home Zoology Mechanisms of traumatic impact of blunt objects. Classification of blunt objects. The mechanism of action of blunt objects, causing damage. Long tubular bones

Mechanisms of traumatic impact of blunt objects. Classification of blunt objects. The mechanism of action of blunt objects, causing damage. Long tubular bones

blunt objects- objects that do not have a sharp piercing end and a sharp cutting edge, that is, a blade.

Classification of blunt objects:

1. Parts of the human body - arm, leg, head

2. Objects used for striking or throwing - stones, sticks

3. Massive blunt objects, the damage of which is accompanied by the appearance of signs of a general concussion of the body - vehicles, falls from a height

Blunt objects are also distinguished:

a) with a limited surface - the boundaries of the traumatic surface (all or some of them) do not go beyond the surface of the damaged part of the body and with an unlimited surface - the dimensions of the traumatic surface of a blunt object go beyond the impact area

b) with a smooth (smooth) and with a non-smooth (rough) surface

c) according to the shape of the traumatic surface:

1) flat (triangular, square, rectangular, polygonal, oval, round)

2) angular (in the form of a dihedral angle - ribbed, in the form of a trihedral angle - vertices, etc.)

3) curve (spherical, cylindrical, etc.)

4) combined (flat and curve, flat and angular, etc.)

The mechanism of action of blunt objects:

1) blow with a blunt object - a complex short-term process of interaction between the body (or body part) of a person and a blunt object, in which the latter has an impulsive unilateral centripetal effect on the body or body part. The impact action can last less than 0.1-0.01 s. The shorter the impact time, the more energy is transferred to the affected body part and the greater the amount of damage. However, with an ultrashort impact time, a paradoxical effect occurs: the amount of damage becomes smaller, since only an insignificant part of the energy of the damaging object is transferred to the damaged part of the body. The last option in forensic practice occurs in exceptional cases. Impact action is exerted by both a moving object (for example, a thrown stone, protruding parts of a moving car, etc.) and a stationary one (for example, a headbutt when falling to the ground); massive objects, acting with great force, can lead to a concussion of the body or part of the human body.

2) compression is the process of interaction of the body or part of the body of a person with two, as a rule, massive, hard, blunt objects, in which both of these objects, acting towards each other, have a bilateral centripetal effect on the body or part of the body. The compression time is calculated in seconds, and in some cases - minutes. Of the two squeezing objects, one is always mobile, the other is most often motionless, for example, pressing a person with a car body to stationary objects (house wall, fence, etc.)

3) stretching is the process of interaction of the body or part of the body of a person with two solid objects, which, acting in divergent directions, have a bilateral centrifugal effect on the body or part of the body. Stretching time - tenths of a second, less often - a few seconds. Of two objects, one is always mobile, the other is usually motionless. An immovable object fixes the body or part of the body (for example, the body of the machine), and another object has an eccentric action (rotating parts of the machine).

4) flexion or extension

5) twisting

6) friction - the process of surface interaction of the damaged surface of the body and the damaging surface of a blunt solid object, in which both contact surfaces are displaced in a tangential or tangential direction relative to one another. Both the damaged part of the body and the damaging object, or both, can be mobile.

Result of blunt force injuries: 1) bruises 2) abrasions 3) wounds 4) fractures 5) dislocations 6) fractures 7) separation of body parts (transport amputations: complete, partial)

6. Abrasion: definition of the concept, mechanism of formation, forensic significance.

Abrasion- this is a superficial violation of the integrity of the skin (up to the reticular layer of the dermis), less often the mucous membranes.

Scratch- linear abrasion.

Mechanism of Education: blow with a blunt object at an acute angle to the surface of the body (from 30 to 70 °).

1) the nature of the traumatic object - particles of a damaging object (pieces of wood, sand, inclusions of coal dust particles) are sometimes found on the surface of the abrasion

2) concretization of the features of the traumatic object

a) static action - crescentic abrasions from nails

b) dynamic action - strip shape

3) the place of application of the traumatic force - an abrasion is always located at the place of application of the traumatic force.

4) vitality - the diagnostic sign is the presence of reactive processes on the border between sedimentation and intact skin.

5) prescription - carried out according to the study of the crust:

a) the first 10-12 hours - the bottom of the abrasion is below the level of the surrounding tissues

b) the end of the 1st day - the bottom of the abrasion at the level of the surrounding tissues

c) 2-3rd day - the crust is above the level of the skin

d) 3-5 days - detachment of the crust along the periphery

e) 5-7th day - the crust disappears, at the site of the abrasion, a depigmentation area is formed that is lighter than normal skin.

f) 1.5-2 weeks - normalization of skin color

6) the direction of damage - a study by microscopy shows that at the beginning of the abrasion, the epidermis is evenly or tortuously torn off, and at the end it is turned towards the motionless skin or rises above it.

7) assumption of the purpose of violence

8) assumption of the number of traumatic effects

9) determination of the severity of bodily injury

7. Bruising: definition of the concept, mechanism of formation, forensic significance.

Bruise- accumulation of blood in soft tissues, mainly in the superficial layers (skin, subcutaneous tissue). They are formed as a result of rupture of the blood vessels of the skin and soft tissues with various types of mechanical action without breaking the skin. The spilled blood impregnates the damaged soft tissues. The deeper the hemorrhage is localized, the longer the color of the bruise does not appear.

Mechanism of Education: blow with a blunt object at a right or approximately right angle to the surface of the body.

1) the nature of the traumatic object

2) concretization of the features of traumatic blunt objects - the shape of the bruise in some cases may turn out to be a negative reflection of the striking (contact) part of the object (when hit by a cylinder, there will be a strip-like enlightenment in the center).

