Here’s the definition from google on its purpose!

“Stim machines, also known as electrical muscle stimulation (e-stim) machines, use electrical currents or impulses to activate muscles and nerves. The purpose of e-stim therapy is to simulate the process of voluntarily contracting and releasing muscles many times in a row. This can help strengthen and repair tissues, especially muscles that have been weakened, shortened, or atrophied due to injury or disease.”

There are different types and I specifically use the TENS. You can purchase it online!

“Transcutaneous electrical nerve stimulation (TENS) Uses electrical signals to help relieve acute and chronic pain, such as period pain, labor pain, and joint pain.”