Introduction The subscapularis muscle is a large, triangular muscle located on the anterior (front) side of the scapula (shoulder blade). It is one of the four muscles in the rotator cuff that control medial rotation and shoulder joint stability. During diverse upper-limb motions, rotator cuff muscles collectively stabilize and direct the humeral head inside the…
Introduction The coracobrachialis muscle in the upper arm is small yet elongated. It’s situated in the arm’s anterior compartment. It starts from the scapula’s coracoid process and enters the centre of the humerus’s medial surface. Its main purpose is to flex and adduct the arm at the shoulder joint. It helps to keep the humeral…
Introduction The brachialis muscle is the elbow joint’s primary flexor. It has a fusiform shape and is positioned in the arm’s anterior (flexor) compartment, close to the biceps brachii. It is periodically divided into two portions and may combine with fibres from the biceps brachii, coracobrachialis, or pronator teres muscles. Structure Origin The distal part…
Introduction The serratus posterior superior muscle is found in the back’s intermediate compartment. It has a slender, rectangular shape and is placed deep in the upper back, close to the rhomboid muscles. The rib cage is raised by the serratus posterior superior muscle and lowered by the serratus posterior inferior muscle. When forced breathing is…
Introduction The serratus posterior inferior muscle is found in the back’s intermediate compartment. It is located in the lower part of the back, beneath the latissimus dorsi. It plays a role in respiration and stabilization of the lower thoracic and upper lumbar vertebrae. Structure The muscle is placed where the thoracic and lumbar spines meet….
Introduction Serratus posterior muscles are two sets of muscles found in the upper and lower backs. These include: These muscles work together to form the back’s intermediate layer of extrinsic musculature.These muscles’ principal function is to facilitate breathing; the serratus posterior superior muscle lifts the ribs, while the serratus posterior inferior muscle lowers them. In…
Introduction The thorax muscles are a group of muscles located in the chest region that play a key role in respiration and upper body movement. The thoracic wall comprises the subcostalis, transversus thoracis, innermost intercostal muscles, external intercostal muscles, and internal intercostal muscles. During breathing, these muscles are principally in charge of altering the thoracic…
Introduction The transversus thoracis is a thin, flat muscle on the inner surface of the front chest wall. It extends from the lower sternum and xiphoid process to the inner surfaces of ribs 2–6. Its main function is to assist in forced expiration by helping to depress the ribs, thereby reducing the volume of the…
Introduction The Levatores Costarum (Latin for “lifters of the ribs”) are small, deep muscles of the back that assist with breathing and spinal movement. Twelve tiny triangle muscles make up the levatores costarum, which connect the thoracic vertebrae to the nearby ribs. They extend from C7 to T12 levels in the thoracic area and are…
Introduction The pronator quadratus is a quadrangular, thin, short, and flat muscle located in the anterior compartment of the forearm. It is a member of the deep group of forearm flexors, together with flexor digitorum profundus and pollicis longus. The superficial group of forearm flexors overlays these three muscles. The pronator quadratus connects the distal…
