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Supraspinatus
The supraspinatus (: supraspinati) is a relatively small muscle of the upper back that runs from the supraspinous fossa superior portion of the scapula (shoulder blade) to the greater tubercle of the humerus. It is one of the four rotator cuff muscles and also abducts the arm at the shoulder. The spine of the scapula separates the supraspinatus muscle from the infraspinatus muscle, which originates below the spine. Structure Origin The supraspinatus muscle arises from the medial two-thirds supraspinous fossa of the scapula. Insertion The supraspinatus tendon inserts onto the superior facet of the greater tubercle of the humerus. Relations The supraspinatus muscle tendon passes laterally beneath the cover of the acromion. The tendon blends with the shoulder joint capsule. Nerve supply The supraspinatus muscle is innervated by suprascapular nerve (C5-6) of the upper trunk of the brachial plexus. Function The supraspinatus muscle performs abduction of the arm, and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoulder
The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The shoulder joint, also known as the glenohumeral joint, is the major joint of the shoulder, but can more broadly include the acromioclavicular joint. In human anatomy, the shoulder joint comprises the part of the body where the humerus attaches to the scapula, and the head sits in the glenoid cavity. The shoulder is the group of structures in the region of the joint. The shoulder joint is the main joint of the shoulder. It is a ball and socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body. The joint capsule is a soft tissue envelope that encircles the glenohumeral joint and attaches to the scapula, humerus, and head of the biceps. It is lined by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotator Cuff
The rotator cuff (SITS muscles) is a group of muscles and their tendons that act to stabilize the human shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are: * supraspinatus muscle * infraspinatus muscle * teres minor muscle * subscapularis muscle. Structure Muscles composing rotator cuff The supraspinatus muscle spreads out in a horizontal band to insert on the superior facet of the greater tubercle of the humerus. The greater tubercle projects as the most Lateral (anatomy), lateral structure of the humeral head. Medial (anatomy), Medial to this, in turn, is the lesser tubercle of the humeral head. The subscapularis muscle Origin (anatomy), origin is divided from the remainder of the rotator cuff origins as it is deep to the scapula. The four tendons of these muscles converge to form the rotator cuff tendon. These tendinous Insertion (anatomy), insertions along with the articular cap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoulder Impingement Syndrome
Shoulder impingement syndrome is a syndrome involving tendonitis (inflammation of tendons) of the rotator cuff muscles as they pass through the subacromial space, the passage beneath the acromion. It is particularly associated with tendonitis of the supraspinatus muscle. This can result in pain, weakness, and loss of movement at the shoulder. Signs and symptoms The most common symptoms in impingement syndrome are pain, weakness and a loss of movement at the affected shoulder. The pain is often worsened by shoulder overhead movement and may occur at night, especially when lying on the affected shoulder. The onset of the pain may be acute if due to an injury or insidious if due to a gradual process such as an Osteoarthritis, osteoarthritic Bone spur, spur. The pain has been described as dull rather than sharp, and lingers for long periods of time, making it hard to fall asleep. Other symptoms can include a grinding or popping sensation during movement of the shoulder. The range of mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprascapular Nerve
The suprascapular nerve is a mixed (sensory and motor) nerve that branches from the upper trunk of the brachial plexus. It is derived from the ventral rami of cervical nerves C5-C6. It provides motor innervation to the supraspinatus muscle, and the infraspinatus muscle. Structure Origin The suprascapular nerve arises from the upper trunk of the brachial plexus which is formed by the union of the ventral rami of the cervical nerves C5-C6. Course and relations After branching from the upper trunk, the nerve passes across the posterior triangle of the neck parallel to the inferior belly of the omohyoid muscle and deep to the trapezius muscle. It then runs along the superior border of the scapula through the suprascapular canal, in which it enters via the suprascapular notch inferior to the superior transverse scapular ligament and enters the supraspinous fossa. It then passes beneath the supraspinatus and curves around the lateral border of the spine of the scapula through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humerus
The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extremity of humerus, upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities). The body of humerus, body is cylindrical in its upper portion, and more prism (geometry), prismatic below. The lower extremity of humerus, lower extremity consists of 2 epicondyles, 2 processes (trochlea of the humerus, trochlea and capitulum of the humerus, capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its Surgical neck of the humerus, surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons. Etymology The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraspinatus Muscle
