Medically reviewed by Jennifer Steinhoff, MD Key Takeaways The lumbar spine includes five vertebrae that help with mobility and stability.Lumbar vertebrae are larger because they carry the load from ...

The masseter muscle is a facial muscle that plays a major role in the chewing of solid foods. The muscle is shaped like a parallelogram, connecting to your mandible (lower jawbone) and your cheekbone.

Much like their name implies, the quadricep muscles were once thought to be a set of four muscles, with the name “quad” translating to “four or fourth” in Latin. However, it has since been discovered ...

In the orbit of the eye, also called the eye socket, the lateral rectus muscle helps move the pupil away from the body’s midline. The muscle inserts into the temporal (outer) side of the eyeball and ...

The obturator nerve is a large, multibranched nerve that travels through your pelvis to your inner thigh. This nerve helps you feel sensations like temperature and pain in your lower limbs. It also ...

Muscle twitches fall into two main types. There’s myoclonus, where a whole muscle or group of muscles twitch or spasm. Then ...