While the video is fictional and uses exaggerated movements for comedic effect, it's important to note that a pulled biceps femoris is a real and painful injury in horses.
Where is the muscle on horse that gets pulled in lets ride friends forever?
The muscle that is pulled in the Let's Ride Friends Forever music video is the biceps femoris. This muscle is located on the back of the horse's thigh, and it is responsible for extending the hip and flexing the stifle joint.