How does electricity cause injury and electric shock?

Electricity is predictable in that it will:

  1. Move in a circuit
  2. Travel a path of least resistance and
  3. Head for the ground.

Electricity will not discriminate on how it achieves these three actions, that is, it will pass through a person to flow to the earth if that is the easiest path of travel. A safe path to ground for electricity is away from your body and confined within whatever piece of electrical equipment you’re using. However, if an appliance is faulty or has a shorted wire, the electric current may try to find another path (e.g. through a person) to get to ground.

Aside from injuries sustained due to electrical current flowing through the body, other injuries can result such as falls from ladders, contact with moving machinery or injuries to other people.
Electric shock has the potential to cause fatal injury. The term ‘electrocution’ implies death due to the action of electric current.

Electric current passing through the body can cause:

  • Muscle spasms
  • Inhibition of the respiratory centre of the brain
  • Heart fibrillation (disturbance to heart beat)
  • Tissue burns and nerve damage
  • Confusion or memory loss

Muscle spasm can prevent people from releasing their grasp on electrically “live” parts and prevent breathing or shouting for help. This can cause the person to panic which in turn induces sweating. A variable that affects current flow through the body is the individual’s “electrical resistance”. Almost all of the body’s resistance is in the skin and sweating further reduces the person’s inherent resistance. (Greater resistance =
increased difficulty for electricity to pass through the body).

Ventricular fibrillation is considered the main form of death by electric shock. Essentially, it is a condition of the heart caused by the disturbance of the heart’s own internal impulses. The heart rhythm fluctuates and cannot effectively pump blood to sustain life.

First aid should be provided immediately after the person is isolated from the electric current.

Always seek further medical assistance either;

  • Immediately, by calling the ambulance or
  • as soon as possible, by attendance at a doctor even if the person has received a mild shock or only a suspected shock. This is because disturbance to the heart beat may not be readily detected by the person or during first aid.