It is made up largely of collagen and absorbs large amounts of ultrasound energy. This absorption of ultrasound energy increases the elastic property of the collagen, making it easier to stretch. The use of continuous ultrasound at one megahertz is ideal for reaching the deep tissues surrounding joints and increasing soft tissue elasticity for improved stretching. Tendon Extensibility Tendons, the fibrous attachments of muscle to bone, can become shortened after injury. 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.