Painful moment a man's muscle cramp writhes like an alien creature

The painful video of a California man suffering from a cramp in his leg has gone viral.

Angel Bermudez posted the 50-second video of his undulating and unusual muscle cramp to his Facebook.

The footage shows the muscles contracting as if they were alive.

Bermudez is clearly in pain as he grunts and moans, "oh my god it wont stop".

Bermudez had just left the gym and was sitting in a car when the cramp started.

The Facebook post says: "After the workout. Start to relax and then this happens. F******g cramp. Look at this s***. Painful yes it was."

The muscle cramp could have been caused by a number of things.

Angel Bermudez filmed his calf muscle going into spasm after a gym workout. Photo / Angel Bermudez

It's possible Bermudez was dehydrated after his workout, causing the painful episode.

According to WebMD, "A muscle cramp is a strong, painful contraction or tightening of a muscle that comes on suddenly and lasts from a few seconds to several minutes."

The comments went wild offering sympathy and tips for Bermudez. One woman suggested Bermudez put mustard on the cramp and said that tons of athletes do it. And in fact, it might work!

Cramps can be caused by a deficiency in acetylcholine, the neurotransmitter that stimulates muscles to work. Mustard contains acetic acid, which helps the body produce more acetylcholine.

Bermudez replied to one comment saying, "Looked like a god damn alien in my damn leg was gonna bust out".

What To Do When a Muscle Cramp Strikes

• Stretch and massage the muscle

• Take a warm bath or shower to relax the muscle

• Drink plenty of fluids

• Put a hot or cold pack on it

• Take over the counter pain medicines

• Put mustard on it

• Eat food high in potassium such as bananas