1

Transportation injuries Presented

by

Dr. Said Kamal

Agenda1. Introduction2. Risks factors of traffic accident 3. The dynamics of vehicular injury 4. Pattern of injury of vehicle occupants 5. Cause of death in traffic accidents6. Injuries to pedestrians7. The effect of seatbelts 8. The vulnerability of children in vehicles 9. Injuries to motorcyclists 10. Injuries to pedal cyclists.11. Railway injuries12. Aircraft disasters.13. Ferryboat accidents

Transportation accidence: are occurrence of sequence of events which usually produces unintentional injuries or death during transportation.

Transportation trauma: is a complex of mechanical lesions produced by the external or internal parts of a moving transport unit, just as the fall from it.

1- 3,400 people die on the world's roads / day. one death / 26.3 second

2- 20-50 million are injured or disabled every year. 15 injuries/second

3- Children, pedestrians, cyclists and the elderly are the most.

4- Males aged 15-44 years the most exposed to road traffic injuries.

5- The 2nd leading cause of premature death (behind HIV/AIDS) worldwide.

6- 11th leading cause of death globally.

7- Responsible for 2.2% of annual global deaths.

http://www.cdc.gov/ncipc/pub- res/research_agenda/06_transportation.htmWorld Health organizationReport 2004.

Public transportation "common carriers." TaxisBusTrainsPlaneFerriesTrolleys Elevators Escalators المتحركة الساللمMovable walkwaysAirport shuttles

- Light vehicles: cars and light vans under 1.5 tonnes- Heavier vehicles: trucks and buses.

I. Terrestrial: •Wheeled: a) rubber (cars, buses, motorcycles, trucks, tractors, etc.) b) Metal (train, tram); •Without wheels: a) caterpillar (tractors, armored) b) without caterpillars or wheels (escalators etc.).

II. Underground: (the same as terrestrial) III. Aviation: •Propeller (aircraft, helicopter); •The jet engine (airplane); •Without motor (flying-plane).

IV. Naval: •Aquatics •Underwater

Classification of transport units

Risks factors of traffic accident :

Injured person Psychological factors: lack of experience, risk taking, defective judgment, delay in decision making, poor perception, family dysfunction.

Medical factors: sudden illness, heart attack, impaired vision, hearing and fatigue, alcohol, myocardial infarction, diabetic coma or drug intoxication.Failure to follow regulations Aggressive driving behaviors: reckless driving Cell-phonesDriver negligence Seat-belts and child restraints not used

VehicleDefective equipmentImproper maintenanceInadequate safety measures

Environment:Weather conditionsDangerous roadways

In transportation- related death , the postmortem examination is performed 1- To establish the identity of the deceased (especially in burned, charred or mutilated body)2- To determine the actual cause of death and whether or not death was due to the vehicular mishap,3- To determine the extent of injury, any contributing or precipitating factor(s).4- To document findings for possible use in criminal or civil proceedings which may follow

Frontal impact

Rear impact

Rollover

Front to side impact

Pedestrians

Seatbelts

a)specific to a concrete type of trauma b)characteristic (depend on the mechanism of a concrete type of trauma)c)uncharacteristic (may be in all conditions of mechanical trauma) d)simulated (they look far from blunt trauma)

Classification of transportation injuries

Classification of car trauma Trauma due to automobile collision with pedestrian •Trauma by crossing with car wheels •Trauma in the interior of the car •Trauma due to falling from car •Trauma by compression between car parts and other objects or obstacles •Combined trauma

1- Tissue injury is caused by a change of rate of the movement. A constant speed, however rapid, has no traumatic effects. The traumatic injuries occur always in acceleration and deceleration

2- Change of rate measured in 'gravities' or 'G forces'. The amount that a human body can tolerate depends greatly on the force direction and it depends upon the force applied per unit. Formula: G = C(V2)/ D where, V is velocity in km/hour, D is the stopping distance in meters after impact C is a constant 0.0039.

3- Between 60 - 80 % of vehicular crashes are frontal, 6 % are rear impacts, 0.5 % are sideswipes and the rest 'roll-overs'. (knight, 1996).4- The pattern of injury varies according to occupant position.5- Heavy goods vehicles suffer less than cars and light vans because of their far greater mass and strength.6- Structural damage from impact with other smaller vehicles is less because it is sustained below the level of the driver.

The dynamics of vehicular injury

The driver in front impact1- The unrestrained driver first slides forwards so his legs strike the parcel-shelf area.

2- The abdomen or lower chest contacts the lower edge of the steering wheel.

3- The body then flexes across the steering wheel and begins to rise.

4-The heavy head goes forwards, and there is flexion of the cervical and thoracic spines.

5-The upward and forward component causes the head to strike the windscreen, the upper windscreen rim or the side pillar

6-The windscreen is often perforated by the head or face, and the whole body may be ejected through the broken glass, to land on the roadway ahead.