In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.''Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspinatus is to externally rotate the humerus and stabilize the shoulder joint. Structure It attaches medially to the infraspinous fossa of the scapula and laterally to the middle facet of the greater tubercle of the humerus. The muscle arises by fleshy fibers from the medial two-thirds of the infraspinatous fossa, and by tendinous fibers from the ridges on its surface; it also arises from the infraspinatous fascia which covers it, and separates it from the teres major and teres minor. The fibers converge to a tendon, which glides over the lateral border of the spine of the scapula and passing across the posterior part of the capsule of the shoulder-joint, is inserted into the middle impression on the greater tubercle of the humerus. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supraspinous Fossa
The supraspinous fossa (supraspinatus fossa, supraspinatous fossa) of the posterior aspect of the scapula (the shoulder blade) is smaller than the infraspinous fossa, concave, smooth, and broader at its vertebral than at its humeral end. Its medial two-thirds give origin to the Supraspinatus. Structure The fossa can be exposed by the removal of skin and the superficial fascia of the back and the trapezius muscle. The supraspinous fossa is bounded by the spine of scapula on the inferior side, acromion process on the lateral side and the superior angle of scapula on the superior side. Supraspinatus muscle originates from the supraspinous fossa. Distal attachment of the levator scapulae muscle is also on the medial aspect of the fossa. Function The suprascapular artery and nerve are found within the fossa. The posterior branch of the suprascapular artery supplies the supraspinatous muscle. Dorsal scapular artery also gives off a collateral branch and anastomoses with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glenoid Cavity
The glenoid fossa of the scapula or the glenoid cavity is a bone part of the shoulder. The word ''glenoid'' is pronounced or (both are common) and is from , "socket", reflecting the shoulder joint's ball-and-socket form. It is a shallow, pyriform articular surface, which is located on the lateral angle of the scapula. It is directed laterally and forward and articulates with the head of the humerus; it is broader below than above and its vertical diameter is the longest. This cavity forms the glenohumeral joint along with the humerus. This type of joint is classified as a synovial, ball and socket joint. The humerus is held in place within the glenoid cavity by means of the long head of the biceps tendon. This tendon originates on the superior margin of the glenoid cavity and loops over the shoulder, bracing humerus against the cavity. The rotator cuff also reinforces this joint more specifically with the supraspinatus tendon to hold the head of the humerus in the glenoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Tubercle
The greater tubercle of the humerus is the outward part the upper end of that bone, adjacent to the large rounded prominence of the humerus head. It provides attachment points for the supraspinatus, infraspinatus, and teres minor muscles, three of the four muscles of the rotator cuff, a muscle group that stabilizes the shoulder joint. In doing so the tubercle acts as a location for the transfer of forces from the rotator cuff muscles to the humerus. Structure The upper surface of the greater tubercle is rounded, and marked by three flat impressions: * the highest ("superior facet") gives insertion to the supraspinatus muscle. * the middle ("middle facet") gives insertion to the infraspinatus muscle. * the lowest ("inferior facet"), and the body of the bone for about 2.5 cm, gives insertion to the teres minor muscle. The lateral surface of the greater tubercle is convex, rough, and continuous with the lateral surface of the body of the humerus. It can be describ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supraspinous Fossa
The supraspinous fossa (supraspinatus fossa, supraspinatous fossa) of the posterior aspect of the scapula (the shoulder blade) is smaller than the infraspinous fossa, concave, smooth, and broader at its vertebral than at its humeral end. Its medial two-thirds give origin to the Supraspinatus. Structure The fossa can be exposed by the removal of skin and the superficial fascia of the back and the trapezius muscle. The supraspinous fossa is bounded by the spine of scapula on the inferior side, acromion process on the lateral side and the superior angle of scapula on the superior side. Supraspinatus muscle originates from the supraspinous fossa. Distal attachment of the levator scapulae muscle is also on the medial aspect of the fossa. Function The suprascapular artery and nerve are found within the fossa. The posterior branch of the suprascapular artery supplies the supraspinatous muscle. Dorsal scapular artery also gives off a collateral branch and anastomoses with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