3) prescription of damage - by color change:

a) 2-3 hours - purple-red color

b) 1.5-2 days - gradually turn blue towards the center along the periphery

c) 3-4 days - green

d) 5-6 days - yellow

e) after 2 weeks - gradually turns pale and disappears

4) intravital or posthumous occurrence.

Macro-signs of intravital bruising:

Signs of inflammation (edema and hyperemia)

- "thin" bruising - a section of subcutaneous fat or skin is evenly saturated with blood on the incision

- "thick" bruising - when excess blood coagulates and forms a cavity

Micro-signs of intravital bruising:

Signs of inflammation (arterial hyperemia and edema, leukocyte infiltration)

Extensive hemorrhage (occupies at least 1.5-2 fields of view under a low magnification microscope)

From the bulk of the outflowing blood, we see the separation of several red blood cells that have spread further than the hemorrhage (into the sweat glands and surrounding tissues)

5) the place of application of the traumatic force - as a rule, a bruise occurs at the place of application of the force, but it can also be in the underlying sections (when you hit the back of the nose, swelling of the eyelids occurs, especially the lower one; when you hit the back of the thigh, the bruise is found in the popliteal fossa)

6) assumption of the purpose of violence (bruising on inner surface hips during rape)

7) assumption of the number of traumatic effects

8) determination of the severity of bodily injury

8. Wound: definition of the concept, mechanisms of formation, forensic significance.

Wound- violation of the integrity of the skin, subcutaneous fat and deeper tissues (muscles, etc.)

Education mechanism: hit with a blunt object.

Types of wounds with blunt objects:

1) bruised

3) crushed

4) bitten

5) patchwork

6) scalped

Characteristics of a bruised wound:

1. shape - atypical shape (slit-like, star-shaped, linear, arcuate)

2. Edges - uneven, wavy, raw, bruised, comparable, no tissue defect

3. ends (corners of the wound) - rounded

4. the wound is shallow, i.e. length and width more depth

5. detection of tissue bridges in the depth of wounds (in the area of corners, since a large energy acts in the center)

6. external bleeding

SME: wounds caused by blunt objects indicate:

1. variant of traumatic impact (impact, compression, stretching, friction);

2. prescription of the injury:

a. within the 1st hour: an increase in the activity of aminopeptidase (detected histochemically); stases, thrombi, secondary foci of necrosis are formed in parallel

b. after 4 hours - a perivascular accumulation of segmented leukocytes appears

in. after 6 hours - macrophages and single mast cells can be found in the area of inflammation

after 12-15 hours - mitoses appear in the tissues

by the end of the day - the first signs of regeneration of the epithelium along the edges of the wound

e. on the 3rd day - neoplasms of budding capillaries, the appearance of granulation tissue

and. after 1 week - the structure of the healing wound is made up of collagen fibers

h. after 1-1.5 months, the scars take their permanent shape, elastic fibers appear in them, the capillaries almost completely disappear. Microscopically, the scar: thinning of the epidermis, absence of normal skin papillae, sebaceous and sweat glands, coarsening (hyalinosis after 3-6 months).

Infected wounds take longer to heal.

3. blunt nature of the impact;

4. number of traumatic impacts;

5. the shape, dimensions of the traumatic surface and the material of the blunt object, the nature of foreign layers on its surface - blunt objects acting as a spherical or cylindrical surface cause rectilinear wounds with additional edge breaks. They are surrounded by a relatively wide sedimentation. The edges of such wounds are often crushed.

6. place, direction and strength of the traumatic effect - the walls of wounds arising from a perpendicular impact are sheer; when struck at an angle, one of the walls of the wound is beveled, the other is undermined.

9. Fractures: definition of the concept, mechanisms of formation. Morphological signs of direct and indirect fractures of the ribs.

bone fractures- violation of their anatomical integrity, accompanied by damage to the surrounding soft tissues to a greater or lesser extent. There are fractures:

a) straight- arise from direct contact traumatic action. In the place of contact of the traumatic object with the bone, destruction, crushing and mutual layering of bone structures occur. As a result, small defects are observed at the place of application of the force due to the chipping of the bone substance. Elevated flat bone plates are visible along the edges of the defect, often overlapping each other and giving the impression of a tiled roof. The edges of direct fractures are coarsely serrated broken lines.

b) indirect (fractures throughout)- arise from indirect action. The edges of indirect fractures are a finely serrated line.

Mechanisms of Education fractures of tubular bones:

a) bone shear- occurs from a sharp blow with an edge, edge or narrow limited surface of a blunt object. Shear fractures are always straight. They have the character of transverse or oblique transverse. A small cleavage of a compact substance is formed at the place where the force is applied. Thin cracks extend from the edges of the fracture, the free ends of which indicate the place of impact. Sometimes the ends of the cracks extending from the opposite edges of the fracture unite and form a large fragment at the site of impact, most often diamond-shaped.

b) bone fold- leads to a change in mechanical stresses in the bones: a zone of tension appears on the convex surface of the bend, and compression occurs on the curved surface. Since the bone is less resistant to stretching, a transverse crack forms on the convex surface of the diaphysis, which extends to side surfaces where it splits. The ends of the crack are connected on the compression side, forming a large fragment. Flexion of the tubular bone can occur with transverse pressure on the diaphysis (for example, when moving with a car wheel), with longitudinal pressure on the bone, and also with flexion of the bone, one of the epiphyses of which is fixed.

in) bone compression in the longitudinal direction - underlies the formation of impacted fractures. They are localized in the metadiaphyseal region and represent a local compression destruction of the beam structure, which is often combined with fractures that split the diaphysis in the longitudinal direction. Such fractures occur when falling from a great height onto straightened legs.

