass of the object (kg) v = velocity of the object (m/s) at the start of the impact F = force Dstop = the distance over which the object should come to a stop (m)

What parts of the body are considered springs? By what means?

Springs, Bones, Ligaments, and Tendons are SPRINGS; they are able and usually deform under activity

Elasticity

the ability of an element to return to its original shape after deformation (can compress, twist, sway)

Why do bones break?

Bones break when there is too much force and it cannot deform enough

Has an elastic, plastic, and ultimate failure point

• Cross sectional area, mineralization, osteocyte (bone turnover cells) distribution

Describe a bone's cross sectional area

Ligaments and tendons are stronger than bones if the pressure is linear = strings, slow stretched

Bigger, more dense cross section → more energy needs to go through it for a bone to break

Smaller cross section → less energy needed to go through for a bone to break

Describe bone mineralization

Amount of calcium is needed for mineralization until age 5 and after 65 (determines bone capacity)

Describe osteocyte (bone turnover cells) distribution

Osteocytes protect the bones If the distribution is uneven, wherever there are less osteocytes is a weaker section of the bone

• In most people the osteocyte distribution in bones in normal

At what level of a trauma center should athletes be evaluated at?

Unless location really demands it, ALL ATHLETES SHOULD BE EVALUATED AT A LEVEL III OR HIGHER TRAUMA CENTER

Level V center

Rural, remote clinic style facilities NOT A TRAUMA CENTER IN OUR AREA

Provides extremely limited evaluation, resuscitation, and operative interventions to stabilize a patient

• Minimum requirements MD/DO, RN, ER Tech, X-Ray

Complex cases (anything greater than stuffy nose) a should be sent to higher level immediately

Not open 24 hours a day (they have a closing time; 9am-5pm) ex; resorts, rural areas

Level IV center

Found in areas where there would be substantial delay to receive care at a level III

Capabilities:

• Provides limited evaluation, resuscitation and operative interventions to stabilize a patient

• Minimum requirements MD/DO, RN, ER Tech, X-Ray, basic lab, and operating suite (operating room that does not get used); varies widely

• Complex cases should be sent to a higher level immediately

Not a hospital, they are a rural clinic Emergency room is open 24 hours a day, 7 days a week

Level III center

• Real hospital * Found in standard hospitals that service a community, may be several in any geographic area supported by a Level I or Level II 2 Psych beds

Capabilities:

• Provides evaluation, resuscitation, and operative interventions to stabilize a patient

• Most specialities available at most times, some on call. - Every specialty is on call for 45 minutes.

• Complex cases should be sent to Level 1 or Level 2

Level II center

Sub-regional comprehensive care centers Found in large hospitals that will take patients from other hospitals (Level III hospitals send their patients to Level II hospitals)

Capabilities:

• May be missing some level 1 facilities but typically include service from prevention through rehabilitation

• All specialities available at all times

• Able to manage complex cases however, some very complex cases might need to be sent to Level 1

• Leader in trauma care for a given geographic area

Research and education are not a core component but fellowship is common

Psychiatric wing

Level I center

Found in large university hospitals that are actively involved in research and teaching Have students in every single department (whether you’re a med, nursing, paramedic student etc)

Capabilities:

• Everything is available here 24 hours a day

• Medical education is a core component

• Full service from prevention through rehabilitation

• All specialities available at all times

• Able to manage complex cases

• Leader in trauma care for a given geographic area

Medical education a core mission

Two main factors that differentiate a Level I center from a Level II center are…

Education and Diagnostics

• diagnostics: you are presented with a patient and no one can determine what’s wrong with them, so you are the one trying to figure out what is wrong with the patient (must be the best of the best in your speciality)

Blunt force trauma

When the skin is not broken, but has potential for devastating injury

Blunt force trauma is governed by ________ and ____________

Blunt force trauma is governed by SHEAR and COMPRESSION

Describe shear and compression

Shear = difference in velocity between two impactors (acceleration and deceleration)

Compression = force directly applied to the organ; includes time, energy, and area

Types of blunt force trauma

Human vs human (fist to the face, tripping over yourself) Human vs equipment (baseball bat) Human vs surface (falling into ground) Blast Motor vehicle impact (MVI)

What are TIPs?

