logging in or signing up MECHANICAL INJURIES 1-jps dreamydews Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 1582 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: August 19, 2011 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: drsachinmp (26 month(s) ago) its really students friendly dr jinesh Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript MECHANICAL INJURIES: MECHANICAL INJURIES Dr. JINESH P. S. 10/08/2011CONTENTS: CONTENTS INTRODUCTION MECHANISM OF INJURIES ABRASION & SIGNIFICANCE CONTUSION & SIGNIFICANCE REFERENCESDEFINITION: DEFINITION Section 44 IPC “ANY HARM WHATEVER ILLEGALLY CAUSED TO ANY PERSON IN BODY, MIND, REPUTATION, OR PROPERTY”CLASSIFICATION OF INJURIES: CLASSIFICATION OF INJURIES Abrasion Contusion (bruise) Laceration Incised wound Punctured wound Firearm (Gunshot) wound FracturesMECHANISM: MECHANISM EVERY OBJECT REMAINS IN ITS STATE OF REST OR UNIFORM MOTION UNTIL THAT STATE IS DISRUPTED BY AN EXTERNAL FORCEMECHANISM: Wounds are produced when a moving object changes state of rest of tissues or when motion of tissues changed by meeting a force of resistance When force is applied to human body, cellular components of tissues are set in motion & replaced from the original position resulting in a discontinuity or wound MECHANISMNATURE & SEVERITY: NATURE & SEVERITY Properties of injuring force Velocity Mass Shape Peculiarities of area affected Elasticity Toughness Area over which force actsABRASION: Injuries involving only superficial layers of skin (epidermis and/or part of dermis) by objects coming into forcible contact TYPES Tangential abrasions – friction predominant Scratches Grazes Pressure abrasion – compression predominant Pressure abrasion Patterned abrasion ABRASIONSCRATCHES: Linear By sharp / pointed objects Removing epithelial layer EXAMPLE By fingernails (throttling) By thorns By tip of knife SCRATCHES SCRATCHES OVER NECK : SCRATCHES OVER NECKGRAZE ABRASION: Brush abrasion By rough/hard objects come into contact with skin in a sliding/scraping manner When body is dragged over a rough surface Show multiple linear furrows GRAZE ABRASIONGRAZE ABRASION (BRUSH BURN): GRAZE ABRASION (BRUSH BURN)PRESSURE ABRASION: PRESSURE ABRASION By crushing of epithelium due to pressure & friction May be associated contusion – contused abrasion TYPES Impact abrasion Contact abrasion Patterned abrasion Nonpatterned abrasionIMPACT ABRASION: IMPACT ABRASION Vertical impact force, epidermis crushed Imprint of object is stamped Eg – radiator grill impression on skin of victim of RTA, Beating by a chainBEATING WITH A CHAIN: BEATING WITH A CHAINCONTACT ABRASION: Impact force – absent Merely sustained pressure It reflect pattern of the object Eg – ligature mark of hanging & strangulation CONTACT ABRASIONCONTACT ABRASION: CONTACT ABRASIONPATTERNED ABRASION: PATTERNED ABRASION Abrasion having same pattern of agent caused it Pressure of object is vertical with negligible friction Egs Rough coir ligature Tyre marks in run over accidents Fingernail marks in throttlingPATTERNED ABRASION: PATTERNED ABRASIONSEAT BELT INJURY: SEAT BELT INJURYPATTERNED ABRASION: PATTERNED ABRASIONPATTERNED OBJECT: PATTERNED OBJECTNON-PATTERNED ABRASION: NON-PATTERNED ABRASION As frictional force increases, abrasion fail to exhibit the weapon patternCONTUSED ABRASION: CONTUSED ABRASION Depending on extent of crushing, a contused area may surround the abrasion Abraded area prominent – contused abrasionCONTUSED ABRASION: CONTUSED ABRASIONFABRICATED ABRASION: FABRICATED ABRASION By oneself / help of another person If self – only accessible parts involved – face, hands Motive may vary – serious / trivialNAPPY ABRASION: NAPPY ABRASION In infants due to excoriation of skin covered by a nappy Confused with antemortem violence Yellowish/yellowish-brown Lack apparent