Muscles of the Arm

muscles of the arm

Several muscles in the arm work together to make the arm bend and straighten. These muscles are known as extensors. When they contract, they form bulges on the surface. You can identify them by their appearance. The Supinator, Extensor indicis, Coracobrachialis, Brachialis, and Tensor digitorum longus are all involved in arm movement.


The supinator muscles are located in the posterior compartment of the forearm. The proximal part of the supinator is connected to the ulna. Supination of the forearm involves rotation of the radius laterally. Pronation, on the other hand, involves rotation of the radius medially. This article will discuss the differences between supination and pronation. Using the supinator is beneficial for both supine and pronate movements.

Extensor indicis

The Extensor indicis is one of the three main muscles in the arm, located between the thumb and the forefinger. It is derived from the interosseous membrane, attached to the hood of the index finger. It is innervated by the posterior interosseous branch. Injuries to this muscle may cause pain, wrist drop, and other symptoms. Its abnormal origin can also cause weak index finger extension.


Injuries to the brachialis muscle can be painful and limiting to your activity. Physical therapy is often the first option. A sling or splint may be recommended while healing. Electrical stimulation can be used to reduce pain caused by a brachialis injury. MRIs can also help evaluate soft tissues in the anterior elbow. Physical therapy for brachialis muscle injury may involve ice therapy, compression, or a combination of both.


The coracobrachialis muscle originates from the musculocutaneous nerve and is split into two heads. The superficial head arises from the coracoid process of the scapula, while the deep head originates from the lateral side of the short head of biceps brachii. The two heads attach to the tendon near the common point of insertion. The musculocutaneous nerve passes between the superficial and deep heads.

Interosseous muscles

We investigated the length of the interosseous muscles of the arm using the cadaver method. We measured the PCSA, TCSA, and Lt/Lfopt of the first dorsal interosseous. These parameters were found to vary significantly in relation to one another and between the different heads of the FDI. These data were analyzed using a paired t-test to determine whether there was a significant difference in the length of the muscles between the two heads.


Abductors of the arm perform the motion of lifting the arm away from the body. The abduction occurs in the sagittal plane, with the arm parallel to the body at the beginning and perpendicular to the body at the end. The arm is then lifted above the shoulder joint so that the humerus is pointing upwards. The muscles that perform abduction are the trapezius, supraspinatus, deltoid, and serratus anterior.

Forearm flexors

Forearm flexors are the muscles in the forearm that allow the forearm to bend. The forearm flexors play a vital role in actions that require complex muscle firing orders. They are also involved in the synchronization of hand and wrist movements, such as pinching a quartzite crystal on a rock face. To exercise these muscles, you should perform grip exercises and hold the positions of your elbow and wrist.

Forearm pronator

The forearm flexors control wrist flexion. They originate above the elbow. The forearm pronator muscles rotate the forearm palm-down. They are attached to the Ulnar collateral ligament, a much deeper tissue in the same general area. These ligaments prevent the elbow joint from fully opening. If one of these muscles is injured, rehabilitation and surgery must take into account the forces involved.


The extensor pollicis longus, or EPL, is a group of three muscles in the arm. They run from the humerus to the phalanges and metacarpals, and are antagonists of flexor muscles. The EPL is weaker than the flexors, but allows a person to open and close the hand without using a joint. The long EPL is responsible for the movement of the thumb.

Love it? Why not sharing?