G) bone twisting- represents its rotation around the longitudinal axis while simultaneously fixing one of its (bone) ends. In this case, helical fractures occur (often observed in skiers).

The separation of the bone substance is possible only in the area of attachment of the tendons. The detached part of the bone mass is usually small. As a rule, such fractures are observed with sharp tendon tension in young subjects with incomplete ossification processes.

Fractures of flat bones depend on the size and shape of the traumatic surface of a blunt solid object and the variant of its action: impact or compression.

a) From the blow unilateral direct fractures occur at the site of application of force. Objects with a limited impact surface acting with little force can cause a linear fracture (crack) that expands in the direction of impact. Several radially diverging fractures may also form at the site of application of the force. Additional cracks may radiate from some of them, which, connecting and mutually intersecting, can form comminuted fractures in a limited area of the cranial vault. With stronger impacts, depressed fractures are formed, corresponding to the size of the traumatic surface and often being a negative reflection of its shape. Along the edges of such fractures, fragments arranged in steps can form, which gives reason to call these fractures terrace-shaped. High-strength blows can cause a complete shift of the bone area with the formation of a perforated fracture, which reflects the shape and size of the traumatic surface of the object. A small impact, caused by an unbounded surface of a blunt hard object, can lead to the formation of one or two or three radially divergent cracks. When hitting a large force in the place of its application, a focus of comminuted fractures is formed, limited by an arcuate crack. Linear cracks radiate from this source. The stronger the blow, the greater the area of the focus of comminuted fractures. In the zone of the focus of comminuted fractures, deformation in the form of a flattening of the skull is noticeable.

b) When squeezed forces are applied to mutually opposite surfaces of the head and are directed towards each other. In places where force is applied, foci of finely comminuted fractures are formed, surrounded by one or more concentric arcuate cracks following one after another. The foci of comminuted fractures are united by rectilinear or somewhat curved cracks, showing the direction of compression. Compression is often accompanied by deformation of the head, up to its complete flattening. AT rare cases under compression, a single linear crack is formed. It arises from stretching (cracking) of the bone outside the place of application of force and is an indirect fracture.

With several blows to the head, the line of fracture formed from the subsequent blow will be interrupted by the lines of fractures that have arisen from previous blows.

When hitting the chest at the site of impacts, straight, transverse or comminuted fractures of the ribs or sternum occur, accompanied by ruptures of the parietal pleura. When compressed, multiple bilateral double and triple fractures of the ribs are formed: direct fractures occur at the places where the force is applied, and indirect fractures at a distance from the place where the force is applied.

Spinal fractures from a local impact lead to comminuted fractures of the bodies and processes of individual vertebrae. Under the action of forces along the axis of the spine, compression fractures of the vertebral bodies are formed. With excessively sharp flexion of the spine, dislocations and wedge-shaped compression of the anterior sections of the bodies of the cervical vertebrae most often occur (with extension, the posterior sections). Such fractures are usually accompanied by damage to the ligamentous apparatus of the spine. These fractures are not uncommon in traffic accidents, and the mechanism of their occurrence is called whiplash injuries.

When struck in the pelvic area in the place of application of force, unilateral direct single, or double transverse, or comminuted fractures occur. When the pelvis is compressed, bilateral double vertical fractures are formed: direct fractures of the pelvic bones are found in the places where the force is applied, and at a distance, indirect fractures of the pelvic bones. Microstructural changes in the fracture zone also make it possible to differentiate the mechanism of violation of the integrity of the bone tissue.

SME - fractures allow you to establish:

1. blunt nature of the impact;

2. fact, type, place, direction, strength and variant of traumatic impact;

3. prescription of injury;

4. number and sequence of blows;

5. the shape and size of the traumatic surface of a blunt object.

Direct fracture of the rib (extensor) - a fracture of the rib that occurs at the site of application of the traumatic force.

Indirect fracture of the rib (flexion, structural) - a fracture of the rib that occurs at a distance from the place of application of the traumatic force.

Morphological signs of direct and indirect fractures.

With a direct fracture, the fragments are directed inward chest, the fracture line is oblique, signs of compression are on the outer bone plate, and stretching is on the inner. With an indirect fracture, the fragments are directed outward of the chest, the fracture line is transverse, signs of compression are on the inside of the bone plate, and stretching is on the outside.

Signs of compression:

The fracture line is coarsely serrated, the teeth are sharp

Chipping of the bone substance (loss of bone substance)

Chipped bone

The edges are completely incomparable

Signs of stretching:

The edges are relatively even, may be finely serrated, the tops of the teeth are rounded

No chips or cracks

Edges are fully comparable

Most mechanical damage is caused by blunt objects, which are most common in everyday life and technology. The word "blunt" characterizes, first of all, the surface of the object, which at the time of the occurrence of damage is in contact with the body. Blunt objects can be hard, elastic and soft (pillow, rope, etc.). Mechanical damage is usually caused by blunt solid objects.

The blunt objects themselves are diverse in their mass, density, and features of the traumatic surface. The conditions under which these objects cause damage are also different: the kinetic energy at the moment contact ( collisions) of a blunt object with the human body; place of contact (localization of damage); the angle at which a blunt solid object acts. The features of the damaged part of the body are also not the same. All this causes a wide variety of morphology and functional manifestations of injuries from blunt hard objects. At the same time, all injuries from blunt solid objects have similar, typical group signs and features that allow them to be differentiated from other mechanical injuries.

Important in the nature of damage from blunt solid objects are the features of their surface.

An idea of the nature of the damaging surface of blunt solid objects is given by the classification developed by A.I. Mukhanov (1969).