TIP = Trauma Impact Pathways

Describe what typical down/under TIPs vs typical up/over TIPs (and what down/under vs up/over mean)

Typical down and under TIPs: Lower extremity Fx Pelvic Fx Femur dislocation Bladder, kidney, intestinal damage Lower spine Fx

Typical up and over TIPs: Skull Fx Upper spine Fx damage Brain injuries Thorax injuries

Whiplash

The brain slamming into the front and back of the skull Coup → contrecoup

Axial loading injury What causes axial loading injuries?

Force directed through the top of the head and through the spine (may result in a Fx/dislocation of one or more of the cervical vertebrae)

Causes: vertical falls (feet or head first)

• Height of fall (energy of impact)

• Surface impacted

• Angle of impact

• Distance to stop (Dstop)

• Crumpling of the body

Primary blast injuries

Direct injuries from the shockwave Travels at the speed of sound

Type of injuries: rupture of membrane, tearing of the hollow organs, shearing shredding of the solid organs, and concussive effects on the brain upto and including diffuse axonal injuries

Secondary blast damage

Impact of fragments: little small fragments and missiles carried/kicked up by the blast wave (ie; twigs, rocks, object close to the bomb)

• sizes and shape will be random

Types of injuries: penetrating or lacerating trauma, amputations (from shards traveling at high speeds, power and forces)

Tertiary blast damage

Big wave propels body into objects or large objects strike body Large objects that are sent into the air and strike the patient → causes severe blunt force trauma; CRUSHING injuries

Also, a body might be sent in the air or into motion and strikes a wall, ground, or other object

Quaternary blast damage

Environmental contamination from the device

• Encompasses trauma that is not caused by the object but by fires, chemical reactions on the body surface, or the contamination of words

Radiation trauma from a pulse wave is NOT considered quaternary blast damage, but primary

Quinary blast damage

Bodily absorption of device additives (toxic effects of products of the chemicals used in the explosion)

Penetration vs Puncture

Penetration: any trauma where an object enters the body

Puncture: any trauma where an object enters the body and does not exit; either no exit wound or object remains in body and communicated with outside

• All punctures are penetrations and not all penetrations are punctures

What impact does angle and depth have on an injury?

Angle and Depth have a huge impact on the damage of a blow

• Perpendicular penetration is devastating and can compromise the lungs and the heart

• No angle over 30° could miss the lungs entirely

• If the penetrator has been removed it is not able to be 100% sure of the angle and depth of the penetration

GSW stands for...

Gun shot wound

Temporary vs permanent cavitation via GSW

Permanent cavitation is formed by the path of the bullet

Temporary cavitation is formed by the tissue blown outwards from a pressure wave, causing compression injuries or tearing surrounding the wound

What factors determine cavitation in a a GSW? describe

Mass Ballistics (path/trajectory of bullet) Deformation of bullet (will it deform upon impact?) Spin Tumble (can create a bigger cavitation) Fragmentation

What can ramp up damage in a GSW?

“More effective” to ramp up velocity > mass (ex: small bullet with a higher velocity is more dangerous than a large bullet with a lower velocity)

What is needed if you want to train in a specific sport?

Knowledge of TIPs with an understanding of the physics involved in the pathway

Knowledge of the flow of the games and practices (what is likely to happen)

Knowledge of the physiology of the elements of the TIP

Combat levels - how are they determined?

• How often do you get touched in your sport?

• determined by the level of person to person contact (not the overall energy of the plays, not player vs equipment, surface, or ball)

Combat / Full Contact Band (CFC)

Player to player interactions are an integral of practice and play (ie; football, sideline and performance cheer/stunt, dance)

Incidental Contact Band (IC)

Player to player contacts may be common but are considered a foul or not a regular part of each play (ie; basketball, soccer, volleyball, baseball, softball, cross country)

Noncontact Band (NC)

Player to player contact is not possible or part of play (ie; golf, tennis, track and field, swim)

How are risk ratings determined?

