The hamstrings consist of three muscles—called the semitendinosus, semimembranosus, and biceps femoris—that enable hip extension (moving your thigh backward) and knee flexion (bending your knee).

Build stronger arms, shoulders and core muscles with this fitness trainer's five-move upper-body kettlebell workout.

You can help relieve stress, tension, and pain in your neck with these simple neck stretches that take just five minutes to complete.

UNDER the above heading in your issue of January 18, 1872, Dr. Elliot Coues describes the peculiar movements made by the bones of the wing of the bird in flexion and extension. It may interest ...

In 1999, the Eastern Association for the Surgery of Trauma (EAST) recommended bedside flexion/extension (F/E) fluoroscopy for patients with severe TBI who have normal results on three-view ...

In 2025, an extension moves the filing deadline to Oct. 15. Many, or all, of the products featured on this page are from our advertising partners who compensate us when you take certain actions on ...