Outer Shoulder Pain? These Muscles Could be to Blame

Jackson, a 38-year-old car mechanic, had spent over a decade working long hours underneath vehicles, constantly reaching, lifting, and maneuvering heavy tools. Lately, he had been experiencing nagging pain in his outer shoulder, which worsened by the end of his shifts. At first, he dismissed it as just part of the job, but when the pain began radiating down his arm and making it difficult to work, he knew he had to find a solution.

After doing some research, Jackson visited a massage therapist who specialized in muscular pain and movement dysfunction. The therapist found multiple tight and overused muscles in his neck and shoulders, particularly in the rotator cuff muscles. Through targeted massage therapy, these muscles were released, improving Jackson’s range of motion and reducing his pain. The therapist also worked on opening Jackson's chest to help balance the upper body.

Jackson also began incorporating corrective exercises into his routine. These exercises helped strengthen his chest and the front of his shoulders, helping to bring balance to the muscles in his upper body. Within a few weeks, he noticed significant improvement—his pain had decreased, and he felt stronger and more stable at work. By maintaining a combination of regular massage therapy and corrective exercises, Jackson was able to stay pain-free and continue his demanding job without discomfort.

How Overused Muscles can cause Outer Shoulder Pain

When a muscle is overused—kept in a tight or constricted state for too long—it becomes fatigued and tense, much like you might feel after a stressful, overbooked week. Over time, the muscle can lock into this tight position, forming painful knots known as trigger points. These knots don’t just cause localized pain; they can pull on surrounding muscles, restrict movement, and even contribute to joint dysfunction.

In cases of outer shoulder pain, overused muscles in the neck and shoulder can develop trigger points, leading to discomfort, numbness, and weakness. This may result from a sudden overload event—such as lifting or carrying more weight than your body could handle—causing a traumatic strain. However, more often, shoulder pain stems from prolonged overuse, especially when the arms are not well supported or are in constant motion. Whether you spend your days working at a desk, as a mechanic, hairstylist, dentist, or construction worker, repetitive motions and sustained positions can gradually lead to muscle fatigue and dysfunction, increasing the likelihood of chronic shoulder issues of all kinds.

My exploration into how overused and triggered muscles impact daily life has been deeply influenced by Myofascial Pain and Dysfunction: The Trigger Point Therapy Manual by Dr. Janet G. Travell and Dr. David G. Simons. This comprehensive two-volume set transformed my approach to massage, allowing me to provide lasting relief to my clients. For a more accessible, hands-on resource, I highly recommend The Trigger Point Therapy Workbook by Clair Davies, NCTMB, which breaks down these concepts into a practical, easy-to-follow guide for self-treatment.

Muscles that can create Outer Shoulder Pain

Now that we've explored how muscles can contribute to or even cause pain in the outer shoulder, let's take a closer look at the specific muscles that may be responsible. While there's much more to say about each one, I've highlighted the key points that you should know. If any of these symptoms sound familiar, be sure to check out the section below on what you can do to find relief.

1. Infraspinatus

This shoulder muscle spans most of the shoulder blade and attaches to the humerus. Its primary function is to assist in rotating the arm outward (external rotation) while also stabilizing the head of the humerus within the shoulder socket, ensuring smooth and controlled movement.

Symptoms it can Cause:

• Pain in the side, front, or back of the shoulder

• Weakness or stiffness in the shoulder and arm

• Restricted arm rotation

How it can be Triggered:

• Keeping the arms overhead or in front of the body for an extended period of time

• Driving a vehicle with the hands on top of the wheel

  
  

2. Scalenes

These muscles are located along the sides and front of the neck and play a crucial role in respiration by elevating the upper two ribs during inhalation. They also assist with neck flexion and lateral movement, contributing to overall posture and stability.

Symptoms they can Cause:

• Pain and numbness in the shoulder

• Pain, numbness, and tingling down the arm

How they can be Triggered:

• Excessive chest breathing or labored breathing

• Playing a wind instrument

• Chronic coughing

• Carrying heavy loads on the shoulders

3. Deltoid

This muscle covers the shoulder like a cap and consists of three distinct sections: the anterior, posterior, and lateral deltoid. It attaches to the collarbone and the spine of the scapula, extending about halfway down the humerus. The deltoid plays a crucial role in shoulder movement, helping to raise and rotate the arm in multiple directions, providing strength and stability for various upper-body motions.

Symptoms it can Cause:

• Shoulder pain

How it can be Triggered:

• Overusing the shoulder's full range of motion

• Swimming

• Weightlifting

4. Supraspinatus

This small muscle is found in the pocket above the shoulder blade. It functions to help raise the arm and hold the shoulder joint together.

Symptoms it can Cause:

• Deep ache in the outer shoulder

• Painful or difficult to raise the arm

• Clicking or popping in the shoulder joint

How it can be Triggered:

• Moving a heavy object

• Working with the arms overhead

• Typing on a keyboard with unsupported arms

How do we fix Triggered Muscles?

The good news is that triggered muscles can often be relatively quick and easy to release. However, if you continue the activity that caused the issue in the first place, the muscle will likely become triggered again. Consider how you can modify or mitigate these triggers—such as training yourself to breathe through your stomach or using arm support while typing at a computer. For activities that can't be adjusted, like mechanical or construction work that requires extensive, unsupported arm use, consistently applying the following two steps can help significantly reduce your pain.

Step 1: Relax the Muscle

The first step in releasing a triggered muscle is to relax it. Whether through using self-massage of your shoulder with a tennis ball or your hands, or seeking the help of a professional massage therapist, massage is the most effective way to ease muscle tension and restore movement. If you're interested in learning more about self-massage, I highly recommend The Trigger Point Therapy Workbook by Clair Davies, NCTMB.

Step 2: Strengthen and Stabilize

Relaxing the muscle alone is not enough. The reason it became overworked in the first place is often due to weakness—either in the muscle itself or in surrounding muscles that failed to provide adequate support. Developing a targeted corrective exercise routine to strengthen and stabilize your shoulders, back, and chest is essential for long-term relief. These exercises normally don’t require a gym and usually take just a few minutes each day, but the benefits will be well worth the effort!

If you are currently dealing with outer shoulder pain, schedule a consultation with me today to see how we can work together to help you feel and move better!

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