Poisonous Plants and Related Toxins edited by Thomas Acamovic, Colin S. Stewart, T. W. Pennycott

1. Seminar On Topic,
“Biomechanics of Injury”
Presented By,
Palash Mehar
M.Sc.(Forensic Science)Part-I Semester-I
Academic Year:- 2019-2020
Government Institute of Forensic Science,
Nagpur.

2. Injury
“Injury”—
The word “injury” denotes any harm whatever
illegally caused to any person, in body, mind,
reputation or property.

3. Classification Of Injury

4. Factors which influence the mechanism of injury,
1. The amount of force applied which depends on mass of the object and
speed.
2. The distribution of force over the surface of the body.
3. The transfer of the force through the body is a factor which contributes to
the wounding power. If the wounding object is eg. Perforating Bullet
pass through body the amount of damage is less as compared to
Explosive Bullet.
4. Nature of object/weapon.
5. Nature of the target tissue affected i.e. Muscle, bone, hollow organ like
intestine, skin etc.
6. Conditions under which the energy is discharged.
7. Direction of the force which adds up to the wounding.
If the movement is towards the direction of the force the damage is less
and if against the direction of the force the damage is more eg. Catching
a cricket ball.

5. Mechanisms of injury
Physical laws are involved in the causation of mechanical
injuries.
Newton’s First Law:-
“Every objects remains in its state of rest or uniform
motion until that state is disrupted by an external force.”
Similarly wounds are produced when a moving object
changes the state of rest of tissue or when the motion of tissues is
changed by meeting a force of resistance.
When force is applied to any part of the human body, the
cellular components of the tissues are set in motion and are replaced
from their original position resulting in a discontinuity or wound.

6. Injury Biomechanics
Injury is caused by penetrating or non-penetrating blows to the body, and the
energy delivered and the area of contact are important determinants of the
injury.
Penetrating injuries
Non-penetrating injuries
Biomechanics involves a variety of disciplines, including
engineering, physiology, medicine, biology, and anatomy.

7. Contd.
Crushing deformation of body (left), compression of the body and injury when the crush
exceeds elastic tolerances;
Impulsive impact (center), high-speed impact with injury when violence exceeds viscous
tolerance; and
Acceleration of the skeleton and tearing of internal organs, because of their
inertia(right)
Three principal mechanisms of impact injury:

8. Contd.
 Stretch of vessel can tear tissue (partial tear shown) with loss or
containment of blood.
 Opposing forces across vessel can cause shear injury (complete tear
shown) with or without loss of blood.

9. Contd.
Vessels beneath skin can be torn by stretch or shear with
laceration of skin, resulting in bruise, or contusion

10. Major Subdivisions of the Field of Impact
Biomechanics
(i)Injury mechanisms
(ii)Response to impact
(iii)Human tolerance to impact
(iv)Technology assessment
The field of impact biomechanics could be divided into the
following four categories (Viano et al. 1989),

11. Interpretation from injury
• Nature ,type, size and shape of the injury
• Position of injury or site of impact
• Direction of force
• Manner of injury may be known from its distribution
• Pattern of injuries are helpful in connecting the crime with the
object which produce them.
• Aging Injuries
• Weapon used by criminal
• In open wounds, dirt, dust, greace or grit are usually present
which may connect the injuries to the scene of crime.
• The direction and dimension of wound indicates the relative
position of assailant and victim.

12. Case Study
A dead body of a male aged about 50 years was found in the hotel near Bhopal.

13. References:-
1. Albert I. King, Book on “The Biomechanics of Impact Injury-Biomechanical
Response, Mechanismsof Injury, Human Tolerance and Simulation”
2. Editors Jeffrey S. Kreutzer, John DeLuca, Bruce Caplan, “Encyclopedia of
Clinical Neuropsychology”
3. Siddheshwar Forensic science book by Dr. Satish Shindadkar
4. Forensic Medicine by Umadethan.
5. https://www.ncbi.nlm.nih.gov/books/NBK217482/
6. Wikipedia search for injury.
7. Systematic Analysis of Injury: A Case Report by Dr. Jayanthi Yadav, Dr. B.K.
Athwal, Dr. B.P. Dubey Assistant Professor, Department of Forensic Medicine,
Gandhi Medical College, Bhopal-462001.

14. THANK YOU!