Traction just means steady pulling. It is used in medicine to straighten and align broken bones that are too difficult to align with a bandaid cast.

Fractures of the shaft of the thighbone (femur), for instance, are commonly treated by traction. Traction is also often necessary in the treatment of fractures of the spine.

Traction was also used in the treatment of severe cases of herniated disc, but is rarely used for this today. It is sometimes helpful in relieving pain in the neck or lower back.