Medically reviewed by Brigid Dwyer, MD Key Takeaways Clonus causes involuntary, rhythmic muscle contractions when a muscle is stretched.It is often observed in conditions like multiple sclerosis, ...

Bicep tendonitis develops when a tendon in the biceps muscle swells and becomes inflamed. It usually occurs with other problems with the shoulder, such as dislocation, impingement, or arthritis. A ...