In the second of a series of exercise featuring BOSU, Brian demonstrates another exercise that challenges the hips and core.
Note: This is an advanced core and hip strengthening exercise. Clients should already be able to sufficiently perform side planks and clamshell exercises independently and together on the floor prior to trying this exercise.


Begin in the side lying position with the bottom forearm positioned on top of the BOSU Balance Trainer. The hips can be flexed at 45 degrees or so, or placed in neutral with the body if you wish to slightly reduce the iliopsoas contraction. The knees should be flexed to 90 degrees, and the feet should be together.


Next, rise up to a side plank position and maintain a neutral alignment of the shoulders, spine and hips. Then slowly externally rotate the top thigh while keeping the feet in contact throughout the movement. Avoid allowing the pelvis or shoulders to roll back. Pause at the top and then lower back down. A cadence of 1/1/1 is sufficient for this movement.

Repeat for 10-15 repetitions or time and perform 2-3 sets on each side. The key factor in determining reps or total time should always be form. A loss of stability or premature fatigue necessitates stopping or regressing the exercise.

Application: This exercise is an excellent way to challenge higher level athletes and clients who are in need of advanced core and hip strengthening. Combining the side plank and clamshell together offers excellent activation of the obliques, gluteus medius and hip external rotators.
Performing the clamshell with the BOSU Balance Trainer further challenges core, hip and shoulder stability. While some may advocate performing this exercise against a wall, I prefer to do it in an open space to maximally challenge proprioception and stability, while also being able to observe movement flaws or compensations that may occur.
For those looking for regressions or a progression toward using this exercise I suggest the following:
Side lying clamshells with the BOSU Balance Trainer w/o plank (floor)
Bent knee side planks (floor)
Bent knee side plank with clamshells (floor) using the BOSU Balance Trainer
Side lying clamshells with the BOSU Balance Trainer w/o side plank
Bent knee side planks
Clamshells with the BOSU Balance Trainer (as pictured)
Clamshells with the BOSU Balance Trainer and a mini-band around thighs

Brian Schiff, PT, CSCS, is a licensed physical therapist, respected author and fitness professional. Currently, he serves as the supervisor at the Athletic Performance Center in Raleigh, NC. Brian presents nationally at several professional conferences and seminars on injury prevention, rehab and sport-specific training. For more cutting edge training information, subscribe to his monthly Training & Sports Medicine Update at