He distinguishes between blunt solid objects:

- With a flat predominant surface (board, plate, etc.);

With a flat limited surface: rectangular, triangular, round (hammer, stone, etc.);

With a spherical surface (dumbbells, weights, etc.);

With a cylindrical surface (stick, pipe, etc.);

With a surface ending in a trihedral angle;

With a surface ending in a dihedral angle or edge (cleaver, edge of a curbstone, edge of a board, edge of a table).

It should be borne in mind that the damaging surface of the object can be smooth, rough or embossed, with flat elevations or depressions. This is taken into account in the classification of L.A. Solokhina and A.I. Kuznetsov, who offer to distinguish between smooth or embossed surfaces with different patterns.

The following types of interaction between a blunt solid object and the body are distinguished, since during traumatization it does not matter whether the human body or part of it is at rest, and the damaging object moves or vice versa.

Hit- this is a sharp dynamic impact of a traumatic object and body, in which the action of traumatic forces is centripetal, and the contact (or impact) time is not more than 50 ms.

Shake- this is a dynamic centrifugal load, lasting 50–200 ms, which manifests itself under general effects on the human body by inertial displacement of tissues and organs, which is accompanied by tension, overextension, ruptures of the fixing and ligamentous apparatus with the formation of hemorrhages.

compression- this is a static action of two or more traumatic objects on the body with a centripetal action of forces lasting more than 200 ms.

Friction (sliding)- this is a dynamic load of a centrifugal nature, due to the tangential (tangential) impact of a traumatic force with a contact time of 1-200 ms.

Stretch (stretch)- a process opposite to compression, resulting from the impact on the body of two or more blunt solid objects in divergent directions. These mechanisms of action of blunt solid objects rarely occur in isolation. As a rule, there is a combination of two or more mechanisms acting simultaneously or in very rapid succession, which causes a variety of emerging damage and their features.

Bruising and abrasions occur mainly when exposed to blunt hard objects. Bruising is usually caused by transverse impact or pressure, and abrasions are usually due to impact, pressure, strain, friction, or a combination of these.

Wounds occur as a result of impact, compression, stretching and friction, as well as a combination of these effects.

Wounds formed from the action of a blunt solid object are characterized by the following properties: - no skin defect; - finely or coarsely serrated, and sometimes crushed, sheer or beveled edges; - rounded or blunt ends; - bruising, and more often of varying severity, sedimentation of the skin in the circumference; - the presence of connective tissue bridges and protruding (dislocated) intact hair follicles into the lumen; - Penetration to the underlying tissues or to the bone. Such wounds are called bruised.

In some cases, when located directly above the bone formations (for example, on the scalp), the combination of the above listed properties of bruised wounds makes it possible to clarify the nature of the acting surface of a blunt solid object. So, star-shaped wounds with large-toothed edges and crushing in the center, located against the background of wide sedimentation of the surrounding skin, occur when exposed to a wide surface of the object. Wounds of a linear shape with finely serrated edges, rounded ends and without pronounced sedimentation in the circumference are formed when the edge of the object is exposed. Star-shaped wounds with three rays converging at one point, finely serrated edges, rounded ends and without pronounced precipitation in the circumference are characteristic of the action of the angle of the object. Wounds linear form with coarsely serrated edges, blunt ends, and the presence of different widths of stripe-shaped sedimentation in a circle occur when exposed to the side surface of a blunt cylindrical solid object. Wounds of an arched shape with finely serrated edges, rounded ends and the presence of more often on one (convex or concave) side of the sedimentation arise from the impact of the end part of a blunt solid cylindrical object.

Of the other injuries when exposed to hard blunt objects, there are hemorrhages, hematomas, ruptures and crushing (crushing) of soft tissues, joint damage, bone fractures, damage to internal organs, and more often their various combinations.

With all the variety and totality of damage can be encountered under certain circumstances of their infliction. When talking about this, they usually mean fall from a height, car and rail injury.

1. Examination of damage by blunt solid objects

2. Features of damage caused during attack, fight and defense

3. Injuries from automobile and railway injuries

4. Trauma from a fall.

1. EXAMINATION OF DAMAGES BY DULL AND SOLID OBJECTS

Injuries with blunt objects are more common than others due to the wide distribution of objects that, when attacking or defending, can exhibit blunt traumatic properties. Blunt action is said to be in cases where mechanical damage is caused by a surface, edge, corner or top of an object. Direct violation of the anatomical structure of tissues occurs, as a rule, when exposed to blunt solid objects. A blunt effect can be exerted by a jet of liquid or gas under high pressure. However, such observations are classified as casuistic.

Classification of blunt instruments of trauma

According to the material of manufacture, blunt instruments of injury are divided into metal, non-metal (wood, natural and artificial fibers (ropes), leather (belts), rubber, synthetic and other materials).

According to the degree of rigidity, blunt tools are soft, elastic, semi-rigid, and hard.

The sizes distinguish limited and unlimited (wide) traumatic surfaces. A limited surface is such a surface, the boundaries of which (all or some of them) do not go beyond the surface of the damaged part of the body. If the dimensions of the traumatic surface of a blunt object go beyond the impact area, then such a surface is considered as unlimited. When hit by an object with a limited traumatic surface, the shape and size of the damage are determined primarily by the size and shape of the traumatic surface. When exposed to an object with an unlimited surface, the shape and size of the damage are mainly determined by the properties of the damaged part of the body. In case of damage from the action of an object with a limited striking surface, the size and shape of the traumatic surface of this object can be established.

The shape of the contact surface can be flat (triangular, square, rectangular, oval, round, etc.), angular (in the form of a dihedral angle - ribbed or in the form of a polyhedral angle or vertex), curve (spherical, cylindrical, etc.) and combined ( a combination of flat and curved, flat and angular surfaces, other combinations).

