The worst effect a current of 159mA is likely to have on the human body is _____.

A current of 159mA can have significant adverse effects on the human body. At this level, painful shock and loss of muscular control are particularly likely due to the physiological response to electric current passing through the body.

When current flows through the body, it can interfere with the nervous system's ability to transmit signals, leading to involuntary muscle contractions or an inability to control muscles effectively. This can result in not only pain but also a lack of coordination and control, making it extremely dangerous in situations where muscle control is necessary, such as operating machinery or trying to escape from the source of electricity.

While lower levels of current, such as those less than 10mA, might only cause mild sensations like tingling, and higher currents may lead to severe injuries like burns or fatal electrocution, the specific range around 159mA falls into a category where the immediate impact on muscle control and pain is very pronounced. It is essential to recognize the serious implications of such a current level, as it can lead to dire outcomes in an emergency situation.