Before you read about trigger points in the deltoid muscles and their referred pain patterns, you may want to find out more about the deltoid muscles themselves.
The deltoid, being the main muscle of the shoulder joint, as stated in the article linked above is active during any lifting movement and contracts statically during most everyday tasks.
The deltoid is activated for long periods of time during keyboard work and driving. If a keyboard or work surface is set too low or too high, this activation is increased. Driving with the hands on the top of the steering wheel primarily activates the anterior deltoid. Trigger points can develop from over-use through these mechanisms or through the abuse the muscle frequently receives in resistance training, as many bodybuilders and strength trainees dedicate entire workouts to the shoulder alone. Since the deltoid is also active during most other upper body movements during other workouts, over-use can easily produce TP’s. The trigger points cause pain in the deltoid muscle itself which is felt as a deep pain the shoulder.
Trigger points may also develop after direct impact trauma to the muscle during sports. The functional characteristics of the deltoid and the supraspinatus becomes much more complicated during sporting movements such as throwing or with sports requiring shoulder abduction and external rotation. The remainder of this article will cover the primary movements only as sport-specific functions are beyond its scope.
Deltoid Trigger Points Causes and Symptoms
As stated above, trigger points can be activated in the deltoid by an impact trauma such as a direct blow or fall on the shoulder; or by over-use of the muscle. Also, any accident that traumatizes the deltoid muscle, such as reaching out to catch oneself during a fall, can activate trigger points. Unlike most other trigger points, however, deltoid trigger points do not refer pain to a remote area. The pain tends to be concentrated in the immediate area of the TrP and occurs primarily during shoulder movements while not occurring often during rest. Continuous pain in the shoulder is more likely to come from some other underlying pathology or trigger points in other muscles that refer pain to the shoulder area. For instance, a continuous dull ache in the shoulder is more likely to trigger points in the rotator cuff muscles.
When pain occurs in the shoulder joint during passive mobilization with scapula rotation and elevation, as opposed to active shoulder movements, this is more likely to indicate a sprain or subluxation of the acromioclavicular joint, the pain pattern of which mimics the pain pattern of anterior deltoid trigger points.
The pain from deltoid trigger points occurs deep in the deltoid and there may be difficulty in raising the arm or reaching back with the arm at shoulder level. Trigger points of the deltoid tend to occur in the anterior and posterior portions of the muscle although the posterior part rarely develops trigger points alone as the result of activity but rather develops them in association with TrP’s in other muscles. Trigger points may sometimes develop in the middle portion of the muscle but how often this occurs, according to various texts, is unclear. Davies reports that the lateral deltoid is the portion where trigger points most often occur while Travell and Simons, and others report that they are rare. However, when they do occur, the multipennate arrangement of these fibers means that the trigger points are likely to be sprinkled anywhere along the lateral upper arm. Davies erroneously reports that the middle fibers are more likely to develop trigger points because this portion of the muscle is the “largest part of the muscle and works the hardest.” 1Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 28: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 431-438. Print.,2Scheumann, Donald W. “Chp. 7: Aligning the Upper Extremity.” The Balanced Body: a Guide to Deep Tissue and Neuromuscular Therapy. Philadelphia: Lippincott Williams & Wilkins, 2007. 118. Print.,3Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004. Print.,4Davies, Clair. “Chp. 6: Shoulder Treatment, Part B.” Frozen Shoulder Workbook: Trigger Point Therapy for Overcoming Pain & Regaining Range of Motion. Oakland, CA: New Harbinger Publications, 2006. 150-51. Print.
However, the front deltoid is much more likely to receive overload and trauma during everyday activities and during exercise and sports and there is no basis for claiming that the largest portion of a muscle is the most likely to be overworked. While the arrangement of the lateral deltoid’s fibers gives it the most strength over a short distance this is due to its functional roles and not necessarily its every-day workload. Reliable information on the frequency of middle fiber trigger points over anterior and posterior ones has been difficult to locate for the purposes of this article. Check for trigger points anywhere in the lateral upper arm if you experience deep pain in this area and suspect lateral deltoid trigger points.
Anterior Deltoid Trigger Points
When you have pain and difficulty while combing your hair, eating, or, in general, bringing your hand to your face this may be due trigger points in the anterior (front) deltoid. This part of the muscle is highly likely to receive a traumatic impact in many sports and can be suddenly overloaded by reaching out to catch a fall, such as when one stumbles on the stairs. Overuse occurs in the workplace when having to hold heavy tools or any job that requires frequent forward reaching. Exercise and sports activities that require a great deal of forward shoulder flexion such as swimming, skiing, and ball throwing may overload the muscle. And, as mentioned, shoulder abuse by improper emphasis of the shoulders in resistance training can strain and overload the muscle, setting up trigger points.
Anterior deltoid trigger points are usually located high in the front margin of the muscle, in front of the glenohumeral joint, or lower toward the midpoint. The referred pain pattern is in the area of the front shoulder surrounding the trigger point with some spillover pain further down the arm and posterior to the TP. See Trigger Point Figure 1 above for trigger point locations and Figure 2 below for pain patterns.
Posterior Deltoid Trigger Points
The posterior deltoid usually develops TrP’s in conjunction with other muscles such as the long head of the triceps, the latissimus dorsi, and the teres major. They may also be over-exerted, as by polling during skiing or other activities where the arm is frequently extended toward the back. TP’s may also be activated by local intramuscular injection of irritable solutions such as B vitamins, penicillin or various vaccines, after which the TP’s are self-sustaining.
Trigger points in the posterior deltoid tend to be located on the lower posterior margin of the muscle and upward toward the midpoint. The pain is referred to the immediate surrounding area of the TP in the back of the shoulder with some spillover pain further down the arm and anterior to the TP.
Deltoid Trigger Point Release
Don’t try to use your hands to massage your own deltoids because it is too difficult a position to apply pressure and your hands will become exhausted and over-used. Instead, use a tennis or lacrosse ball against the wall. Place the ball against the trigger point area, lean into it, and roll the ball up and down over the area. It may help to place the ball in an old sock so that the end of the sock can be used as a handle. Also, smaller hard rubber bouncy balls can be used when you are ready to apply more precise pressure.
Sources [ + ]
|1.||↲||Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. “Chp. 28: Masseter Muscle.” Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 431-438. Print.|
|2.||↲||Scheumann, Donald W. “Chp. 7: Aligning the Upper Extremity.” The Balanced Body: a Guide to Deep Tissue and Neuromuscular Therapy. Philadelphia: Lippincott Williams & Wilkins, 2007. 118. Print.|
|3.||↲||Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004. Print.|
|4.||↲||Davies, Clair. “Chp. 6: Shoulder Treatment, Part B.” Frozen Shoulder Workbook: Trigger Point Therapy for Overcoming Pain & Regaining Range of Motion. Oakland, CA: New Harbinger Publications, 2006. 150-51. Print.|