Many orthopaedic surgical disorders in joints and muscles involve, in varying degree, the soft-part structures covering or surrounding the bones. 

In many cases the state of pain is caused by changes in these structures and, in some cases, also pathological conditions in the bones.  

Ultrasound scanning is a non-invasive method used for creating two- dimensional pictures of the soft parts in joints and muscles. The apparatus is hand-held and easy to use in both static and dynamic examininations. Ultrasound scanning is quick to perform and is a relatively cheap examinination.

Considerable side effects have not ben reported and ultrasound scanning is therefor an important imaging modality in clinical work as well as in orthopaedic clinical research.