The relief of the striking surface may be smooth or rough.

By changes in integrity and shape due to impact, blunt tools can be indestructible and not changing shape (for example, a granite stone; collapsing and changing shape (for example, a wooden board; indestructible but changing shape; crumbling (for example, brick); crushing (for example, a glass bottle) .

According to the mechanism of action, they are distinguished five main mechanisms of blunt trauma: impact, compression, stretching, friction and concussion

Impact - a short-term sharp and strong push arising from an impulsive one-sided centripetal impact on the body of a blunt solid object. The impact may last less than a tenth of a second. The shorter the impact time, the more energy is transferred to the affected body part, the greater the amount of damage. Massive objects acting with great force are capable of shaking the body or part of the human body.

Depending on the place of application of force, they distinguish central and non-central blows. In this case, whether or not the centers of mass of moving bodies are on the same line are taken into account.

Depending on the direction of impact, there are straight and oblique blows.

Depending on the angle of impact, centripetal and centrifugal impacts are distinguished. Centripetal called a right angle strike. An impact at an acute angle, along an arc or a tangent is called centrifugal.

Compression is a long-term bilateral centripetal effect on the body of two blunt objects. The compression time is calculated in seconds, sometimes minutes. Of the two squeezing objects, one is always mobile, the other is most often motionless.

Compression can occur offset or no offset.

Displacement is not observed in the case of impact at a right angle. In this case, the tissue is flattened, compressed from opposite sides, stretched in the center and along the edges, and then crushed at the point of contact with the tool. This compression is characterized by locality, limitedness and massiveness of damage at the place of application of force.

Offset compression is observed when the tool moves at an acute angle. In places where force is applied, the tissue is flattened, compressed, stretched on the opposite side, sometimes torn, forming a slit-like wound or patchwork wound. For compression with displacement of compressing tools, the prevalence, vastness and massiveness of injuries, stratification of tissues, their transformation and organs into a shapeless homogeneous mass, and the movement of organs are characteristic.

Tension is the elongation of tissue due to the strong tension caused by the centrifugal action in the diverging direction of two solid objects. Stretching lasts from tenths of a second to several seconds. Of two objects, one is always mobile, the other is usually motionless. An immovable object fixes the body or part of it, while the other has an eccentric effect.

Friction is the process of surface interaction of the damaged surface of the body and the damaging surface of a blunt solid object, in which both contact surfaces are displaced in a tangential or tangential direction relative to one another. Both the damaged part of the body and the damaging object, or both, can be mobile.

Concussion - wave-like vibrations of tissues that arose after the impact and at a distance from it, which is accompanied by tissue stretching, subcapsular hemorrhages and cracks, torn ligaments, ruptures of organs.

From the action of blunt objects, damage to soft tissues, bones and internal organs is formed (Table 4.1). The morphological features of these injuries make it possible to determine: signs (properties) of a traumatic blunt object; damage generation mechanism.

The essence (type) of damage is determined by the variant of traumatic blunt impact. Bruised wounds, fractures will be typical for impact action; for compression - flattening of a part of the body, kneading organs and tissues; for stretching - lacerations, skin detachment; for friction - extensive precipitation. At the same time, some types of damage may be the result of different mechanisms. So, bruising occurs both from a blow and from compression; abrasions - both from impact and friction; ruptures of internal organs - from impact, compression and stretching.

With all the variety of traumatic factors and circumstances of injury in blunt trauma, the mechanisms of injury are limited to four: impact, compression, stretching and friction.

In general, the mechanism of damage formation is understood as the process contact interaction traumatic surface and damaged part of the body, leading to the occurrence of anatomical and functional damage of a certain type and nature.

Hit, those. a sharp strong push, when in a relatively short period of time there is a collision of an object and a human body relative to each other. In the place of their contact, various injuries occur, the nature of which depends on the force of the blow, its direction, the shape and size of the striking surface, the presence and characteristics of clothing or other pads, the anatomical structure of the damaged part of the body, and some other factors.

Typical impact injuries will be abrasions, bruises, contusions, direct bone fractures, ruptures of organs at the point of application of force.

bruised wounds arise from blows with blunt objects on parts of the body with a thin layer of soft tissues, under which the bones are located. Their shape depends on the shape and size of the striking object. In typical cases, the edges of the wounds are uneven, raw, bruised, crushed, sometimes exfoliated from the underlying tissues. In the depths of the wounds, jumpers of more durable tissues are visible. The hair follicles along the edges of the wound retain their structure.

fractures when struck with a blunt object, they are characterized by uneven jagged edges of damaged bones.

When struck with a sufficiently large force by an object with a wide striking surface, in addition to damage at the site of direct impact, there is also shake the whole body or parts of it, mainly internal organs. Concussion in mild degree may not cause noticeable anatomical changes, but be limited to functional disorders. In this connection special meaning gets a concussion. If it is accompanied by local changes in the form of hemorrhages and areas of crushing of the medulla at the site of impact and counter-impact, then such changes are diagnosed as brain contusion.

At severe concussions internal organs, characteristic lesions are formed: multiple hemorrhages in the fixing apparatus of the organ and the surrounding tissue under the capsule and in the parenchyma of the organ. If the force of impact and shaking of the body is large, then, as a rule, there are multiple, located parallel to each other, lacerations of internal organs.

compression, unlike impact, it occurs when two centripetal forces act on the body from opposite sides. The speed of movement of squeezing objects, as a rule, is low, and the time of their interaction with the human body is much longer than with an impact. The severity and volume of damage is determined by the mass of the object and the area of its contact with the damaged part of the body.

