There is another good piece on firing the glutes here: Hamstring Dominance The phenomenon of “gluteal amnesia” is most commonly due to overactive hip flexors. When the hip flexors (psoas, iliacus, rectus femoris, tensor fascia latae) become tight from poor training and/or prolonged sitting/driving, their antagonists (gluteus maximus, primarily) tend to become weak. This mechanism is known as reciprocal inhibition. Basically, when the muscles on one side of a joint become tight, this alters the joint kinematics and shuts down the muscle(s) on the other side of the joint. Now you must be asking yourselves, what in the world does this have to do with tight hamstrings? It has everything to do with it, of course! The human body is an amazing piece of machinery and will find ways to accomplish movements regardless if some muscles aren’t functioning to their capacity. It learns to compensate and calls upon other muscles to perform the movement to ...