3 Common Reasons Why You're Feeling Arm Pain and Weakness

Arm and shoulder weakness and pain can make simple daily tasks difficult. Many conditions can cause these symptoms, including muscle or tendon injury and arthritis.

The shoulder is a complicated joint formed by three bones and multiple muscles and tendons that work together to give the arm its exceptional mobility. Overuse, injuries and arthritic conditions can damage the shoulder, causing pain that often extends into the upper arm.

Loss of shoulder mobility and pain commonly give rise to weakness in the shoulder and upper arm. Treatment for shoulder conditions focuses on maintaining or restoring joint function and alleviating pain.

Read more: How to Treat a Sore Shoulder

Biceps Tendon Tear

The biceps brachii, commonly known as the biceps muscle, stretches from the shoulder to the elbow on the front of the arm. The biceps brings the forearm toward the shoulder with elbow bending. Injury or chronic overuse of the biceps can cause partial or complete tearing of the upper biceps tendons, which attach the muscle to the bones of the shoulder.

Symptoms associated with a biceps tendon tear include pain and tenderness in the front of the shoulder and upper arm, biceps cramps and bulging, upper arm bruising, and elbow and shoulder weakness 1.

A biceps tendon tear often heals with rest and physical therapy, although the muscle may be weaker than it was before the injury. People who require full biceps strength may require surgical tendon repair followed by physical therapy.

Shoulder Impingement Syndrome

The shoulder has the most extensive range of motion of any joint in the body. Injury or overuse of the shoulder can lead to inflammation of the tendons and bursae, which are gel-filled sacs that reduce friction between the muscles, bones and tendons as they slide over one another with arm movement. Swelling due to inflammation can crowd the small area at the top of the shoulder through which the muscles and tendons move.

The bones of the shoulder may rub against the muscles at the top of the shoulder, limiting movement. This condition is known as shoulder impingement, which causes pain that often radiates down the upper arm. Raising the affected arm overhead provokes pain. Over time, the upper arm becomes weak.

Treatment for shoulder impingement typically begins with rest and anti-inflammatory medication, such as ibuprofen. Physical therapy leads to substantial improvement for most people. Those who continue to have pain after initial treatment may require surgery.

Shoulder Arthritic Conditions

The shoulder joint is susceptible to arthritic conditions, including osteoarthritis and rheumatoid arthritis 3. These conditions slowly degrade the shoulder joint, causing loss of joint mobility, stiffness, grinding or popping when the joint is in use, and aching pain that often radiates down the upper arm. With loss of shoulder function, the arm becomes progressively weaker due to lack of use.

Anti-inflammatory medication and physical therapy can control symptoms and disease progression in some patients. In severe cases, the shoulder joint may be replaced to alleviate pain and restore mobility.

Seek Medical Care

Visit your doctor if you experience shoulder and arm pain, especially if weakness is also present. Early diagnosis and treatment help to improve the chances that you can regain full function of your arm and shoulder. Your doctor will also check to be sure there isn't another underlying medical condition contributing to your symptoms.

Read more: Shoulder Pain