LIKELIHOOD, SEVERITY, COMPLEXITY

• energy levels, fall height, complexity of rehab, complicated training and intense rehab needs

High risk sport

High force / full speed impacts are likely Falls over two meters are likely Catastrophic injured to multiple systems Complicated training and intense rehabilitation needs

Medium risk sport

High force / full speed impacts are possible but rare/unlikely Falls are limited to under 1 meter or standing Catastrophic injuries are possible but unlikely Rehabilitation needs are usually straightforward

Low risk sport

High force / full speed impacts are very rare or impossible Falls are limited to standing or running Catastrophic injuries are extremely rare Most injured athletes need only straightforward rehab needs

When developing risk envelope analysis, trainers must…

Understand the RULES of the sport Understand the PLAYS (sometimes better than the players!) Understanding the PRACTICE (practice culture)

Steps to developing risk envelope analysis

Determine the contact band Determine the risk band Determine the coaching evaluation Understand the rules, plays, practice Determine the operational requirements Combine the four determinations

Pathway

A common route of energy / movement in each impact

• You have to understand the energies, forces, and how those are generated or what they are affected by

Risk rating per pathway fraction

Likelihood (numerator) vs Severity (denominator)

Likelihood 10-8 often; expected each season 7-5 rare; expected each career 5-2 unlikely; expected across each team career 1-0 rare; expected few times across all of the sport

Severity 10-9 career ending 8-6 season ending 5-4 at least 3 week rehab 3-2 at least 1 week rehab 1-0 at least one day rehab

Tort Law

Disagreements between individual citizens Based on negligence, must have caused actual harm (property or personal damage) Also includes contract and business law

Criminal Law

Infractions of a citizen against society (the public good) “The people versus John Doe” Based on criminal statutes Harm to society Mens Rea

Mens rea

Having the metal state with intent to do harm

What are the 3 types of law? Describe

Statutory law – anything passed by legislature

Administrative law – law created by governmental agencies that carry out laws passed by legislature

Common law – courts; derived from judicial decisions instead of from statutes

Stare Decisis

(Let the Decision Stand) When a court faces a legal argument, if a previous court has ruled on the same or a closely related issue, then the court will make their decision in alignment with the previous court's decision.

Who has Stare Decisis?

State superior court – common law for county State supreme court – common law for state Federal district court – common law for federal district Federal circuit court – common law for states in circuit Federal supreme court – common law for the U.S. (all)

Defendant vs Plaintiff

Plaintiff = person making the claim and has the burden of proof

Defendant = person defending against the claim and may refute the statements

Negligence

A situation in which a person acts in a careless (or "negligent") manner, resulting in someone else getting hurt or property being damaged

What are the 3 types of Negligence? describe

NONfeasance

• Failure to do something that was required by a duty to act

• “Didn’t know you had a duty”

• No mens rea

MISfeasance

• Attempting to adequately do one’s duty and making an error (no ill will)

• “Honest mistake” – No mens rea

• Should have understood the correct way to carry out the order

MALfeasance

• Understanding the correct way to carry out the duty and purposefully doing the wrong thing to harm the defendant

• Must prove Mens Rea (difficult to prove)

• Usually criminal as well as Tort

What are the requirements of Negligence?

Duty to act

• Must have a legal obligation to act in a certain way

• Abandonment

• "Protect the public"

• Removal of attractive hazards since “you can’t entice people to crime”

Breach of duty

• Omission

• Screwing up, didn't know what suposed to do

Cause in fact

• "Without this..."

• Cause of harm done to plaintiff

• Sine qua (essential)

Proximate cause

• “Causa proxima”

• Closest cause that was foreseeable to the harm

Monetizable harm

• Must have $$ value

• The cost of making the plaintiff whole

• "Judgment proof” (ex; kids, but may be transferred to parents)

• If not able to be monetized, then not able to be ordered to repay

Cost of a person

Person’s wages x [the number years until they reach 65 y/o aka retirement age] since 65+ y/o do not have value to society

Creation of a duty to act

Once you understand you have a duty, you must act in accordance to it; you should be worried about what you hear and see (AKA burden of knowledge)

When must you act when burden of knowledge is piqued?

Duty to act is IMMEDIATE

Preservation of evidence

Everything is discoverable (even after you "delete")