The most typical injuries during compression are: crushing, dismemberment, separation and displacement of organs, bilateral multiple direct and indirect bone fractures.

stretching, in essence, is a mechanism directly opposite to compression, i.e. forces act centrifugally and lead to characteristic injuries: separation of body parts, ruptures of ligaments, intervertebral discs, superficial linear tears of the skin from overstretching, bruised and lacerated wounds.

lacerations arise from stretching the skin with bone fragments and when struck with blunt objects at an acute angle. They are localized mainly in the area of bone fractures or along the edges of detachments of body parts. When these wounds are localized in the area of impact with a blunt object along the tangent initial part they often show signs of injury. In such cases, wounds are more correctly called bruised and torn(This group also includes bitten wounds).

The shape of the wounds is linear or L-shaped with uneven patchwork edges, in which there is no settling, crushing and bruising, which distinguishes these wounds from bruised ones.

Friction as a mechanism for the formation of injuries, it consists either in the contact of the traumatic object with the human body and movement in relation to it tangentially, or in the sliding of the body on some object. In this case, as a rule, superficial damage is formed: abrasions, wounds, detachments of the skin from the underlying tissues in the form of "pockets". In some cases, during prolonged dragging of the body (traffic injury), deeper damage appears in the form of “erasing” or “sawing” of the bones.

Often, individual mechanisms of damage occur in combination with each other, which creates certain difficulties in the production of examinations.

Let us consider some morphological features of injuries caused by blunt objects. First of all, the dimensions of the acting surface in relation to the damaged part of the body or, more precisely, the contact zone of the object and the human body, the shape of the surface and the mass of the object matter. The nature of damage is influenced by the presence of faces, edges and corners of blunt objects. The same object can inflict damage of different characteristics depending on which part of the object was hit.

Blunt objects with a large flat surface lead to abrasions, bruising, and, rarely, wounds. So, when hitting the head, wounds of a rectilinear, arcuate, zigzag and star-shaped form are formed, surrounded by extensive areas of sedimentation of an irregular round shape. The edges of these wounds are uneven, bruising and often crushed, and when struck at an angle, their detachment is possible.

In addition, blows to the head form vault cracks and grounds skulls, coinciding mainly with the direction of the traumatic force, as well as comminuted fractures with characteristic small fragments in the impact area and radially divergent fractures from bone cracking. Sometimes a large bone fragment surrounded by small ones is revealed at the site of impact.

A blunt object with a large spherical surface, when exposed, leaves wounds mainly star shape with settling around and crushing of the edges. Cracks form in the bones of the skull, depressed fractures rounded and comminuted fractures.

Elongated objects with a cylindrical surface form upon impact band-like bruising with precipitation. Sufficiently thick objects can be left on the body upon impact two parallel band-like bruises, i.e. bruises are more easily formed when the skin is stretched at the border of the cylindrical surface than when its vessels are squeezed by the convex part of the object.

Rectilinear and arcuate wounds with uneven crushed edges and sedimentation appear on the scalp, and depressed fractures of an elongated oval shape with cracks and free fragments in the center are formed in the bones of the skull.

The edge of a faceted object, on impact, causes a bruised wound, which may resemble a chopped and even cut one. Shape them linear, and when gaping - fusiform. The edges are relatively even without crushing and with weakly pronounced sedimentation. Detachment of the skin is possible when the object is applied at an angle. In the bones of the skull, the edge of a faceted object forms depressed and depressed-perforated fractures.

Obtuse objects with a small surface form wounds, the shape of which depends on which part of the object and at what angle the damage is applied. In this case, the wounds only partially reflect the shape of the facet due to the predominant action of the edge of the object from any one side. Depressed and perforated fractures occur in the bones of the skull, the shape and size of which are determined by the striking face of the object.

The corners (protrusions) of a blunt object upon impact form star-shaped wounds with three rays of tears from the edges of the corner and by upsetting the edges with faces. Depressed fractures are formed in the bones of the skull, sometimes having a distinct shape of a trihedral pyramid, the top of which turned into the cranial cavity.

In addition, damage, similar in nature and mechanism to damage with blunt objects, can be inflicted by an unarmed person with parts of his body or animals.

Among the injuries inflicted by an unarmed person, in the first place are injuries by hands: fingers, nails, fist, palm. Next in frequency are injuries to the legs (foot) and teeth. Much less common are injuries from blows to the head, knee, shin and elbow.

Hand damage. Compression by the fingers of any part of the body leads to the formation of round or oval bruises: on the side of the thumb - one, on the side of the rest - several bruises, sometimes merging with each other. In the area of bruising, crescentic abrasions from the nails may be visible. Pinch fingers leave behind paired bruises. Soft tissue ruptures are possible with fingers inserted into natural openings. Sliding movements with the nails form one or more parallel oblong abrasions.

Punching lead to the formation of bruises, sometimes - abrasions. Bruised wounds can occur in the area of bony protrusions located directly under the skin. With blows to the mouth area, abrasions and bruised wounds from the teeth are formed on the mucous membrane of the lips. Strong punches can cause damage to bones (nasal, zygomatic, lower jaw, ribs, sternum), teeth, ruptures of internal organs and fractures of the cartilage of the larynx. Blows to the head sometimes result in a concussion.

In forensic practice, cases of death are known after punches in the reflexogenic areas of the body.

Flat palm strikes, as a rule, do not leave any objective signs. Much more dangerous are blows with the edge of the palm, especially in the neck area, which can lead to vertebral fractures and spinal cord injury.

Leg injuries are applied on the legs, in the lower abdomen and genital area when the victim is standing or sitting. The shape of the resulting extensive bruising, sometimes merging with each other, may reflect the shape of the part of the shoe that was struck.

