Deltoid Abduction of the shoulder (moving the arm outwards and away from the body) Outward arm action in a jumping jack Rotator cuffs A group of stabilising muscles ... in front of the body ...

A new study shows the tradeoff between power and efficiency in muscles is governed by proteins that form a molecular tuning ...

In her new book, “On Muscle,” Bonnie Tsui investigates the other stuff our thews remember—like how to grow when you exercise.