The standing clamshell is a deceptively difficult exercise and a great functional gluteal activation exercise. We use this for more advanced rehabilitation for our Chiropractic clients at Redefined Health. After becoming proficient at the clamshell exercise, which is also deceptively difficult when done properly, we move our more demanding clients to this. Assuming a ready position makes the exercise very functional for most sports and trains the often under used gluteal muscles to work in an upright position. This is great for rehabilitation or as part of a dynamic warmup or prehab strategy.