Today's post is about the difference between these two muscles and how the tricky rectus femoris (quadriceps) muscle can sometimes get mixed up with one of these guys. (glute min)
The rectus femoris can sometimes have a 3rd head. I know! News to me too. It's not all the time, but worth noting. All of them with 3 heads had attachments with the glute minimus onto the greater trochanter. This suggests a working relationship.
Not only is the glute minimus and abductor and flexor, depending on the hip position it is an internal and external rotator. The glute min also has attachments into the hip capsule. They retract the hip capsule preventing capsular impingement.
The more the hip is brought into flexion the more the anterior portion of the glute min becomes an internal rotator.
From all this it appears that the main function of the glute min is to stabilize the hip while in extension. It does this functionally with the posterior part of the glute min.
Now how does this affect the runner with hip pain? First distinguish where the pain pattern is. Hip flexion, or extension? Under load, passive or active? Feeling of weakness with foot strike? Pinching with hip flexion? Know the anatomy and function and you can figure out whats not working that can be leading to pain.
Here are two great articles dealing with the Glute Minimus and the 3rd head of Rectus Femoris.