Multiple fractures of bones (ribs, sternum), ruptures of internal organs and closed craniocerebral injury, causing significant health problems, up to death, can occur when a person is kicked and trampled.

Tooth damage (when bitten) can be found in both the perpetrators and the victim. The resulting abrasions, bruises or wounds are located in two arcuate lines facing each other with concave sides, and repeat the shape of the teeth. The result of strong compression by the jaws of small protruding parts of the body (finger, nose, auricle) can be biting them off completely.

Human damage can be large animals (teeth, hooves and horns).

Hoof strikes horse or bull can cause fractures of the ribs, sternum, ruptures of internal organs and severe traumatic brain injury, and blows with horns- extensive lacerated, bruised-lacerated and stab wounds with penetration into the body cavities. Biting teeth cause the formation of arcuate bruised-lacerated wounds, sometimes with tearing out significant fragments of the skin and small tissues.

Bites with teeth of animals such as dog, wolf, fox, cat characterized by the formation of lacerations with ruptures of muscles and, sometimes, internal organs (esophagus, trachea, etc.). The sharp claws of these animals inflict multiple lacerated skin wounds.

Falling from height. One of the types of blunt trauma, characterized by a special mechanism of damage, is a fall from a height. In this case, the human body moves (falls), and the damaging object (the surface on which the body falls) is motionless.

In practice, there are two types of fall: from a height and on a plane.

A fall from a height is most often the result of an accident, less often a suicide or murder. People fall from windows and roofs of buildings, rocks, trees, scaffolding, stairs, shafts, wells, etc. As you can see, circumstances can be very diverse. And yet, it is possible to find common, characteristic, signs for the whole variety of fall options to establish the mechanism of injury.

So, the type of fall, the height of the fall, the mass of the human body, the features of the traumatic surface and the position of the body at the time of impact on the surface affect the nature of damage during a fall from a height.

The fall could be direct when a body falls directly onto a surface and remains on it, or indirect(stepped) with additional impacts on objects located at different heights. In addition, allocate falls free(independent) and not free(together with any object, including in a vehicle).

The most characteristic damage occurs in a direct free fall.

There are two phases of injury: primary impact and secondary. In this case, the mechanism of damage can be divided into 3 groups: direct, indirect primary and secondary.

Primary direct damage occurs at the site of the primary interaction of the body and the surface of the object.
Primary indirect damage occurs at the time of the primary impact, but at a distance from the impact site.
Secondary damage are formed in other parts of the body from secondary impact.

The localization of damage depends on the landing options, and one of common features falling from a height is the predominance of internal injuries over external ones. Outside, there are usually unilateral abrasions, bruises or bruised wounds at the points of contact between the body and the traumatic surface. Complicating the issue of the fall mechanism may be additional damage in a non-free or indirect fall. Inside - a variety of damage of various localization.

And yet, it is possible to distinguish the most typical internal injuries in various types of falls from a height.

Fall to your feet leads to the occurrence, most often symmetrical, direct fractures of the calcaneal bones; indirect fractures of the ankles and the bones of the lower leg, femoral necks and acetabulum of the pelvis; fractures of the ribs at the places of their attachment to the spine, compression fractures of the vertebrae, secondary fractures of the sternum from a blow with the chin; primary indirect ring-shaped fractures of the base of the skull. With inertial movement forward and a blow with the hands, paired fractures of the bones of the forearm occur.

When you fall to your knees primary direct fractures of the diaphysis of the bones of the lower leg and damage to other bones of the skeleton are formed, similar to cases of falling on the legs, except for the distal parts of the lower leg and feet.

Fall on the buttocks leads to the formation of primary fractures of the pelvic bones, compression fractures of the vertebrae and, less often, ring-shaped fractures of the base of the skull.

When falling on the head there are comminuted fractures of the bones of the skull, sometimes - driving the spine into the cranial cavity, compression and comminuted fractures of the spine, sternum and ribs.

With all variants of falling from a height, damage to internal organs often occurs as a result of their sudden movement and concussion. The most characteristic are the following injuries: ligaments, capsules and tissues of the liver, spleen, kidneys; tears, ruptures and hemorrhages of the pleura and roots of the lungs, aorta, large vessels of the base of the heart, mesentery of the intestine, peritoneum. When falling on the head, in addition, there is a severe craniocerebral injury with massive hemorrhages in the soft tissues of the head, bruised wounds, head deformity, and gross brain damage.

For falls on the body (i.e. flat) is characterized by a smaller amount of damage, tk. a large inertial stability of the human body is manifested in the anterior-posterior or lateral directions, in relation to the vertical. In addition, the impact force is distributed in these cases over a larger area. Such injuries may resemble a transport injury or injury from compression of the body with blunt objects, characterized by a predominance of massive hemorrhages in soft tissues, gross injuries to the organs of the chest and abdominal cavity, multiple bone fractures, mainly on the side of impact.

In a forensic medical assessment of the nature and localization of injuries in a fall from a height, the elasticity and shock-absorbing properties of the tissues of the part of the body on which the fall occurs, the resistance of the surface of the traumatic object to impact are taken into account. In addition, a thick layer of clothing can play a certain protective role in reducing the amount of damage.

Fall to the plane. The second type of fall is fall of a standing or falling person from a height of his own height, i.e. on the plane on which the person was.

Such a fall happens passive(spontaneous) or active(with giving the body additional acceleration).

With this injury, fractures of the bones of the upper and lower extremities, concussions and bruises of the brain, sometimes with fractures of the bones of the skull, and ruptures of internal organs (rarely) occur. External injuries at the site of impact are limited to abrasions, bruises, and with a hard impact surface, in addition, bruised wounds. Consider the most typical types of damage.

