You will need few electric wires, a voltmeter, a ammeter, variable resistor, a resistor, a switch, and power supply.

Connect one end of the switch to the right side of your hip, and the other to the left side.

Increase the Volts as per your pain and requirement.

Remember, the voltage is directly proportional to the current. So do not increase it too much, like 440 Volts.

Kindly see the diagram below for your kind perusal.