Major points of injury to an unrestrained driver of a

vehicle in deceleration impact

Pattern of injury of vehicle occupants:

1- Be ejected through the broken glass to the land.2- Intrusion of structural parts into the passenger compartment.3- The engine or front-wheel assembly may be forced back into the seating area, intruding upon the driver. 4- The roof (the so-called 'A'-frame) may cave in on top of the driver.5- One effect of column, engine, or gearbox intrusion may be to force the floor up and backwards against the driver's feet and legs.6- The control pedals intrusion, and the reflex pressure of feet on rising pedals and floor may cause transmitted force up the legs and into the pelvic girdle. 7- The steering column is a more dangerous item for intrusion, being forced back to 'stab' or crush the driver's chest or abdomen. the wheel itself breaking and penetrating the chest. 8- The door may burst open and the driver may ejected sideways

Transportation injuries

1-Bruising, laceration and bilateral leg fractures of a car driver in a frontal impact.

2- Severe internal injuries. Laceration of the skin is rare unless the steering wheel snaps and penetrates the trunk.

3-Other steering-wheel lesions include bruising of the lungs, fractured ribs and sternum, cardiac contusion and haemothorax or pneumothorax or both.

4- Upper limb injuries are less common but may occur from transmitted force through gripping the steering wheel or from impact against the windscreen when held up in a reflex protective position.

Head and spinal injuries

Head Injuries1- Abrasions and bruises: Bruises may shift downwards causing a “black eye”

2- Lacerations: impact strikes the skull by the windscreen. Avulsion of a large area of scalp, can be torn from the head, thereby exposing the aponeurosis or skull where a rotating vehicle tyre comes into contact with the head, causing a 'flaying injury.

3- Facial injuries: Lacerations of the prominent parts (e.g. forehead, eye-brow, nose, chin) -Black eye may occur due to either: direct trauma to the eyes or indirectly by:

Gravitation of blood from higher levels in the body Percolation of blood in case of fracture base of skull (ant. Cranial fossa)

1- Windshield and side window glass cause characteristic injuries. A windshield is composed of two pieces of glass bonded together with plastic.

2- Side windows are made of tempered glass which shatters during impact into numerous small fragments. These fragments cause a characteristic "dicing" pattern of lacerated-abrasions on the face, shoulders, or arms.

3- Observation of this pattern is one method of determining an occupant's position. A

driver has dicing injuries on the left side of his body and a passenger has them on the right.

4- The face‘ frequently suffers multiple cuts from contact with the shattered safety glass. In most European vehicles the glass is of the toughened, not laminated, variety and, when broken, it shatters into small cubes with relatively blunt edges. These still cause superficial lacerations, often in short 'V-shaped' or 'sparrow-foot' patterns.

5- Hyperflexion of the cervical spine when the head swings can cause fractures or dislocation. The atlanto-occipital dislocation, - Other fractures can occur anywhere in the cervical spine, often at about C5-6. dorsal spine, often around T5-6-7. 6- Skull Fractures: Three main factors affect the type of skull fracture: Severity of the force

Size of the striking surfaceMovement of the skull

Comminuted fracture : More common with wider impact to skull, accompanied by tearing of vessels and/or brain lacerations

Hinge fracture : Affects base of skull separating it into two halves . May associated with brain stem into the foramen magnum herniation

7- Subdural bleeding:Arises from shear stresses in the upper layers of the cerebrum, which moves the communicating veins laterally sufficiently to rupture their junctions at either the cortical veins or the sinus surfaces. Subdural bleeding is most often over the lateral surface of a cerebral hemisphere, high up in the parasagittal area.

- As with most intracranial damage, cause is a change of velocity of the head, either acceleration or deceleration, almost always with a rotational component.

- Where a blunt impact strikes the skull, the subdural bleed need not be situated directly under the impact area - it need not even be on the same side of the head. It is sometimes tempting to attribute a localized subdural to either a 'coup‘ or to a 'contrecoup' effect

8 -Concussion An injury to the head causes the brain to

bounce against the rigid bone of the skull. This force may cause a tearing or twisting

of the structures and blood vessels of the brain, which results in a breakdown of the normal flow of messages within the brain.

Less damage nerves can repair themselves.

More severely damaged nerves lead to swelling and disintegration of the nerve.

Grade 1 The mild concussion occurs when the person does not lose consciousness (pass out) but may seem dazed.

Grade 2 The slightly more severe form occurs when the person does not lose consciousness but has a period of confusion and does not recall the event.

Grade 3 The classic concussion, which is the most severe form, occurs when the person loses consciousness for a brief period of time and has no memory of the event.

Forensic anatomy- The two vertebral arteries arise from each subclavian behind the sternoclavicular joints.

- Each artery ascends behind the common carotid to reach the transverse process of the 6th cervical vertebra.

-Then enter the foramen in that process and passes upwards through each similar foramen until it emerges from the upper edge of the second (axis) vertebrae.

-Then bends laterally and enters the final foramen in the atlas vertebrae.