antemortem reactionNAPPY ABRASION/DIAPER RASH: NAPPY ABRASION/DIAPER RASHNAPPY ABRASION/DIAPER RASH: NAPPY ABRASION/DIAPER RASHAGE OF ABRASION: AGE OF ABRASION Time Colour Cause Fresh abrasion Red Oozing capillary blood 12-24 hrs Dark r ed scab Dried up lymph & blood 1, 2 days Brownish red scab 3, 4, 5 Dark brownish red scab 6, 7 Falls off scab with central area of hypopigmentation Peripheral healing with shrinkage of scab 1 month Normal New epithelium formationAGE ?: AGE ?AGE ?: AGE ?POSTMORTEM ABRASIONS: POSTMORTEM ABRASIONS Lack vital reaction Dark & leathery Scab formation absent Dermis will be pale Site – usually on bony prominence, Ant erosion on external orifices Ants may invade small blood vessels & blood may seep – D/D of abrasionP M ANT BITE MARKS: P M ANT BITE MARKSMEDICOLEGAL SIGNIFICANCE : MEDICOLEGAL SIGNIFICANCE Indicate site of contact with an object May be only external indication of a deep seated injury Patterned abrasion – connect wound with object which produced the wound Stage of healing help in determining time of occurrence – only approximate Dirt, dust, grease, sand around abrasion connects scene of crimeMEDICOLEGAL SIGNIFICANCE : Distribution give valid information about nature of crime Around nose & mouth – smothering Around breast & genitalia – sexual assault Crescentic abrasion on neck – throttling On face of assailant – struggle Possibility of skin fragments of assailant may retained under the nail MEDICOLEGAL SIGNIFICANCED/Ds: D/Ds Ant erosion Excoriations of the skin by excreta – in infants, excoriation may seen in napkin area which after death become dry, depressed & parchment like. Color – pale yellow to deep copper Pressure sores Drying of skin – scrotum – hardened reddish brown colouration resembling abrasionCONTUSION : CONTUSION IS AN EXTRAVASCULAR COLLECTION OF BLOOD THAT HAS LEAKED FROM BLOOD VESSELS DAMAGED BY MECHANICAL IMPACT OF A BLUNT NATURE, WITHOUT LOSE OF CONTINUITY OF TISSUES Usually situated is subcutaneous tissue, or may be in various internal visceraECCHYMOSIS & PETECHIAE: ECCHYMOSIS & PETECHIAE BV involved in contusion – usually small arteries, veins or capillaries Ecchymosis – contusion smaller than few mms Petichiae – punctate contusion – pinpoint contusions – haemorrhages resulting from bursting of congested capillaries as in asphyxia or bleeding points in skin in bleeding disordersMECHANISM: Extent of effusion of blood resulting from damage to blood vessels depends on Site – greater in lax tissues – periorbital area Sole & palm – minimal - Thickness of skin Reselience of the area – minimal in well yeilding anterior abdominal wall Sex – female contuse more easily MECHANISMMECHANISM: Age – children & aged are more susceptible Chronic alcoholics – Easily bruises – Cutaneous vasodilatation Boxers & athletes – Less bruising due to good muscle tone Obese flabby - bruise easily Vascularity Force applied MECHANISMSlide 50: Diseases – hemophilia, scurvy, leukaemia fair skinned – more prominent - Color of skin Deeper tissues – less prominent Gravity shifting of blood – black eye – called ectopic/percolated/migratorySlide 52: Deeply situated may manifest externally only after several hours or days – come-out bruise Black eye – Spectacle haematoma Bruise thigh - Fracture pelvis Bruise over ankle - Kick on calf muscle Bruise in neck - Fracture jaw Contusion behind ear - Basal fracturePATTERNED CONTUSION: PATTERNED CONTUSION Size & shape mirror a portion of object causing it Egs contact fire arm injury Motor car Stomping Blow by hammer or rodHEADLIGHT ON THIS MAN’S LEG: HEADLIGHT ON THIS MAN’S LEGBEATING WITH A CHAIN: BEATING WITH A CHAINSLAP MARK - CHEEK: SLAP MARK - CHEEKTRAM LINE CONTUSION: TRAM LINE CONTUSION Objects like belt Two parallel linear contusions separated by a relatively pale, undamaged section of