Or from Latin baculum a stick, because the squire would practice with a staff, not a sword. Meaning evolved from knight in training to young unmarried man (early 14c.). Bachelor party as a pre-wedding ritual is from 1882.
A transcutaneous electrical nerve stimulation (TENS) unit is a device that sends small electrical currents to targeted body parts. These currents are used to relieve pain. Some TENS units are designed for use in a hospital or healthcare facility.
TENS has always also been seen as a form of relaxation therapy, similar to a vibrating massager, but itâs probably a minor effect. It doesnât seem to be able to prevent (for instance) jaw muscle clencing in TMJ syndrome.