General information
The pain on the outer upper arm is an unpleasant sensory sensation that can develop for various reasons. Soft tissue such as muscles and bursae as well as nerves and bones can be damaged and thus responsible for the pain. Depending on the cause, the pain character varies between stabbing, pulling or dull.
Often, pain radiates into the outer upper arm from the shoulder. In addition, the pain can occur selectively or over a wide area. The localization of the pain on the outer upper arm is characteristic for some injury patterns or diseases, which will be explained in more detail below.
Causes
The causes responsible for pain in the upper arm are very diverse. Different structures can also be affected: Muscular injuries (med. : lesions) are mostly sore muscles, tension or torn muscle fibers.
The deltoid muscle (lat. : deltoid muscle) is the most relevant muscle on the outside of the upper arm. In general, muscles directly on the upper arm can be affected, as well as muscles of the rotator cuff, i.e. the shoulder joint, which can lead to pain radiating into the outer upper arm.
Myositis, i.e. inflammation of the muscles, is a rare cause of muscular pain. If the pain emanates from nerve structures, it is either caused by inflammation of certain nerves, i.e. neuritis, or, for example, by a viral disease pattern, shingles, which develops in relation to dermatomas. Nerve pain is characteristically felt by those affected as stabbing or stab-like.
Nerves that run along the upper arm and can be affected are for example the radial and axillary nerves. Furthermore, inflamed bursae of the shoulder joint can be responsible for the pain in the outer upper arm. Due to the anatomical proximity to certain muscles of the upper arm, such as the deltoid muscle, the pain can be transmitted via the muscle.
In addition, the deltoid muscle itself can be the pain trigger due to a space requirement caused by the swelling of the inflamed bursa, as it is compressed and constricted. Finally, bony injuries can also be the cause of pain in the upper arm. Here, the fracture of the upper arm after a fall is worth mentioning as the best example.
- Muscles,
- Nerves,
- Bursa sacs
- Or bones.
Pain in the outer upper arm can be caused by inflamed bursae in the shoulder. There are four larger relevant bursae in the shoulder. They function to cushion the surrounding muscles, tendons and nerves and to buffer them against the pressure or frictional forces that occur during exercise.
Buffering is possible because the bursae are filled with synovial fluid. If the shoulder is subjected to very strong and long-lasting mechanical stress, these bursae can become inflamed. The inflammation is associated with severe pain in the shoulder itself, but also in the upper arm.
As part of the inflammatory reaction, the bursae swell in addition to the pain by increasing the amount of synovial fluid they contain, so that they can constrict surrounding muscles or nerves. Since muscles run or originate in this area that also extend to the upper arm, the pain can extend along these structures to the outer upper arm. This explains the radiating character of the pain.
The deltoid muscle (lat. Musculus deltoideus) serves as the best example here. It originates at various points in the area of the shoulder joint and attaches to a roughened bone structure, the tuberosity deltoidea humeri (“tuberositas” = bone projection with roughened structure; “humerus” = humeral bone).
The deltoid muscle runs directly over one of the external bursae. This spatial proximity is responsible, for example, for the transmission or transmission of pain to the upper arm. The triceps is a muscle with functional effects on the shoulder and elbow joints.
Tensioning the muscle causes adduction, i.e. pulling the upper arm towards the trunk and stretching the elbow joint. The triceps runs along the back of the upper arm from the shoulder to the elbow. In addition to the biceps on the front of the upper arm, it is one of the major muscles of the upper arm.Due to its anatomical position and size, damage with pain in the upper arm can also manifest itself on the posterior outer side.
A sore muscle can be a harmless reason for the pain. In this case, the triceps has several tiny tears in the muscle fibers. In more serious cases, however, there may be tears or tears in the area of the triceps’ tendons.
This pain is perceived by those affected as being much more intense than pure muscle ache. Depending on the severity of the tear, there may be swelling due to slipping of the muscle abdomen and bruising. The term rotator cuff refers to four muscles of the deep shoulder muscles.
These are the: They all originate from bony structures in the area of the shoulder joint and have their attachment at the large and small bony cusps, tuberculum majus and tuberculum minus, of the humerus. The deep muscles of the rotator cuff surround the shoulder joint and therefore fulfill the task of holding the joint in position. If the rotator cuff is injured by falls, overloading or inflammation, the pain can radiate along the muscles to the upper arm.
Here again, the muscle attachments on the outside of the upper arm are responsible for the transmission of the pain. In addition to the pain, the shoulder joint may be restricted or become unstable, especially during movement.
- M.
infraspinatus,
- M. supraspinatus,
- M. subscapularis
- And M. teres minor.
Pain can also be caused by an inflammation of the nerves (Latin: neuritis).
Depending on which nerves in the shoulder and arm area are affected, the pain can be projected onto the outer upper arm. In general, the pain caused by an inflammation of the nerves is much more intense and stronger than pain due to muscular damage. Affected persons describe the pain in the upper arm as pulling along the nerves.
In the case of nerve inflammation, however, not only the inflamed nerve itself hurts, but possibly also the surrounding muscles supplied by the nerve. In addition, the pain in the upper arm is often accompanied by a tingling sensation on the outside. Because the pain is so intense, sufferers are very limited in their everyday mobility; especially when moving overhead, for example when putting on tops or combing their hair.
Reasons for an inflammation of the nerves in the area of the outer upper arm can be incorrect or excessive strain, strong mechanical irritation or entrapment. Especially the shoulder area in the transition to the upper arm is a frequent manifestation site of nerve inflammation. Nerves such as the axillary and radial nerve run through the nerve bundle in the shoulder and axilla region and then move to the outer and back of the upper arm.
This nerve bundle, brachial plexus, can be pinched by certain postures. An inflammation of the nerves running in it can then be the result. In this case one speaks of a thoracic outlet syndrome.
Puncture-like pain on the outside of the upper arm can be considered a typical first sign of shingles. This is the skin manifestation of a viral disease with the Varicella Zoster Virus (VZV), the trigger of chickenpox. In the beginning, in addition to the stab-like pain, symptoms such as fatigue and fever occur.
A few days later, the characteristic skin rash with blistering, which is called shingles, develops. This rash always manifests itself along a circumscribed area of skin that is supplied by the affected nerve. The affected area also shows an increased sensation of pain.
Even otherwise painless touches are perceived as painful. This is also called allodynia. A fall on the arm is usually absorbed by the impact of the elbow or shoulder.
Nevertheless, the outside of the upper arm can also be affected by such a fall. Subsequent pain can develop due to injuries to the upper arm bone, muscles or nerves. It is also possible for pain to radiate from an injury to the shoulder.
Such an injury could be damage to one or more muscles of the rotator cuff or bony injuries. Various clinical tests can be used to test the functionality of individual muscles. In this way, conclusions can be drawn as to whether, for example, muscles were torn or completely torn during the fall.If pain on the outer upper arm can be triggered particularly intensively at a single point, this can be an indication of a contusion.
In any case, bruising and swelling of the upper arm can occur in addition to the pain. Furthermore, the humerus can break if the patient falls. This is accompanied by severe pain and possibly certain fracture signs such as unnatural mobility, visible pieces of bone in the case of an open fracture and crepitations, i.e. rubbing noises of the bones. Pain after a fall on the outer upper arm requires precise diagnosis due to the large number of causes.
