Lateral Epicondylitis or Tennis Elbow
Updated: May 5, 2022
Lateral Epicondylitis or Tennis Elbow refers to pain on the outside of your elbow. It is located where your wrist extensor muscles insert into your humerus. Here is an image to give you a better idea:

These muscles primarily perform wrist extension (bending backwards as if doing a push up), but they are also responsible for finger extension which helps with gripping and supination (turning your palm to the sky). An excellent breakdown of the anatomy is provided by the American Academy of Orthopaedic Surgeons on their website here.
The role in gripping is often misunderstood, so let’s break it down in more detail. Lay your arm down next to you with your palm facing down. Try to make a fist. You will probably extend your wrist naturally to do so, because these muscles play a role in tensing and stabilizing grip strength.