It would be reassuring to hope that the sudden twitching in your index finger was caused by a recent bang to your elbow, since ALS can cause twitching in various parts of the body.
If you get banged in your elbow – either by accidentally bumping it hard into a hard surface, or something making hard contact with it such as a kick in a karate class, it will surely hurt.
Hopefully there won’t be a bone fracture or a twisting-type movement involved in the injury that can damage the ligaments.
Banged Elbow and Twitching Index Finger
“A banged elbow can cause the sensation of hitting your ‘funny’ bone, which is an irritation of the nerves that run along the back of the elbow,” says Arielle Levitan, MD, board certified in internal medicine and co-founder of Vous Vitamin LLC and co-author of “The Vitamin Solution: Two Doctors Clear the Confusion About Vitamins and Your Health.”
Dr. Levitan continues, “Most typically this causes numbness and tingling of the pinky and fourth (ring) fingers, but in certain cases can cause twitching of those fingers or other fingers from nerve irritation. This is usually short lived and goes away on its own within a few hours.”
Because the “funny bone” nerve (ulnar) distributes into the pinky and most of the fourth finger, it is unlikely that twitching of the index finger would be a direct result of a bang to the elbow.
So what most likely could explain the sudden twitching of your index finger?
One possibility is repetitive use with it, such as handling a computer mouse.
If you haven’t been using a mouse lately or that much, think of anything that could have overworked the finger, such as prolonged knife use in the kitchen, rock climbing or playing a musical instrument.
However, the twitching in an index finger might not have an obvious cause, not any more than a sudden twitching of a toe or muscle in the back of the leg or the lower eyelid might have an obvious cause. Most causes of twitching muscles are benign.
Dr. Levitan is board certified in internal medicine and has a special interest in women’s health and preventive medicine.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.