The amount of shock current is based on the voltage and is based on Ohm’s Law. Greater the voltage means greater current, so there is greater danger from higher voltage. Very low shock currents (1 mA) can cause tingling. Higher shock currents (above 10 mA) can paralyze or “freeze” muscles, preventing a person from releasing a tool, a wire, or other object. A typical home circuit breaker trips at 15,000 mA or 20,000 mA.
The severity of the injury also depends on the length of time of the shock. If the shock is short, and the current is low, it may only be painful. If an equivalent level of current flows through the same path and the shock lasts a longer duration of time, it could be fatal.
In cases where the causation or severity of injury is called to question, Vista Engineering consults our own in-house biomechanical engineers to address these technical issues.
Electricity takes advantage of all available paths. The primary flow of electrical current flows in the path of least resistance, but lesser flows of electrical current will occur in other available paths. Factors that influence the resistance of a body include: contact surface area, skin moisture, contact pressure, and the conductivity of the body parts (skin, blood, muscles, bones, joints, and other tissues/organs). Current through the heart may result in tissue damage, fibrillation, or cardiac arrest.
The engineers at Vista Engineering regularly investigate electrical shock injuries and electrocutions to determine their cause. Investigations normally include an evaluation of equipment installations in accordance with electrical and safety codes, product/appliance/equipment designs, maintenance/repair issues, possible defects, and the adequacy of warnings and instructions.
Our engineers have experience in electrical design, industrial automation, electrical controls, machinery and workplace safety. We apply expertise to forensic casework involving electric shock injuries, fires of electrical origin, and failure analysis, as well as various issues involving electrical systems safety and performance.
Several members of the team regularly investigate electrical shock incidents.