Mechanical Injuries.pptx

Mechanical Injuries

1. MECHANICAL INJURIES Dr. JINESH P. S. 10/08/2011 Dr Anamica Chakraborty Senior Resident Dept. Of Forensic Medicine

2. CONTENTS :

3. INJURY : ASSAULT : THE UNLAWFUL PLACING OF AN INDIVIDUAL IN APPREHENSION OF IMMEDIATE BODILY HARM WITHOUT HIS / HER CONSENT HURT:

4. 2. Thermal injuries- Due to cold – a) Hypothermia b) Frost bite c)Trench foot d) Immersion foot Due to Heat – General effects ---- a) Heat hyperpyrexia b) Heat exhaustion c) Heat cramp Local effects---- a) Burn b) Scald

5. 3. Chemical injuries - Corrosive acids Corrosive alkalies 4. Physical agents – Electricity Lightning X-ray, UV Rays Radiations

6. TYPES :

7. EXAMPLE By fingernails (throttling) By thorns By tip of knife

8. SCRATCHES OVER NECK

9. Show multiple linear furrows. BRUSH BURN (FRICTION BURN)

10. GRAZE ABRASION

11. By crushing of epithelium due to pressure & friction

12. Eg . – R adiator grill impression on skin of victim of RTA, Beating by a chain Tire marks in run over accidents Muzzle impression

13. PATTERNED ABRASION

14. SEAT BELT INJURY

15. Time Colour Cause Fresh abrasion <12 hrs Bright red non scab Oozing capillary blood 12-24 hrs Bright red scab Dried up lymph & blood 2 to 3 days Reddish brown scab 4 to 7 days >7 days Dark brown scab, Epithelisation starts Scab dries, shrinks and falls off leaving depigmented skin Peripheral healing with shrinkage of scab New epithelium formation

16. P M ANT BITE MARKS

17. MEDICOLEGAL SIGNIFICANCE

18. CONTUSION or BRUISE

19. Nature and severity of the force Vascularity of the affected area Number and size of the blood vessels involved Condition and size of the blood vessels involved

20. Predisposing factors : Sex – Age – Colour of the skin – Diseases – Chronic alcoholics – Easily bruises – Cutaneous vasodilatation

21. Time Colour Cause Fresh / few hours Red Oxy- Hb Few hours -3 days Blue Deoxy-Hb 4 day Brown Haemosiderin 5- 6 days Greenish Haematoidin 7 – 12 days Yellow Bilirubin 2 wks Normal Pig. removed by phagocytosis

22. Eg . - Contact fire arm injury Motor car Stomping Blow by hammer or rod Kicking

23. SLAP MARK - CHEEK

24. Objects like belt Two parallel linear contusions separated by a relatively pale, undamaged section of skin

25. By applying juice of irritant plant like C alotropis , Marking nut ( Semecarpus anacardium ), Lal Chitra ( Plumbago rosea )

26. DIFFERENCES TRUE BRUISE FALSE BRUISE Colour Changes with time Dark brown Margin Location Diffuse, irregular Anywhere Well defined, Covered with vesicles Accessible parts Content Haematoma Serous fluid Local reaction Signs of inflammation over the bruise Surrounding area Vesicles Absent Present Chemical test ( - ) ve (+) ve for vesicant Itching No Yes

27. PM Staining Bruise Cause Site Collection of blood Incision Colour Effect of pressure Microscopically

28. MEDICOLEGAL SIGNIFICANCE (CONTINUED….)

29. Which one is of greater value- Abrasion or Bruise ?????

30. 1. Blow with hard blunt weapon 2. Fall from height on rough or projected surface 3. By accidents – RTA 4. By fist blow or kick 5. Over stretching of the skin Mode of production :

31. Characteristic of lacerated wound : 1. Margins – 2. Subcutaneous and deeper tissues – 3. Gaping – 4. Tissue bridges – 5. Less bleeding 6. Bruising -

32. 7. Hair bulbs crushed or torn 8. Not usually correlates with the shape and size of weapon 9. Commonly infected 10. Mud, sand, glass, brick particles inside the wound

33. TYPES – 1. Split 2. Stretch 3. Avulsion 4. Tear 5. Cut

34. Medicolegal aspects : 1. Always caused by blunt force injury 2. Homicidal , accidental or suicidal 3. Defence wound 4. AM and PM laceration

35. Thank you