The glutes, quads, and hamstrings are the body's biggest muscles (butt and thighs). For baseball players, or any athlete, they're the most important muscles along with the core muscles.
Too many youth players rely too much on their upper body to try and generate velocity. The sooner your young one can figure out how to utilize his/her lower half, the better off he/she will be.
Youth players typically aren't lower half dominant for a few reasons: • They may have never been told about the benefits of leg strength; • They may be too weak in their lower half to effectively engage these muscles; • They don't know how to properly use and maximize their leg strength.
Leg strength is top of the list on ways to increase arm strength. Your legs should lead and carry your body in all aspects of baseball, from pitching to hitting and fielding to base running.
1) Double-leg squat with isolated single-leg squat