-Penetrates the posterolateral aspect of the atlanto-occipital membrane and the underlying spinal dura and arachnoid, emerging on the lateral side of the spinal canal just below the foramen magnum.

- Both arteries then ascend and converge on the ventral surface of the medulla and pons to fuse in the midline to become the basilar artery.

Spinal cord ends with a bulb like structure

(conus medullaris) between L1 & L2

Cauda equina (Bundle of nerver fibers) starts at

L1-L2 level

In a rear impact1- The driver is violently

accelerated and, if no rigid head restraint is fitted to the seat, severe hyperextension of the neck occurs, often followed by the sequence of deceleration events when the car is cannoned into the vehicle or other obstruction in front, causing the 'whiplash'. injury

2- Definition : Whiplash is an acute injury caused by a strain to the bones, muscles, nerves, tendons, and vertebral discs of the neck region results from a sudden, unexpected impact which jerks the head back and then forward causing the neck to snap out of alignment.

Bones

2- Bilateral Facet Dislocation

Flexion injury

Subluxation of dislocated vertebra of greater than ½ the AP diameter of the vertebral body below it

High incidence of spinal cord injury

crushed

All four phases of a whiplash injury occur in less than 1/2 second!

Phase 1 : During this first phase, the car begins to be pushed out from under the driver, causing his mid-back to be flattened against the back of his seat.

This results in an upward force in his cervical spine, compressing his discs and joints.

As the seat back begins to accelerate the driver's torso forward, his head moves backward, creating a shearing force in his neck.

-If the head restraint is properly adjusted, the distance that the head travels backward is limited. However, head restraints only reduce the risk of injury by 11-20%.

Phase 2

The driver's torso has reached peak acceleration - 1.5 to 2 times that of the vehicle - but his head has not yet begun to accelerate forward and continues to move rearward.

An abnormal S-curve develops in cervical spine as the seat

back recoils forward, much like a springboard, adding to the forward acceleration of the torso.

Unfortunately, this forward seat back recoil occurs while the head is still moving backward, resulting in a shearing force in the neck that is one of the more damaging aspects of a whiplash injury.

Many of the bone, joint, nerve, disc and TMJ injuries that occur during this phase.

Phase 3

Driver's torso is now descending back down in the seat and the head and neck are at their peak forward acceleration.

At the same time, the car is slowing down. If the driver

released the pressure on the brake pedal during the first phases of the collision, it will likely be reapplied during this phase.

Reapplication of the brake causes your car to slow down even quicker and increases the severity of the flexion injury of your neck.

As moving forward in the seat, any slack in the seat belt and

shoulder harness is taken up.

Phase 4 This is the most damaging phase of the whiplash phenomenon.

The torso is stopped by the seat belt and shoulder restraint and

the head is free to move forward unimpeded.

This results in a violent forward-bending motion of neck the,

straining the muscles and ligaments, tearing fibers in the spinal discs, and forcing vertebrae out of their normal position.

The spinal cord and nerve roots get stretched and irritated, and

the brain can strike the inside of the skull causing a mild to moderate brain injury.

If the driver are not properly restrained by the seat harness, he

may suffer a concussion, or more severe brain injury, from striking the steering wheel or windshield.

Whiplash traumaAbout 12% of persons who suffer from whiplash are symptom-free after 10 years of the accident.

Neck Pain and stiffnessHeadaches/migrainesTemporo-Mandibular Joint (TMJ) problemsBrain InjuryDizziness Low back pains and hip pain,Nausea/vomiting Problems thinking or remembering Numbness and tingling (arms, face, shoulders)Impaired vision

Common sites for fracture

C7-T1 junction

T12-L1 junction

SCIWORASpinal cord injury without radiological abnormality

Common in children

Spinal Injuries

Spinal Column Injuries

Injuries to Neural Structures (spinal cord, nerve roots)

±

3 .Cervical Fracture- Cervical fractures usually result from high-energy trauma, such as automobile crashes or falls. - Any injury to the cervical vertebrae canhave serious consequences because the larger percentage of the spinal nerves run through the center of the vertebrae

-Injury to the spinal cord at the level of the cervical spine can lead to temporary or permanent quadriplegia, paralyzing the entire body from the neck down.

4. Axial LoadingWhen the neck is slightly flexed (30°), the vertebra line up in a linear (straight) fashion. Under this alignment, the force is absorbed entirely by the bones ligaments and disks, rather than the muscles. This is called axial loading.

Axial loading is now recognized as the primary cause of injury although flexion-rotation, hyper-flexion, or extension may produce significant injuries.

5 -Compression Fracture Injuries may occur at speeds as low as 8-9 miles / h. Most common injuries at C4-C6 but higher in older individuals

6- Neurogenic Shock Temporary loss of autonomic function of the cord at the level

of injury results from cervical or high thoracic injury

Presentation Flaccid paralysis distal to injury site Loss of autonomic function

hypotension vasodilatation loss of bladder and bowel control loss of thermoregulation warm, pink, dry below injury site Bradycardia

Chest (Lung and heart)

Chest Injuries1. Injuries to chest wall.