Fall on the back of the head the mechanism of which is most fully studied on biomannequins, leads to the formation of cracks in the occipital bone, leading to the foramen magnum or pyramids of the temporal bone. In a supine fall, the point of impact may be at the level of the occiput, above or to the side of it, depending on the active or passive mechanism of the fall.

Brain contusions at the site of application of force are observed only in some cases, while multiple hemorrhages, foci of softening of the brain substance and subarachnoid hemorrhages in the area of anti-impact (frontal and temporal regions of the brain) are detected.

Falls on the sides of the head the most typical damage is the occurrence of cracks in the temporal bone. The degree of severity of damage to the substance of the brain is also much greater in the area of the counterblow compared to the site of the blow.

Fall on forehead is much less common and the nature of the damage is less typical, tk. they are localized mainly at the site of impact.

During the expert assessment of damage when falling on a plane It is necessary to take into account a number of related factors that affect the force of impact. These include: the presence of a previous acceleration (when the impact sometimes exceeds 2000 kg); height and body weight of a person; the presence, especially in women, of long thick hair, leading to a known depreciation and contributing to a decrease in the severity of the injury, the presence of a headgear (a hat with earflaps increased, in modeling, the impact time by 5–9 times compared to cases of falling without a headgear), shape head, in particular the shape of the occipital region.

Characteristic lesions are formed when crushed by massive objects. In cases where these objects have a large (disproportionate) plane, the integrity of the skin is rarely violated, and damage is limited to extensive abrasions and bruises with crushing of the underlying soft tissues. At the same time, they can reflect the features of the squeezing surfaces and clothing located on the damaged part of the body.

However, bone injuries are most typical for compression, especially in such bone formations as the skull, chest and pelvis. The nature of the resulting damage allows you to set the direction of the compressive forces. So on the bones of the skull, in places where compressive forces are applied, bilateral areas of small fragments of bones or two large fragments of a rounded shape are formed, surrounded by a ring of smaller ones. Between these areas, from the stretching of the bone tissue, connecting lines of fractures are formed, and from the bending of the bones, equatorial and parallel lines of fractures are formed.

With chest compression bilateral direct and indirect fractures of the ribs along many vertical lines are formed. For direct fractures an oblique direction in relation to the length of the rib is characteristic with a displacement of the fragments inward, while the pleura and lungs are injured.

Indirect fractures have a transverse direction, and the fragments are displaced to the outside of the body (and therefore the parietal pleura is not damaged), the edges of the fragments are even or finely serrated.

Unlike hitting, with compression of the pelvic bones multiple symmetrical bilateral fractures occur.

Direct impact of traumatic objects on internal organs causes their damage in the form of ruptures, separations, displacements or complete destruction.

Death can result from mechanical asphyxia from compression of the chest and abdomen , even without pronounced anatomical damage.

In a forensic medical examination of injuries with blunt objects, the expert can qualify the severity of the bodily injury, supplement and clarify the circumstances of the incident, the testimony of the victim, the accused and witnesses.

Classification of hard blunt objects Hoffmann E.R. (Hoffmann E.R.), 1879.

1) stupid;
2) blunt;
3) prints.

Classification of blunt solid objects (Bokarius N.S., 1930)

1) objects with wide planar surfaces in contact with the body only partially;
2) objects with a surface having linear contact (between converging faces);
3) objects with a small impact surface, which can be completely reflected in damage.

Classification of blunt solid objects (Slepyshkov I.V., 1936)

1) blunt;
2) flat;
3) cylindrical;
4) objects with an indefinite surface.

Classification of blunt solid objects (Popov N.V., 1938)

I. Natural human weapons (fingers, fist, palm, etc.).
II. Hand tools
- 1) objects with a flat surface (with widespread, limited and mixed effects);
- 2) objects with a rounded surface (cylindrical or spherical);
- 3) objects with an angular edge, prismatic (dihedral), pyramidal (polyhedral) and conical angle;
- 4) objects with an uneven surface.
III. Larger items (car parts and animals).

Classification of blunt solid objects (Raisky M.I., 1958)

1) objects with a flat, more or less wide surface;
2) objects with a blunt surface and corners forming ribs;
4) cylindrical objects of small diameter.

Classification of solid blunt objects Mukhanova A.I., 1969.

1) objects with a flat predominant surface (slab, wide side of the board, etc.);
2) objects with a flat limited surface (hammer, ax butt, narrow side of the board, rail, etc.), including rectangular surface, oblong, triangular, round, other flat and embossed limited surface;
3) objects with a spherical surface;
4) objects with a cylindrical surface;
5) objects with a trihedral angle;
6) objects with a rib or dihedral angle (rectilinear or arcuate rib and rib of another shape).

Classification of blunt solid objects (Charny V.I., 1976)

1) a large flat surface (board, stove);
2) a large spherical surface (weight, cobblestone);
3) cylindrical surface - objects with a large long and small diameter (stick, crowbar, round rod);
4) elongated faceted surface with a rib - objects with a large length and small diameter
(rod, bar);
5) a small flat surface (face) with ribs (hammer, ax butt, rod end); 6) corner or protrusion of a faceted object (iron, brick, bar, etc.).

Classification of solid blunt objects (Popov V.L., 1980)

A. Limited traumatic surface of a blunt object

1) flat - triangular, square, rectangular, polygonal, oval, round, other flat shape;
2) angular - in the form of a dihedral angle (ribbed), in the form of a trihedral angle (vertex), other types of angles (vertices) of polyhedra;
3) curve - spherical, cylindrical, other types of curved surfaces;
4) combined - combinations: flat and curved, flat and angular, curved and angular.

B. Unlimited traumatic surface of a blunt object