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 accomplish the particular task. And, if our glutes aren’t working properly the body will lean on its synergists (helpers) to work overtime in tasks that involve hip extension, hip external rotation, as well as deceleration of hip flexion and hip internal rotation.
The glutes’ “assisters” in movement are the hamstrings as well as the adductor magnus. And if you’re following along by now, you should be realizing that the hamstrings will be forced into during more work if the glutes are not functioning properly.
Thursday, December 30, 2010
There is another good piece on firing the glutes here: Hamstring Dominance