2. Heomorrhage and infection in the chest.

3. Pneoumothorax (types-causes-complications)

4. Injuries to the lung

1. Injuries to the heart.

2. Hemopericardium and cardiac tamponade.

3. Injuries to great vessels.

HemothoraxPneumothorax Bronchopleural fistula

Injuries to the chest wall Fracture ribs(single – multiple ) Flail chest(frontal violence or

stamping assaults)

Injuries to the lung1. Bruising of the lung: In open and closed chest injuries. Site : Occurs at area of impact or contrecoup. Deceleration injuries: Posterolateral surfaces “vertical

line of subpleural bruising” in the paravertebral gutter. Rib imprints. If severe contusion : Subpleural blood blisters, rupture

to release blood or air into the pleural cavities.

2. Laceration of the lung: “ as in blunt injuries.” Lobes or parts of a lobe may be detached. The hilum may tear." hemorhage into pulmonary

ligament” Vessels in the hilum may be ripped.”pulmonary veins”

Injuries to the lung cont.

3. Penetrating injuries of the lungs : commonly results from the steering column that introduced, and being forced back to 'stab' or crush the driver's chest or abdomen.

4. Blast injury: the lungs are the most vulnerable organs to this type of injury due to the large tissue-air interface.

5. Sternal and rib fractures : Other chest injuries due to impact with the steering wheel, ejection through the windscreen or impact with the road.

-There may be bruising or laceration on the chest from the

steering wheel, though padding, collapsible columns. Beneath the skin, sternal and rib fractures ± flail chest are

common, though fatal visceral injuries can occur without rib fractures in young people because their ribs are more pliable.

6 -Fractures of ribs Fractures of ribs are common, but do not greatly restrict

respiration unless:

1. They are so numerous that they prevent expansion of the thorax.

2. Broken ends penetrate the pleura and lungs.

3. Pleural and muscular pain limit respiratory effort.

7- Flail chest The condition of flail chest presents with multiple fractures of

some ribs ± fracture(s) of the sternum. The loose section is sucked inwards during inspiration, this

clinical sign being known as “paradoxical respiration”.

Extreme degrees of flail chest are rapidly incompatible with life because of progressive hypoxia.

Always caused by frontal violence, as in motor vehicle accidents “ where the victim is thrown against the steering wheel.

8 - Heomorrhage in the chest: Cause: ” Any injury to the chest wall or lung surface that reaches

blood vessels and the pleural lining” Source : ” Intercostal, mammary arteries can bleed into the pleural

cavities, large vessels in the lung or mediastinum → causes massive hemorrhage (the heart is also a source. )”

Complications : ”fatal hemorrhage, Cardiac tamponade, hemothorax

There may be air bullae or blood blisters under the pleura overlying the bruised areas and a pneumothorax or haemothorax may result.

The interior of the lung may be pulped even in the presence of an intact visceral pleura, from transmitted force or massive variations in intra-thoracic pressure during the impact.

The lung often shows areas of bleeding under the pleura, which may be from direct contusion, from aspiration of blood from other damaged areas of lung or from blood sucked down the air passages from injuries in the nose or mouth.

9- Pneumothorax

1. Simple type: where a leakage through the parietal pleura allows air to enter the pleural cavity, but the communication rapidly closes →The lung partly collapses, then the air absorbed.

If the communication remains open, a bronchopleural

fistula results “air is present in the pleural cavity but is not under pressure”.

2. Tension pneumothorax : the leak in the pleura has a valve-like action, air is sucked into the pleural cavity at inspiration, kept trapped on expiration. Causes lung collapse and mediastinal shift.

Pneumothorax

Types

Injuries to the heart

1- The heart is vulnerable to both penetrating and blunt injuries.

2- The frontal surface of the heart is more commonly injured; but also injuries to the post surf .heart are not uncommon.

3- Ruptured aorta a more common injury associated with deceleration. It may be associated with a severe whiplash effect on the thoracic spine, as the aorta is tethered to the anterior surface of the vertebrae where the distal arch joins the straight descending segment.

4- The most common reason for aortic rupture, is the 'pendulum‘ effect of the heart within the relatively pliable thoracic contents.

5- When the thorax is violently decelerated, the heavy cardiac mass attempts to keep moving ahead and may literally pull itself off its basal mountings.

6- Separation takes place at the point where the aorta is attached to the spine at the termination of the arch. Clean-cut circular break, almost as sharp

7- ‘Ladder tears', a transverse intimal tears adjacent to the main aortic rupture.

8- The cardiac injuries are usually on the front of the organ, to the right ventricle.

9- Posterior bruising and laceration “heart is compressed against the thoracic spine”.

10- All degrees of damage can occur, from mere epicardial bruising to lacerations.

11-Completely avulsed from its base in high-speed impacts.

12-Subendocardial haemorrhages on the left side of the interventricular septum is NOT a sign of impact, but an index of catastrophic hypotension.

