Tight hip flexors, especially a deep muscle called the psoas, can silently stress your spine. Here's why this muscle deserves ...

Those wings would also need flight muscles wrapping around from the chest to the back. Related: What if humans had tails? According to Habib, bat-like wings would make more sense on humans.

Bingo wings, the rather unflattering name given ... often referred to as just 'triceps', this muscle lays along the back of your upper arm and helps with forearm extension. Anconeus: a smaller ...