The twang is pronounced as a very subtle and even crackling sound. It is similar to the sound produced when twirling a tuft of hair in the ear. It is characterized by a short, fine, intermittent, equal and uniform size sound. Etiology: Clostridium perfringens is a Gram-positive anaerobic bacillus, with P. aeruginosa (Weiss), B. edematosa, and B. cloacae as the main, followed by B. cloacae and B. histolytica, etc. The gas gangrene seen clinically is often a mixed infection of more than two pathogenic bacteria. Clostridium perfringens is widely present in soil and human and animal feces, so it is easy to enter the wound, but does not necessarily cause disease. The occurrence of gas gangrene is not determined solely by the presence of B. pneumoniae, but more by the body’s resistance and the condition of the wound, i.e., the need for an anoxic environment conducive to the growth and reproduction of B. pneumoniae. Thus, water loss, massive blood loss, or shock with extensive tissue necrosis in the wound, deep muscle destruction, especially in thigh and hip injuries, shrapnel retention, open fractures or with major vascular injury, and prolonged use of tourniquets predispose to gas gangrene.