Abdominal InjuriesLiver1- Ruptured liver : The major abdominal injury may be damaged in any part. 2- Central tearing : A common lesion of the upper surface, which may extend deeply and even transect the organ. 3- Less serious damage : shallow, sometimes multiple, parallel tears on the upper surface of the right lobe.4- Subcapsular tears with the formation of a subcapsular haematoma, which can rupture later.

Spleen5- Shallow tears : in some accidents, often around the hilum; Avulsed from the pedicle.: in rare cases,

6- Mesentery and omentum often show bruising and, rarely, there is laceration and fenestration sufficient to cause a lethal haemorrhage.

7- Almost any kind of injury, usually multiple, may be sustained after ejection, either from contact with the road surface or (in a significant proportion) from being struck by other vehicles, especially on motorways.

The front-seat passenger:The pattern of injuries is similar to that of the driver, but this position in the car is even more dangerous,

1- There is no steering wheel to impact into the chest, its absence also denies the slight protection offered to the driver in reducing the collision with the windscreen, perhaps by giving him something to brace against

2- the driver gives his attention constantly to the road and so has momentary warning of an impending crash, compared with the passenger

Rear-seat occupants:During violent deceleration, unrestrained occupants in the rear are projected forwards and strike the back of the front seats, including head-rests where fitted. They may be thrown over the seats, striking and adding further injuries to the front seat occupants and may even be ejected through the windscreen, which is broken by them or by the people in front.

Ejection is another common cause of death and serious injury in rear-seat occupants, a wide range of head, chest and limb injuries being seen.

THE EFFECT OF SEATBELTS

(a) Simple lap-strap (dangerous to aorta), (b) Diagonal only (can slip underneath),(c) Diagonal plus lap-strap (usual car type), (d) Shoulder harness used in aircraft & racing cars).

Various forms of strap restraints act by:

A)Holding the occupant back against the seat, so that forward projection against the steering wheel and windscreen is prevented.

B)The belt restrains the occupants within the vehicle in the event of a door bursting.

C)Extending the deceleration time and distance by substantial stretching of the belt

D) Spreading the area of application of deceleration forces. The same deceleration diffused against the thorax and abdomen rather than against the skull,

** Seatbelt-use reduces deaths and serious injury by a factor of 20-25% in Australia New South Wales and Britain.

1-Pregnant women with possibility of uterine and fetal injuries

2- Too small persons(child or a small woman), may slide from under the strap (‘ submarining )or it acts around the neck. Below age 14 must be in rear seats in some European laws

3- Loose straps allow the body to move relative to the belt before sudden restraint occurs, decreasing the distance between the passenger and facing structures.

4- Some women find that the diagonal strap compresses the breast, so that the greatly increased tension during deceleration is likely to injure the gland.

5- Incorrectly adjusted or positioned straps such as a twisted belt, which reduces the area of contact, can increase the danger of injury.

6- Bruising is the most common and may be seen either under the diagonal or the transverse component of the three point belt.

7- It is more common with the single aircraft-type lap-strap because of the smaller area of pressure.

Seatbelt injuries

8- Bruising to the abdominal or chest wall, but the dangerous lesions are to visceral.

9- Rupture of the mesentery, or he small or large intestine, usually occurs from acute flexion over a lap-strap.

10- The full bladder can be ruptured as can the caecum. 11- The abdominal aorta can be crushed and the lumbar spine suffer a compression fracture or be dislocated through a disc in the midlumbar region.

12- The posterior arch, pedicles or transverse processes may also be damaged.

13-The diagonal strap usually prevents serious abdominal injury as it prevents hyperflexion, but it may contribute to thoracic injury.

14- Bruising of the skin and underlying muscles and fractures may accompany a broken clavicle or sternum where the belt crosses them.

Seatbelt injuries cont.

Airbags1- A large fabric bag, folded into the steering- -wheel hub in the case of the driver position and into the fascia in front of the front-seat passenger.

2- A sensitive deceleration device triggers the ignition of sodium azide, a solid and highly toxic explosive propellant, which is converted in milliseconds to nitrogen gas.

3- The deploying airbag can reach speeds up to over 300 km/h (>200 mph). Deflation is also rapid, so that residual car control and escape from the vehicle is not impeded.

4- The inflated bag is designed to interpose itself between the occupant and the frontal structures to cushion the impact and prevent forceful contact and hyperflexion.

5- Injuries can be inflected at any stage, depending on the posture and possible objects between the occupant and the deploying airbag or the module cover.

6- They vary from facial bruising, partial or complete amputation of fingers to dislocated and fractured arms or cervical spine and fatal head injuries.

7- Eye injuries are common and range from mild corneal abrasions and chemical burns from contact with unburned sodium azide or the alkaline byproducts of combustion, to globe rupture from blunt trauma or perforation by interposed objects.

Source: http://www.rospa.co.uk/roadsafety/info/adjust_head_restraints.pdf

How can it be prevented?

