Push-ups can be a challenge for the best of us. But many women struggle to do them, even after months of training in the gym.

So when a so-called “women’s push-up hack” started trending on social media, it’s hardly surprising that some of these videos went viral.

The hack involves making a simple tweak to the position of the hands. Instead of having the hands pointing forward in line with the body, it’s said that women should instead position their hands sideways, so their fingers are facing away from their body.

Anatomy can explain why this change to hand position can help women perform push-ups more easily. It has to do with a part of the body that you might not expect: the pelvis.

The pelvis affects the position of the arm relative to the body. In women, the angle where the forearm and upper arm connect at the elbow (known as the carry angle), relative to the pelvis, is around 15 degrees on average in women and around 10 degrees on average in men. The carry angle is greater in women in order to provide extra clearance of the pelvis when moving.

The carry angle doesn’t just impact how the bones of the upper limb connect to each other and to the torso. It also affects the direction in which the muscles contract.

This is why women may find it more difficult to do push-ups in the conventional way. By having the hands slightly further apart and turning them slightly outwards,........

© The Conversation