>Horsehoes legs are the ends of the triceps that go into the
>back of the shoulder (tri= three; triceps has 3 insertion
>points on the back of the shoulder, the muscle originates at
>the elbow with 1 attachment and it branches out).
Actually, the 'horseshoe legs' are most visible closer to the elbow end of the triceps, about halfway down the upper arm (if you look at an anatomy chart, the triceps look like they split about half-way down). The long and medial heads are on the 'outside" of the arm (as you are standing) while the medial head is toward the body. (It's easiest to see this in a men's bodybuilding magazine: look for a photo of a huge guy doing a tricep flex, and you will see the 'horseshoe-leg-appearing' anatomy.)