Mechanisms of production the lesions: a)vehicle collision with pedestrians b)fall the body on the car c)fall the body on the road d)sliding on the surface of the roadway

A- Automobile collision with pedestrian

May by: •Complete •Incomplete (transversal, longitudinal and oblique)

Mechanisms of production the lesions: 1)hitting the body by the wheel 2)pushing the body by the wheel 3)climbing wheel on body 4)crossing the body by wheel

B- Crossing with car wheels

C- Trauma due to falling from car There are three kind of falling from car a) anterior fall b) posterior fall c) lateral fall

Mechanisms of production the lesions: 1) Hit the body by the car parts 2) Fall on the road 3) Sliding on the road

D- Compression between car and other objects

Mechanisms of production the lesions: 1)hitting the body by the car 2)compression the body between the car and objects (obstacles)

Risk Factors For Pedestrian Collision

1- Two primary factors are when and where pedestrian collisions occur. Most fatalities occur between the hours of 6 pm and midnight.

2- Impaired vision among drivers due to the lack of daylight, coupled with pedestrian traffic and alcohol consumption by either the driver or the pedestrian

3- Two-thirds of pedestrian fatalities occur in urban areas and three-fourths occur in non-intersections.

4- Urban areas have a higher rate of pedestrian and motor vehicle traffic. Drivers non-compliant with speed limitations, pedestrian lack of safety awareness, poor city planning and other

Rural areas pose their own unique, significant risks. Although the overall number of collisions is fewer than in urban centers, pedestrian injuries are more severe and are fatal a greater percentage of times in rural settings

 Higher vehicle speeds, lack of proper pedestrian walkways and larger distances to a trauma center likely contribute to a higher mortality rate.

Why? Young Children: Think that if they can see a driver, the driver can see them. They think that cars can stop instantly They can’t tell where sounds come from They can’t judge how fast traffic is moving. They have a field of vision 1/3 that of adults They don’t recognize danger or react to it They think of cars as friendly, living creatures They are also more prone to be run over vehicle and trucks, as they often play between parked vehicles and - being small - are less visible to the driver.

The most common injuries seen in pediatric are traumatic brain injuries and musculoskeletal injuries, the upper and lower legs and knees followed by chest and abdominal injuries. Head injuries are generally more life threatening.

Children have a lower center of gravity than adults and their shorter height and smaller weight affects the mechanics of impact. The primary contact is higher up their body, so they tend to be hit forwards rather than rotated upwards, tend to be propelled to the ground even at lower speeds and are often run over resulting in many points of impact and various injuries. Often clothing and tissues can adhere to the undercarriage of a vehicle.

Pattern of Pedestrian injuries.

1- The points of impact on a body are important and clothing must be examined for paint chips and parts of the vehicle that may be transferred on impact.

2- Bumper impact sites on the legs should be measured from the heel. The height will correlate with the height of the bumper.

3- A bumper fracture is often triangular in shape, the apex pointing to the direction that a vehicle was moving. When the brakes are applied, a bumper fracture occurs low because the front end of the car drops.

4- When hit by a car, an adult pedestrian will be lifted up and may strike the windshield or roof or be thrown over the car. Most injuries arising from these vehicle and ground impacts to the head, legs and pelvis., tibial plateau fractures and ligamentous injuries of the knee, and traumatic brain injuries.

5- Most pedestrians are struck by motor cars or trucks- during an acceleration NOT during deceleration process.

6- Primary injuries are caused by the first impact of the vehicle on the victim, while secondary injuries are caused by subsequent contact with the ground. 'tertiary injuries' describe the impact with the ground, reserving 'secondary' for additional contact with the vehicle, as when the pedestrian is hurled up against the windscreen.

7- A further hazard is being run over by the vehicle if the victim is projected directly in front. Sometimes he may be dragged by the under-belly of the car, and seriously soiled and injured,

8- Many impacts are on the front corner of the car and the pedestrian may then be knocked diagonally out of the path of the car.

9- If thrown into the centre of the roadway, the person can be run down by a different vehicle overtaking in another lane or by one coming in the opposite direction on a single carriageway.

10- If scooped up, the victim will land on either the bonnet or against the windscreen or corner-supporting pillar (the 'A' frame).

11- The flat bonnet usually does relatively little damage, though linear abrasions, brush grazes, or friction burns may be seen. Violent contact with the windscreen, especially the rim or side pillars, is the most frequent cause of severe head injury from primary impact.

12- Scooping-up can occur at speeds as low as 23 km/hour the body will usually be projected forwards.

13- If the speed is high, the victim can be thrown up onto the car roof, sometimes somersaulting so that the head strikes the roof. He can then slide or be flung right over the back of the car, landing- behind it in the roadway. This is more likely to happen if the car does not brake.

14- In most cases, the scooped pedestrian falls or is flung off on one side of the car or the other, again to suffer secondary injuries in the road and perhaps be run over by another vehicle.

