Which of the following is not a type of traction?

The selection of thermal as the correct answer is based on the categorization of traction types. Traction is a method used in physical therapy and rehabilitation to relieve pressure on the spine and other joints, typically involving the application of a pulling force to the body.

Manual traction involves a therapist applying hands-on physical force to decompress joints. Inversion traction typically utilizes specialized equipment to invert the body, which may help alleviate pressure on the spine through the effects of gravity. Static/intermittent traction refers to either a constant force or a rhythmic pattern of pulling that also aims to reduce muscle tension and relieve discomfort.

Thermal, on the other hand, relates to heat applications, which serve a different purpose in therapy, such as increasing blood flow and promoting relaxation of muscles. It does not involve any pulling or mechanical force on the body, which is essential to the definition and function of traction. Thus, thermal is correctly identified as not being a type of traction.