Don’t kid yourself; tears and strains of the deltoid muscle are hardly the only causes of pain in this area. You can also count in different cancers and heart problems.

However, usually, pain in the deltoid is usually of a muscular origin: either a strain of the fibers or a tearing to some degree (minor, moderate, severe).

“The deltoid muscle is divided into three parts; the posterior, medial and anterior deltoid (back, middle and front),” says Dr. Tom Carpenter, corrective exercise specialist, certified personal trainer and chiropractor, inventor of Stand Corrected™, a portable harness-like stretching tool that helps alleviate back, neck and shoulder pain.

Grade I, II and III tears to the deltoid muscle are common.

However, another common cause of deltoid muscle pain is a rotator cuff injury, which includes impingement syndrome.

“The arm drop test is one way to check for this,” says Dr. Carpenter.

“Other issues that might cause pain in the deltoid area are arthritis, ligament injury, tendonitis, fracture, referred pain from the cervical spine [from a pinched nerve], etc.,” says Dr. Carpenter.

“Does it hurt performing bent over barbell rows, butterflies, or upright rows and front arm raises?

“This will help to isolate which part of the deltoid is involved and possibly strained.

“Or it could be the result of something called altered cross joint coupling, as a result of synergistic dominance (helper muscles acting as prime movers due to poor technique during exercise).

“In other words, the muscles aren’t transferring forces across the shoulder joint properly because of poor form, so they start to hurt.”

Let’s not forget about bursitis and trauma (which can cause multiple issues leading to shoulder pain).

And there’s a slew of more serious causes, but let’s first take a look at the worst: cancers and heart problems.

Cancer & Heart Problems:
Can Cause Pain in the Deltoid Muscle Region

These conditions, however, don’t actually damage the muscle fibers or joint itself.

Pancoast tumor. A type of lung cancer, the mass can encroach upon the brachial plexus nerves which are in close proximity to the shoulder – hence, shoulder pain.

Osteosarcoma and chondrosarcoma. These are bone cancers.

Breast cancer metastasis. Breast cancer can spread to the upper arm bone and cause shoulder pain in the deltoid region, masquerading as a rotator cuff problem.

Angina. This is chest pain that results from inadequate blood flow in the coronary arteries. The pain can radiate to the shoulder.

Heart Attack. An imminent or heart attack in progress can cause shoulder pain, and not necessarily chest pain or heaviness or shortness of breath.

Other Serious Causes of Pain
in the Deltoid Muscle Area

• Avascular necrosis (loss of blood to a bone caused by joint or bone trauma or fatty deposits in blood vessels).

• Hiatal hernia (a portion of the stomach slides up into the chest cavity)

• Septic arthritis (infection)

Additional though Less Serious Causes of
Pain in the Deltoid Muscle Region

• Osteoarthritis (wearing down of cartilage)
• Polymyalgia rheumatica (inflammatory disorder)

In summary, the causes of pain located in the deltoid muscle or near it don’t always involve an injury or strain to the fibers themselves — but far more often than not, they do.

dr. carpenter

Photo credit: Aleesia Forni

Used daily and over time, the Stand Corrected™ stretching tool can reverse back damage caused by years of poor posture.