"We can't just attack our triceps with the latest and greatest exercise off Instagram," says Ebenezer Sameul, C.S.C.S. "Very ...

How to do it: Get on all fours with your hands under your shoulders—holding light dumbbells—and your knees under your hips.

The movement requires substantial internal rotation at the shoulder – a movement you want to avoid when possible. Instead, stick to the standard dumbbell skullcrusher. Tuck your elbows in tight ...

The movement requires substantial internal rotation at the shoulder – a movement you want to avoid when possible. Instead, stick to the standard dumbbell skullcrusher. Tuck your elbows in tight to the ...