The majority of skeletal muscle injuries that occur in sports are the result of indirect strain or direct blunt force trauma. Other forms of muscular injury, such as lacerations, ischemia, and infections, are not commonly seen in athletics. The amount of research in the area of muscle injury and repair is growing, but we do …
What is a Laceration Wound? A laceration is a wound that occurs when skin, tissue, and/or muscle is torn or cut open. Lacerations may be deep or shallow, long or short, and wide or narrow. Most lacerations are the result of the skin hitting an object, or an object hitting the skin with force. Laceration …
We perform all arthroscopic shoulder procedures in the lateral decubitis position under general anesthesia. Five to 10 pounds of balanced suspension are used with the arm in 20 degrees to 30 degrees of abduction and 20 degrees of forward flexion (Star Sleeve Traction System, Arthrex, Inc., Naples, FL). Diagnostic glenohumeral arthroscopy is performed through a …
What is Musculotendinous Junction? The myotendinous junction is the interface between muscle and tendon, and it allows the force generated by muscle contraction to be exerted on the skeleton to enact limb locomotion. To maximize the junctional surface area, a region of highly folded membranes in a fingerlike arrangement exists. This increases the surface area …
Myosin, actin, tropomyosin, and troponin are the four major structural proteins that make up muscle. These proteins form the foundation of the basic contractile unit known as the sarcomere. The banding pattern seen in striated skeletal muscle comes from the repeating arrangement of two myofibrillar filaments, thick filaments and thin filaments. Thick filaments are composed …
Each muscle fiber is surrounded by its plasma membrane, or sarcolemma. Within this sarcolemma lie quiescent satellite cells that are essential for the repair of muscle after injury. Following muscle injury, inflammatory substances are thought to stimulate these satellite cells to undergo proliferation and differentiation into new muscle fibers. Fibers are further divided into smaller …
Palpation of the deltoid muscle The deltoid muscle is easy to recognize. It forms the most important muscular mass of the shoulder and is responsible for its round look. The anterior portion overlies the anterior border of the acromion and the lesser tuberosity. The middle portion lies over the lateral border of the acramion and …
