Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...

After a grueling CrossFit workout on a hot Summer morning that involved kettlebell swings, goblet squats, and about 100 walking lunges, my lower body was toast. But what was weird was that my left ...

We are born with a certain number of muscle cells, also known as muscle fibers. Research indicates that we cannot increase our muscle fiber number, but with systematic strength training we can ...

Bradycardia and a pectoralis twitch in a pacemaker patient Surgery is required for a woman whose right ventricle was perforated by the tip on the lead of her permanent pacemaker. Ms. K, age 50 years, ...

Few sensations feel as weird as when your body decides to do its own thing. Muscle twitches, hiccups, and bloody noses out of the blue can make you wonder exactly who's in charge. Here, the reasons ...

Many people with multiple sclerosis have stiff muscles and spasms, a condition called spasticity. It happens mostly in the muscles of the legs and arms, and it may keep you from moving your limbs ...