Posterior Gluteus Medius (AKA The Clam): Don’t ban it, just do it better

Exercises for posterior gluteus medius have been eloquently termed “the clam”.

There are a few problems with the traditional clam:

Piriformis is also a hip external rotator. It reportedly changes its axis of rotation between 45°-65° of hip flexion. Many years ago, an old colleague and I looked at piriformis under real time ultrasound during side lying hip external rotation and indeed it did not increase cross sectional area above 65°. It was variable between 40-60°. So are you truly biasing posterior gluteus medius if you do a clam in the traditional position? Maybe, but maybe not. I recommend starting exercises for posterior gluteus medius in 65° or more hip flexion.
Hip instability (or microinstability). From what we know about the lumbar spine, there is considerable variability in control mechanisms. Obviously, the lumbar spine is more complex since it has to concurrently consider spinal control with respiratory function and continence. However, this can be summarized simply as “too much control and too little control”. With too much control it seems that there is increased muscle activity and spinal compression. If this happens in the hip, there could be increased muscle activity of other muscles during the gluteus medius exercise as the central nervous system prioritizes translation control of the femoral head. If this is the case, maybe exercises for translation control are the priority to start? This is an example for psoas major: https://www.researchgate.net/publication/262912731_Rehabilitation_of_the_stability_function_of_psoas_major
Pain is involved in muscle inhibition and atrophy. There are different subdivisions of gluteus medius (e.g., superficial and deep). With prolonged pain, it may be possible for these to have inhibition or atrophy. If this is the case, more load or facilitation is required for rehab. A thuraband could be used around the distal femurs or the exercise in the next post (but consider point 2).

So in prescribing an exercise for posterior gluteus medius consider why you are doing it and is it the most appropriate exercise for this stage of their rehabilitation.

Do they have nociceptive pain?
Is this type of exercise the clinical priority for them right now (e.g., is high kinesiophobia present)? https://www.researchgate.net/publication/341408517_Is_one_screening_tool_enough_to_identify_the_diverse_spectrum_of_behavioral_factors_that_may_influence_a_poor_outcome_in_musculoskeletal_pain
Can they learn (to monitor their pelvic rotation)?
Is a posterior gluteus medius exercise addressing a tissue loading mechanism (that you feel is involved in creating the patho-anatomical diagnosis)? And is the priority at this stage of their rehabilitation.
Are they likely to respond (e.g., how high have they scored on the NISE screening for low grade systemic inflammation)? https://www.researchgate.net/publication/339127713_Are_co-morbid_medical_symptoms_associated_with_poor_response_to_sub-classification_based_management_of_chronic_low_back_pain_A_retrospective_case-control_s

Note: the traditional “clam” is used for another purpose in motor control circles. As you externally rotate the hip, there is often lumbo-pelvic rotation. This changes the axis of rotation and you may no longer be biasing posterior gluteus medius, so to make it a specific motor control exercise, it would only be performed within the range the rotation can be controlled.

I don’t advocate blindly giving an exercise without applying logic to it. If you do an exercise for posterior gluteus medius I recommend starting it in 65° or more hip flexion.

If you do not want to start with this or are unsure, there is another option of loading posterior gluteus medius which addresses the principles of specific motor control and other approaches. That will be in another post.