Muscle “Cramps” vs Muscle “Spasms”
Dr. Bruno’s Post: CRAMPS vs. SPASMS
A muscle CRAMP is a short-lived, very painful, involuntary contraction of an entire muscle or a relatively large portion of a muscle, usually a leg muscle and sometimes a forearm muscle. Who hasn't had a screamingly painful cramp of the calf muscle that pulls your toes downward and forces you to stand to stretch it out?
A muscle SPASM feels hard, sometimes as hard as bone, and can be as small as an M&M or as big as the entire side of your neck or your low back. No one knows what spasms are or why they can hurt so badly! Spasms seem to be muscle fibers in a small area contracting into a dense knot and usually occur in postural muscles in the neck and back. But, in a 1990 study we did, there was NO relationship between how hard a muscle spasm was, muscle electrical activity and pain. So, a small, not-so-dense spasm in a neck muscle can cause a headache that puts you in bed for hours, in a dark room after driving the porcelain bus. But a large, dense rock of a spasm in your neck or back may not hurt at all even when a physical therapist puts her thumb in it.
Bottom line: Muscle OVERUSE causes cramps and muscle MISUSE (e.g., poor posture) causes spasms.
Look in the Index of the Encyclopedia of Polio and PPS under the topic: Muscle Pain, Muscle Spasm for more information on preventing cramps and spasms.