skinTRAM LINE CONTUSIONS: TRAM LINE CONTUSIONSBITE MARK: BITE MARK May be patterned abrasion or contusion or even laceration It photographed with a scale Diapositive transparent photo of biting pattern of dental impression is superimposed on photograph of bite mark & compared Digital imaging & 3D data Sterile swab collected from bite mark & tested for ABO grouping & DNA analysisOLD BITE MARK: OLD BITE MARKARTIFICIAL BRUISE: ARTIFICIAL BRUISE By applying juice of irritant plant like calotropis , marking nut ( Semecarpus anacardium ), Chitra ( Plumbago zeylanica ), Lal Chitra ( Plumbago rosea ) Site – accessible areas if self inflictedDIFFERENCES: DIFFERENCES TRUE ARTIFICIAL Colour Red – yellow Dark brown Margin Diffuse, irregular Covered with vesicles Content Haematoma Serous fluid Local reaction Signs of inflammation Itching Vesicles Absent Seen in fingers Chemical test ( - ) ve (+) ve for vesicantAGE OF CONTUSION: AGE OF CONTUSION RBC in bruise ‘ ll disintegrate by haemolysis liberating haemoglobin which further disintegrate by tissue enzymes & histiocytes Time Colour Cause Fresh Red Oxy- Hb 1 st day 2 nd day 3 rd day Blue Bluish purple Bluish black Deoxy-Hb 4, 5 Brown/livid red Haemosiderin 5, 6, 7 Green Haematoidin 8, 9, 10, 11, 12 Yellow Bilirubin 2 wks Normal Pig. removed by phagocytosisPOST MORTEM CONTUSION: POST MORTEM CONTUSION Likely to see over forehead Severe blow within a few hours of death produce contusions in other parts Area over PMS is more susceptible Lack swelling & inflammatory reactions Edges sharply demarcatedMEDICOLEGAL SIGNIFICANCE: MEDICOLEGAL SIGNIFICANCE Nature of object used & force applied can be predicted Color change help to deduce time of occurrence – different colors on different parts of body is indicative of chronic abuse – battered baby syndrome If any doubt about antemortem /postmortem – histopathology – vital reaction if antemortemMEDICOLEGAL SIGNIFICANCE: Character & manner may be known from its distribution Bruising of arm may be a sign of restraining a person Bruising of shoulder blades indicate firm pressure on body against a resisting surface In manual strangulation – give indication of method of attack & position of assailant Bruising of thigh & genitalia – rape Dirt, sand, grease – connect scene of crime Contusion in & around nose & lips - smothering MEDICOLEGAL SIGNIFICANCELESSER VALUE : LESSER VALUE Size may not correspond to size of weapon May visible only after days May appear away from site of injury Don’t indicate direction of application of forceD/Ds: D/Ds P M S Artificial bruise ? Sun burn markSUN BURN & PMS: SUN BURN & PMSDIFFERENCES WITH P M S: DIFFERENCES WITH P M S Bruise P M S Cause Rupture of BV & extravasation Engorgement of BV due to pooling Site Anywhere Dependent parts Surface Elevated Not Epidermis May abraded Not Margins Merge with surroundings Clearly defined Histology Signs of inflammation Not Color Depend on age Mostly purple Incision Blood in cut tissue & cant wash off Blood oozes out & can wash offREFERENCES: REFERENCES K. Mathiraharan , Amrit K. Patnaik . Modi’s Medical Jurisprudence & toxicology 23 rd ed.5 th reprint. 2010 B. Umadethan . Forensic Medicine. 1 st ed.2011 V. V. Pillai . Textbook of Forensic Medicine & Toxicology. 16 th ed. 2011 K. S. Narayan Reddy. The Essentials of Forensic Medicine & Toxicology 29 th ed.2010 Krishan Vij . Textbook of Forensic Medicine & toxicology, Principles & Practice 5 th ed.2011 Jay Dix. Color Atlas of Forensic Pathology.2000 http://www.med.pdn.ac.lk/departments/forensic/BUDHUSARANAI/blast-ansr.html.6/8/2011 http://www.skinrashespictures.com/skin-rashes/sunburn-treatment-sun-burn-remedies-relief.html.8/8/2011Slide 77: Thank you “An injury is much sooner forgotten than an insult” Lord Chesterfield You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.