Trigger finger, or stenosing tenosynovitis, is a condition causing a locking sensation in the fingers due to inflammation of the A1 pulley, commonly affecting the thumb and ring finger. Risk factors include older age, diabetes, and rheumatoid arthritis, with symptoms such as pain, stiffness, and a catching sound when moving the fingers. Physiotherapy management aims to reduce pain and improve motion through various treatments including thermotherapy, massage, and exercises.