What Is the Trapezius Muscle? Trapezius muscles are large, paired, triangular muscles in the back of your neck and upper back. They extend down your back, but they’re mostly involved in the movements ...

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 ...

You're in the middle of your squat reps — weight in hand — and just like that, a charley horse causes your calf muscle to go rogue. When this type of muscle spasm or cramp hits, there is no mistaking ...

Add Yahoo as a preferred source to see more of our stories on Google. Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary ...