An exercise that we incorporate a lot into our warmups are “Clams” or the Hip External Rotation Clamshell Exercise. I’ve borrowed some of Mike Reinold’s information before on the Shoulder W post and I’ll use some of his information and video demonstrations again to discuss the clamshell exercise. Just as the shoulder W and the “no money” drills are excellent ways to strengthen and prepare the shoulder for external rotation, the clamshell exercise strengthens and prepares the hips for external rotation. You can think of this as pushing your knees out as you pull yourself deep into a squat. In terms of simplicity and effectiveness there aren’t many exercises that top the clamshell.
“Why is it so valuable,” you ask?
In Mike’s article here he mentions that EMG studies have shown that the clamshell exercise, if done properly, produce a good amount of muscle activity in the gluteus medus and maximus, which is very helpful especially on squat days. He gives a few pointers for performing the movement:
Here is Mike’s video of how to perform the Clamshell exercise with the hips flexed.
Here is Mike’s video of how to perform the Clamshell with the hips neutral.
Finally, a more advanced version of the clamshell exercise has the hips at neutral and holding a side plank position while simultaneously performing the movement. See the demonstration below.
Marcus’ Prowler Challenge