Symptoms A-Z

Shoulder Weakness Symptoms, Causes & Common Questions

Understand shoulder weakness symptoms, including 5 causes & common questions.

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5 Possible Shoulder Weakness Causes

The list below shows results from the use of our quiz by Buoy users who experienced shoulder weakness. This list does not constitute medical advice and may not accurately represent what you have.

Brachial plexopathy (shoulder nerve issue)

The brachial plexus is a web of nerves between the neck and shoulder, connecting the spinal cord nerves to the arm. There is one web on each side of the neck. Any injury that forces the shoulder to stretch down, and the neck to stretch up and away, can damage these nerves and cause brachial plexopathy.

Sports injuries and car accidents are often involved. Inflammation, tumors, and radiation treatment can also damage the brachial plexus.

Milder symptoms include numbness and weakness in the arm, with a shocklike stinging or burning sensation. A more severe injury can cause paralysis and loss of feeling in the arm, with pain in some parts of the arm, hand, and shoulder.

These symptoms should be seen by a medical provider since permanent damage can result if the injuries are not treated.

Diagnosis is made through electromyography (EMG) testing, CT scan, MRI, and sometimes angiogram.

Treatment usually involves rest and physical therapy. Surgery may be necessary to remove scar tissue or repair the damaged nerves.

Rarity: Uncommon

Top Symptoms: pain in one arm, shoulder pain that shoots to the arm, arm weakness, numbness in one arm, shoulder pain

Symptoms that never occur with brachial plexopathy (shoulder nerve issue): pain in the front middle part of the neck

Urgency: Primary care doctor

Limb-girdle muscular dystrophy

Limb-girdle muscular dystrophy is an inherited disorder that involves varying muscle weakness and wasting.

Rarity: Ultra rare

Top Symptoms: muscle aches, weakness, arm weakness, leg weakness, shoulder weakness

Symptoms that always occur with limb-girdle muscular dystrophy: weakness

Urgency: Primary care doctor

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Repetitive strain injury of the shoulder ("swimmer's shoulder")

Repetitive strain injury of the shoulder is caused by consistent repetitive use.

Rarity: Uncommon

Top Symptoms: shoulder pain from overuse, shoulder weakness, shoulder numbness

Symptoms that always occur with repetitive strain injury of the shoulder ("swimmer's shoulder"): shoulder pain from overuse

Symptoms that never occur with repetitive strain injury of the shoulder ("swimmer's shoulder"): severe shoulder pain, shoulder injury

Urgency: Self-treatment

Biceps tendon rupture

The biceps muscle in the upper arm is anchored at the top by two separate tendons. One connects to the shoulder blade and one connects to the top of the shoulder joint. If one of these tendons is strained enough to completely tear it in two, this is called a rupture.

The injury is most common in people over age 40, especially after years of overuse of the shoulder. The person may have had episodes of biceps tendinitis in the past, which is a sign of fraying and damage to the tendon. In younger people it is primarily an acute sports injury, from weightlifting or from falling.

Symptoms include a pop or snap at the top of the shoulder, with sharp pain. There may soon be bruising halfway down the upper arm with obvious "balling up" of the partially disconnected muscle.

Diagnosis is made through patient history, physical examination, x-rays, and sometimes MRI.

Treatment involves over-the-counter anti-inflammatory medication; rest; ice; and physical therapy. Surgery may be done in some cases.

Rarity: Uncommon

Top Symptoms: pain in one shoulder, pain in the front of the shoulder, spontaneous shoulder pain, dull, achy shoulder pain, shoulder pain that gets worse at night

Symptoms that always occur with biceps tendon rupture: pain in the front of the shoulder, pain in one shoulder

Urgency: Primary care doctor

Rotator cuff tear

The rotator cuff is a group of muscles and tendons that surround the shoulder joint, keeping the head of the upper arm bone firmly within the shallow socket of the shoulder. A rotator cuff injury (tear) can cause a dull ache in the shoulder, which often worsens when sleeping on the involved side.

Rarity: Common

Top Symptoms: pain in one shoulder, dull, achy shoulder pain, difficulty moving the shoulder, pain in the outside of the shoulder

Symptoms that always occur with rotator cuff tear: shoulder pain from an injury, pain in one shoulder, shoulder pain from overuse

Urgency: Primary care doctor

Questions Your Doctor May Ask About Shoulder Weakness

To diagnose this condition, your doctor would likely ask the following questions:

  • Have any of your muscles gotten much smaller (wasted away)?
  • Does your pain continue into the night?
  • Have someone push down on your arm as you hold it out. Can you resist? (This is known as the axillary nerve test.)
  • How would you explain the cause of your shoulder pain?

The above questions are also covered by our A.I. Health Assistant.

If you've answered yes to one or more of these questions

Take a quiz to find out what might be causing your shoulder weakness

Shoulder Weakness Symptom Checker Statistics

People who have experienced shoulder weakness have also experienced:

  • 15% Pain In One Shoulder
  • 13% Upper Arm Weakness
  • 9% Hand Weakness

People who have experienced shoulder weakness were most often matched with:

  • 42% Brachial Plexopathy (Shoulder Nerve Issue)
  • 42% Limb-Girdle Muscular Dystrophy
  • 14% Repetitive Strain Injury Of The Shoulder ("Swimmer'S Shoulder")

People who have experienced shoulder weakness had symptoms persist for:

  • 45% Over a month
  • 17% Less than a week
  • 16% Less than a day

Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

Shoulder Weakness Symptom Checker

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Disclaimer: The article does not replace an evaluation by a physician. Information on this page is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes.