Muscle Contraction

The two main processes involved in muscle contraction are cross-bridge cycling and the length-tension relationship, which normally function to maximize contraction in the muscle. Beginning with the activation of a motor unit, the ions flow from the motor unit towards the muscle fibers that it innervates by the motor neuron in the same way as a normal muscle would. However since the tissue is damaged, the force that is generated by these muscle fibers will not be as great, leaving the fibers less effective. Now, there is a situation in which the myosin head is damaged and there are less actin binding to less myosin effecting the force production. The length tension relationship is dependent on the number of cross-bridges that are formed, which decreases when they are not generating at the usual amount. In relation to the length-tension relationship, when a muscle is contracting at an angle in which the muscle should have greater force, it will not because of the lack of actin-myosin overlap. So when the myosin head pivots, there are now less pivoting myosin heads. A major cause of this deviation is due to a lack of calcium flooding into the muscle cell. If there is not enough calcium for the troponin to bind to in order to expose the
Prolotherapy is an irritant that is used to stimulate regeneration. According to the American Association of Orthopaedic Medicine, it “stimulates the body’s natural healing processes to strengthen joints weakened by traumatic or over-use injuries”, repairing the damaged tendons by producing new fibrous tissues. This is done by injecting an irritant solution directly on the torn ligaments on the shoulder. Prolotherapy works by stimulating satellite cells in an attempt to proliferate the injured muscles. These satellite cells are activated by the disruption in muscles cells from an injury, and are stimulated by growth factor hormones to increase muscle fiber size by regulating the cell activity. Growth factor hormones including hepatocyte growth factor, fibroblast growth factor, and insulin-like growth factor (I and II) work in various ways to repair and regrow the muscles. The satellite cells will fuse together which will increase hypertrophy, they go through this process to form new fibers and repair the damaged