15- The scooped-up victim will acquire the speed of the car by the time he lands on the bonnet, but then the vehicle decelerates. As the adhesion to the shiny surface is small, the newly acquired velocity of the body will cause it to slide off the front of the car as the latter brakes.

16- The victim then hits the ground in front of the car, sustaining secondary injury - and may even be run over during the residual motion of the vehicle before it finally stops.

17 - In a high-speed impact, which may be anything over 50 km/ hour the body can be flung high in the air and for a considerable distance, either to the side or in the path of the car - or even backwards over the roof.

18- In general, the severity of the injuries – both primary and secondary - will be the more severe the higher the speed. It is impossible to estimate the speed of impact from the nature of the injuries.

19- These can be fatal even at slow speeds of the order of 10 km/hour, yet occasionally high-speed impacts can produce only minor damage.

20- When a pedestrian is struck by a larger vehicle, such as a van, truck or bus, the initial point of impact is higher and may cause primary damage to pelvis, abdomen, shoulder-girdle, arm or head.

21- Because of the profile of these vehicles, there is no scooping-up effect, and the victim is usually projected forwards to suffer secondary damage from road contact and sometimes to be run over.

The severity of the injuries is related to many factors Vehicle speed, The angle of impact of the vehicle upon the pedestrian, The center of gravity of the pedestrian, The part of the body that first comes into contact with the vehicle, The part of the vehicle the pedestrian impacts first & vehicle design.INJURIES TO PEDESTRIANS

1- The most common trauma is to the legs, some 85 per cent of pedestrian casualties having lower limb injuries.

2- Abrasions and lacerations to the upper shin and knee area are typical of car bumper contact, and fractures of the tibia and fibula, often compound, are so common that they are present in a quarter of fatalities, according to Eckert.

3- The femur is fractured less often. The mid-shaft may be broken or the head may be driven into the acetabulum, together with a fractured pelvis.

4- If the leg is weight-bearing at the time of the impact, the tibia1 fracture tends to be oblique, whereas if not lifting during walking, the fracture line is often transverse.

5- When both shins are damaged, the level may be different on each side; this indicates that the person was moving at the time, with one leg raised in walking or running.

6- Traffic accidents are the most frequent cause of skull fracture, especially of the base. Fractures of chest, arm and pelvis and injuries to the abdomen follow in frequency

7- Often the injuries are concentrated on one side, usually on the opposite side to the point of primary impact, because the body was thrown down onto the road.

8- Because of rotation and the variable posture from being thrown off the car structure, however, the injuries are often widespread and may show no particular pattern.

9- Soft tissue injuries are common and, apart from abrasions, bruises and lacerations, muscle laceration and crushing can occur.

10- A characteristic lesion from running-over, as opposed to knocking-down, is the 'flaying' injury, where a rotating motor wheel tears the skin and muscle from a limb or head.

11- The rotatory effect against a fixed limb may strip off almost all tissue down to the bone.

12- When a wheel passes over the abdomen or pelvis, multiple parallel striae or shallow lacerations may occur near the contact area because of ripping tension in the skin. 13- When a wheel passes over the pelvis, abdomen or head, there may be great internal damage with little surface injury.

14- The weight of a large vehicle can virtually flatten a head, crushing the cranial vault. Often the brain is extruded through scalp lacerations, as may be the intestine through an abdominal wound.

15- The pelvis may flatten out when run over, the symphysis or superior rami breaking, and one or both sacroiliac joints becoming detached.

16- Any type of intra-abdominal injury may occur from ruptured liver and spleen to perforated intestine, lacerated mesentery and fractured lumbar spine.

17- In the chest, ribs, sternum and thoracic spine may fracture, and heart and lung damage occur from crushing or laceration from jagged ribs.

18- A 'flail chest' is sometimes produced when a heavy wheel runs across the supine body, breaking all the ribs on each side in the anterior axillary line.

19- Patterned injuries may be important, in that they can assist the police in identifying a vehicle in a 'hit-and-run‘ accident. The most common is a tyre pattern outlined in intra-dermal bruising and these should be measured carefully and photographed.

20- These marks are usually caused by the skin being forced into the grooves of the tyre tread, the edge of the raised rubber tracing out the pattern. The elevated parts do not leave bruises, but may imprint dirt on the skin.

21- Paint fragments and glass shards are also trace evidence that must be carefully retained, as the forensic laboratory may be able to identify the make and model of vehicle involved, and match the fragments when a suspect car is examined.

22-Suprarenal haemorrhage is more common in the right gland than the left after a traffic injury in Britain, but this observation that many such haemorrhages occur several days after the trauma and are usually the result of general systemic effects, rather than direct impact.

INJURIES TO MOTORCYCLISTS

1- The rate of injury and death amongst motorcyclists is far higher than among car drivers.

2-The two extremities of the body suffer most in motorcycle accidents, though Larsen and Hardt-Madsen's analysis (1988) showed high injury rates for chest and abdomen. Because the rider inevitably falls to the ground, head injuries are common and often severe,

3- Though crash helmets are mandatory in most countries, the severity of the impact often defeats its protective effect. Impact with the road surface or another vehicle at speed causes skull fractures at any part of the head, but often temporoparietal.

