It is located in the uppermost part of the arm, at the shoulder. Tendons attach the deltoid to the collarbone, shoulder blade, and upper arm.
Like many other muscles, the deltoid can be sore for a variety of reasons, including overuse and tendon injuries.
In this article, we explore the causes of deltoid pain. We also describe home remedies and treatments that can provide relief.
The deltoid muscle is located at the uppermost part of the arm.
When the deltoid muscle is injured, a person may feel pain or tenderness at the front, side, or back of the shoulder, especially when lifting the arm.
In some cases, the deltoid muscle may be torn and cause swelling and bruising.
Strains are given a grade of 1–3, according to their severity:
- Grade 1: These mild strains are characterized by tightness in the muscle and minimal swelling. Using the arm may produce slight pain, but the range of movement is often not restricted.
- Grade 2: Increased pain, swelling, and limited movement are typically present with a grade 2 strain. In many cases, doing push-ups, presses, or lifting the arm in any direction can cause pain.
- Grade 3: These serious injuries can cause severe pain, swelling, and a muscle bulge or gap. Due to the pain, movement of the arm may be severely limited or impossible.
A deltoid strain can lead to symptoms ranging from a mild tightness of the muscle to severe, restricting pain.
For mild injuries caused by overuse, a doctor may recommend adjusting exercise routines to accommodate the injury and prevent it from worsening.
Many people, including athletes, may need to decrease the intensity and duration of their workouts or sports practices while their shoulders heal.
People can also use over-the-counter anti-inflammatories, such as ibuprofen or naproxen, to reduce inflammation, swelling, and discomfort.
A doctor may recommend the following treatments, depending on the severity of the strain:
- For a grade 1 deltoid strain: To reduce swelling, use a compression wrap and apply ice periodically for 24 hours after the injury. Later, use a heating pad to relieve pain and tension. It is also essential to allow the shoulder to rest.
- For a grade 2 deltoid strain: Applying ice periodically for 3–5 days can reduce swelling. After an acute injury, alternating between ice and heat packs can also help to relieve pain. Allow time for the injury to heal, and reduce the length and intensity of exercise routines during this period.
- For a grade 3 deltoid strain: Apply ice to the injury, elevate it when possible, and try to avoid using the affected arm and shoulder. Over-the-counter painkillers can reduce discomfort.
If the pain does not diminish over time with these home remedies, a physician or a rehabilitation specialist can offer additional recommendations designed to speed recovery and manage pain.
Exercises and stretches
As with any form of exercise, it is vital to warm up, cool down, and stretch. Doing so will help to protect the deltoid. To improve flexibility and prevent injury, stretches should involve the shoulder and deltoid.
Gradual strength training and conditioning can also help to prevent strain and injury. When a person is recovering from a deltoid injury, gentle stretching can help to reduce pain.
Deltoid stretches and exercises include:
Bend forward at a roughly 45-degree angle and let the affected arm dangle. Gently swing the arm back and forth for 3–5 minutes to loosen the muscles around the shoulder and relieve pain.
Standing in front of a doorframe, place the forearms on either side of the frame and lean into the doorway for 30 seconds at a time.
While standing upright or sitting in a chair, pull the affected arm across the chest, using the other arm to create slight tension. Hold for 30 seconds.
Lying flat, raise the affected arm so that the fingertips point toward the ceiling. Use the other arm to help support it, if necessary. Keeping the arm straight, swing it a few inches backward toward the head then forwards toward the knee for 3–5 minutes.
In a standing position, bring the arms behind the back and clasp the hands together. Gently lift the hands toward the ceiling as far as is comfortable.
The most common causes of deltoid pain are overuse injuries and strains. People who use their shoulders and deltoid muscles repetitively, especially athletes, have an increased risk of deltoid injury.
A strain can suddenly result from heavy lifting or an accident, such as a trip or fall.
Most injuries to the deltoid muscle take time to develop and are caused by activities such as swimming, lifting weights, or playing baseball.
People can help prevent deltoid pain and shoulder injuries by:
- warming up sufficiently before beginning a workout
- taking "rest days" to allow the muscle to recover after exercising
- stretching before and after exercise
- if the injury is work-related, ensuring that the proper safety equipment is used and following other best practices
- having regular sports massages to relieve tension in the muscles
Sports therapists, fitness trainers, and medical professionals may be able to offer tailored advice and suggestions on preventing injuries while playing a particular sport.
When to see a doctor
People can often treat overuse injuries and strains at home with over-the-counter remedies and therapies.
To avoid developing a chronic problem, it may be a good idea to speak with a doctor, physical therapist, or occupational therapist about preventing further injuries.