The ones that originate on the axial skeleton are the pectoralis major and the latissimus dorsi. The deltoid, subscapularis, supraspinatus, infraspinatus, teres major, teres minor, and coracobrachialis originate on the scapula.
The pronators are the pronator teres and the pronator quadratus. The supinator is the only one that turns the forearm anteriorly. The extrinsic muscles of the hands originate along the forearm and insert into the hand in order to facilitate crude movements of the wrists, hands, and fingers. The superficial anterior compartment of the forearm produces flexion. These muscles are the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and the flexor digitorum superficialis. The deep anterior compartment produces flexion as well.
The rest of the compartments produce extension. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris are the muscles found in the superficial posterior compartment.
The deep posterior compartment includes the abductor longus, extensor pollicis brevis, extensor pollicis longus, and the extensor indicis. Finally, the intrinsic muscles of the hands allow our fingers to make precise movements, such as typing and writing. They both originate and insert within the hand.
The thenar muscles, which are located on the lateral part of the palm, are the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and adductor pollicis.
The hypothenar muscles, which are located on the medial part of the palm, are the abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi. The intermediate muscles, located in the middle of the palm, are the lumbricals, palmar interossei, and dorsal interossei. The tendons of which muscles form the rotator cuff?
Why is the rotator cuff important? Tendons of the infraspinatus, supraspinatus, teres minor, and the subscapularis form the rotator cuff, which forms a foundation on which the arms and shoulders can be stabilized and move. List the general muscle groups of the shoulders and upper limbs as well as their subgroups. The muscles that make up the shoulders and upper limbs include the muscles that position the pelvic girdle, the muscles that move the humerus, the muscles that move the forearm, and the muscles that move the wrists, hands, and fingers.
Skip to content The Muscular System. Learning Objectives By the end of this section, you will be able to: Identify the muscles of the pectoral girdle and upper limbs Identify the movement and function of the pectoral girdle and upper limbs. Muscles That Position the Pectoral Girdle Muscles that position the pectoral girdle are located either on the anterior thorax or on the posterior thorax Figure and Figure.
Muscles That Position the Pectoral Girdle. The muscles that stabilize the pectoral girdle make it a steady base on which other muscles can move the arm. Note that the pectoralis major and deltoid, which move the humerus, are cut here to show the deeper positioning muscles.
Muscles That Move the Humerus Similar to the muscles that position the pectoral girdle, muscles that cross the shoulder joint and move the humerus bone of the arm include both axial and scapular muscles Figure and Figure.
Biceps brachii is the primary flexor of the forearm; it also supinates the forearm and weakly flexes the arm at the shoulder. Coracobrachialis muscle, together with the short head of biceps brachii muscle, originates from the tip of the coracoid process.
It inserts on to the middle third of the medial surface and border of the humerus. Coracobrachialis weakly adducts the arm and aids in stabilizing the humerus. Triceps brachii muscle has three heads. Each contains many more muscles than described below due to the requirement for more complex movements in the wrist and hand. The anterior compartment of the forearm is split into superficial, intermediate, and deep layers. These muscles are generally responsible for flexing of the wrist and fingers and pronation of the forearm.
The posterior compartment of the forearm is split into superficial and deep regions. The muscles are generally responsible for extension of the wrist and fingers. The extrinsic muscles of the hand are responsible for the larger scale, stronger movements of the wrist and hand.
The intrinsic muscles produce finer, more controlled movements and play important roles in maintaining grip. The thenar muscles are three short muscles located at the base of the thumb and responsible for its fine movement. The hypothenar muscles are located at the base of the little finger. Their naming, function, and organization are similar to those of the thenar muscles.
Muscles of the shoulder include those that attach to the bones of the shoulder to move and stabilize the joint. The shoulder or glenohumeral joint is a ball and socket joint formed between the humerus and scapula. Due to the shallowness of the socket and relatively loose connections, the shoulder joint allows for a wide range of motion; however, this wide range makes the joint unstable and thus more prone to dislocation and injury than other joints.
Two other joints make up the shoulder; the acromioclavicular joint of the clavicle and scapula, which allows the arm to be raised above the head, and the sternoclavicular joint of the clavicle and sternum, which plays an important role in facilitating movement of the upper arm and connecting it to the rest of the skeleton. Muscles that act on the shoulder can be classified as extrinsic, intrinsic, pectoral, or upper arm.
Upper arm muscles will be discussed in a later section since they primarily promote forearm movement. Extrinsic muscles of the shoulder originate from the trunk and attach to the bones of the shoulder. They can be further subdivided into superficial and deep layers. Location of the trapezius muscle : Highlighted in orange, the trapezius is a large, broad muscle of the back that acts on the shoulder.
As suggested by the name, superficial muscles lie on the surface. There are two superficial extrinsic muscles. Location of the deltoid muscles : Highlighted in orange, the deltoids cover the rounding of the shoulder joint. Intrinsic muscles originate from the scapula or clavicle and attach to the humerus. There are six intrinsic muscles, four of which form the rotator cuff. The rotator cuff is a group of four muscles that pull the ball of the humerus into the shallow socket of the scapula, adding required stability.
The rotator cuff complex is composed of the supraspinatus, infraspinatus, subscapularis, and teres minor all of which originate from the scapula and connect to the humerus. The supraspinatus is involved in abduction of the arm in association with the deltoid, while the other muscles facilitate rotation of the arm. Muscles of the rotator cuff : Muscles of the rotator cuff and presented with the triceps brachii.
Pectoral muscles lie in the chest and exert force through the shoulder to move the upper arm. Three pectoral muscles interact with the shoulder.
Privacy Policy. Skip to main content. Exercise Science. Muscles That Move the Arm. Filter By Category. View All Categories. Here, we will look at the muscles that move the arm at the shoulder, elbow, and wrist joints. Shoulder Joint The glenohumeral joint—commonly referred to as the shoulder joint—consists of the attachment of the humerus bone to the scapula. Subscapularis Latissimus dorsi and pectoralis major External shoulder rotation From a position of internal shoulder rotation, rotate your arm so that the elbow faces backward.
Infraspinatus and teres minor Horizontal abduction For the start postion, lift your arms in front of you. Latissimus dorsi and posterior fibers of deltoid Horizontal adduction From the starting position, lift your arms out to the side.
The actions occurs as you then move your arms in front of you Pectoralis major and anterior fibers of deltoid Elbow and Wrist Joints The elbow joint consists of the humerus, radius and ulna bones. Action of the Elbow and Wrist What the Action Looks Like Try It Yourself Primary Muscles Elbow flexion Bend your elbow Biceps brachii Elbow extension Straighten your elbow Triceps brachii Wrist flexion Bend your palm toward your forearm Wrist flexors Wrist extension Bend the back of your hand toward your forearm Wrist extensors A helpful way to learn anatomy is to move and mimic the actions for the muscles you are learning that week.
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