Like the joint capsule, tendons are high in collagen fiber content. Tendons also benefit from the use of ultrasound accompanied by stretching. After injury, tissues begin the process of repair. Scar tissue is mechanically inferior and adheres to bone or skin or to tendons and tendon sheaths. Scar tissue prevents the normal motion of body tissues that should occur with movement.
Scar tissue is less capable of absorbing stress forces before tearing.
Clinical evidence exists of the softening of scar tissue due to a relaxation in peptide bonds after the application of ultrasound. Splints, or exostosis of the interosseous ligament, often occur between the second and third or third and fourth metacarpal bones. Splints are associated with a single traumatic episode or repeated microtrauma associated with weight bearing on imperfectly positioned bones during growth. I have often heard it said that therapeutic ultrasound facilitates calcium reabsorption, reducing the splint size. However, attempts to absorb bone selectively have not been successful and this method could cause more inflammation and damage.