Electrotherapy is the word used for all kinds of machines physiotherapists use to help you.
Ultrasound therapy, for example, is used to stimulate the body to heal faster in a specific area and decrease your pain. It used to be overused in the past and nowadays a lot of NHS clinics got rid of them.
But ultrasound therapy has its place in physiotherapy treatment. It helps reduce bruising and swelling in and around muscles, tendons and ligaments. It also works extremely well for acute bursitis.
Another electrotherapy is TENS, which is used to ease pain. When applied, it affects the nerves and calms the pain signals. It's very effective for patient with back, neck and shoulder pain.
Last but not least, electrostimulation is used to help muscle strengthening. Patches are applied on the muscles you want to work on and a small machine helps you contract them. We tend to use this technique for patients who struggle to use their muscles after an operation.