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 ...

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 ...

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 ...

If you’ve got a lump on top of your shoulder muscle, you have a good chance of it being a trapezius knot. This type of lump in the trapezius muscle — called a myofascial trigger point — is among the ...