4- A common complication is a basal skull fracture, especially a 'hinge' fracture. This transverse crack across the floor of the skull, crossing the petrous base or behind the greater wing of the sphenoid bones through the pituitary fossa to the opposite side, has also been called 'the motorcyclist's fracture'.

5- Another type is the ring fracture around the foramen magnum in the posterior fossa caused by an impact on the crown of the head.

6- There are often cervical spine fractures found in over a quarter of his series. Brain damage may be severe, even with a helmet in place. Cortical contusion and laceration, sometimes contrecoup, may be gross enough to cause brain tissue to extrude through compound fractures of the skull.

7- In Mant's series of motorcyclists, 60 % had skull fractures and almost 80 % had brain damage.

8- The legs are often injured, either by primary impact with another vehicle or fixed road structures, or by becoming trapped by part of the motorcycle frame. Lacerations, friction burns and fractures – often compound - are common.

9- Any part of the body may suffer injury, but less often than the extremities. Falling from the machine, especially at speed, can cause rib fractures and visceral damage, especially rupture of the liver and spleen.

10- An injury common with motorcycles is the 'tail-gating‘accident, where a rider drives into the back of a truck so that the machine passes underneath, but the head of the motorcyclist impacts upon the tail-board.

11- Decapitation may occur in the most extreme cases, but severe head and neck injuries are almost inevitable.

INJURIES TO PEDAL CYCLISTS

1- These form a less severe counterpart of motorcycle lesions, as the pedal cycle has the same instability but far lower speeds.

2- Head injuries figure largely in accidents, as the height above the ground is considerable and the rider suffers from the passive fall, added to by any forward motion or projection from impact by a motor vehicle.

3- Other injuries are from the primary impact from a striking vehicle, which may hit the rider around thigh, hip or chest level. 4- Secondary damage to the shoulder, chest and arm may occur from striking the ground, when friction grazes are common.

5- (A unique injury, though not fatal, was entrapment of the leg between wheel spokes with compression of the soft tissues of the calf, when the leg penetrated the wheel.)

RAILWAY INJURIES1- where a public road crosses a railway track with either no barrier at all or with only a flimsy lifting pole. Many vehicles are struck each year by passing locomotives.

2- Few rail passengers are killed or injured in moving trains compared with accidents to railway staff and to other types of accident on railway property. Track workers may be run down and some die from electrocution from overhead cables.

3- The pathology of all these is no different from accidents elsewhere, the malicious damage caused to trains, either by placing objects on the tracks, which may cause a derailment, or the dropping of objects from bridges.

4- The other fairly common railway fatality is the suicide who lays himself in front of an approaching train. Decapitation is the most common injury. and the obvious features are the local tissue destruction, usually with grease, rust or other dirt soiling of the damaged area. The usual search for alcohol and other drugs

5- Jumping from the subway platform of an underground 'tube‘ or 'metro' system. Here injuries are sometimes complicated by high-voltage electrical lesions, as the typical traction voltage of an electric railway is in excess of 600 volts.

1. Peden M. World Report on Road Traffic Injury Prevention: Summary. World Health Organization. 20042. Traffic Safety Facts 2004:Pedestrians. National Highway and Transportation Safety Administration. 20043. Mohan D. Traffic safety and health in Indian cities. Journal of Transport and Infrastructure. 2002;9:79–92.4. Koppits E, Cropper M. Traffic Fatalities and Economic Growth. The World Bank. 20035. Blincoe L, Seay A, Zaloshnja E. The Economic Impact of Motor Vehicle Crashes, 2000. National Highway Traffic Safety Administration. 20026. Holbrook TL, Hoyt DB, Coimbra R, Potenza B, Sise M, Anderson JP. Long-term posttraumatic stress disorder persists after major trauma in adolescents: New data on risk factors and functional outcomeJournal of Trauma 2005. 584764–9.9discussion 9–71. [PubMed]7. Frommberger UH, Stieglitz RD, Nyberg E, Schlickewei W, Kuner E, Berger M. Prediction of posttraumatic stress disorder by immediate reactions to trauma:A prospective study in road traffic accident victims. European Arch Psychiatry Clinical Neuroscience. 1998;248(6):316–21. [PubMed]8. Shankar U. Pedestrian Roadway Fatalities. National Highway Traffic Safety Administration. 20039. Fatality Facts 2004:Pedestrians. Insurance Institute for Highway Safety. 200410. Web-based Injury Statistics Query and Reporting System (WISQARS) Centers for Disease Control; National Center for Injury Prevention and Control. 2003.11. MacKenzie EJ, Morris JA, Jr, Smith GS, Fahey M. Acute hospital costs of trauma in the United States: Implications for regionalized systems of care Journal of Trauma 1990. 3091096–101.101discussion 101–3. [PubMed]

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