Course Instructor (P20)
Common Trigger Point Areas
6) Teres Major
- The Teres Major muscle originates at the inferior angle of the scapula and inserts at the lesser tubercle of the humerus. It is innervated by the lower subscapular nerve containing fibers from the 5th and 6th cervical nerves.
- The teres major muscle adducts the arm, assists in extending the arm when it is in a flexed position and assists in internal rotation.
- Teres Major T.P.’s refer pain to the posterior deltoid and the triceps brachii muscles.
- The Subscapularis muscle originates at the innermost (anterior) surface of the scapula (subscapular fossa). Its fibers pass in front of the shoulder joint and insert into the lesser tubercle of the humerus.
- It is innervated by the upper and lower subscapular nerves from spinal nerves C5, C6.
- This muscle helps to stabilize the shoulder by keeping the head of the humerus in the glenoid fossa and allows for internal rotation and adduction of the arm.
- Subscapularis T.P.’s will prevent being able to move the arm into abduction and external rotation. This inabilityis often diagnosed as frozen shoulder. The referred pain from these trigger points are found in the posterior shoulder and arm to the elbow.
- Codman’s exercise is performed to stretch the subscapularis. Have the patient lean over a chair with the involved arm hanging down. The patient then passively swings the arm by moving the body, not by actively using the shoulder muscles.
8) Sacrospinalis / Erector Spinae
- The superficial (erector spinae) group, the Longissimus Thoracics, Iliocostalis Thoracics, and Iliocostalis Lumborum are paraspinal muscle fibers.
- A) Longissimus Thoracics – has the longest paraspinal muscle fibers. Its origin is the transverse processes of all the thoracic vertebrae adjacent to the 1st to 10th ribs. It inserts at the lumbar transverse processes.
- B) Iliocostalis Thoracics – this muscle originates at the transverse process of C7 and to the first 6 ribs. It inserts into the lower 6 ribs.
- C) Iliocostalis Lumborum – this muscle attaches from the sacrum to the lowest 6 ribs.
- These muscles are innervated by the dorsal primary divisions of the spinal nerves. When acting bilaterally they extend the spine. When acting unilaterally they cause lateral flexion to the same side.
- Prolonged sitting is a common cause of erector spinae trigger point activation. The Longissimus Thoracics muscle will refer pain to the lower buttock. The Iliocostalis Thoracics refers pain upward into the shoulder. The Iliocostalis Lumborum refers pain downward to the buttock.
9) Quadratus Lumborum Muscle
- The Quadratus Lumborum Muscle originates from the iliac crest and the iliolumbar ligament and inserts above into the medial 1/2 of the inferior border of the last rib, as well as the apices of the transverse processes of LI to L4. It is innvervated by the 12th thoracic and the upper 4 lumbar nerves.
- The quadratus lumborum muscle is a lateral flexor of the spine to the same side when the pelvis is fixed. The muscle extends the lumbar spine when it acts bilaterally.
- Quadratus lumborum T.P.’s refer pain along the crest of the ilium to the adjacent lower quadrant of the abdomen, the upper groin, greater trochanter, the upper thigh, across the upper sacral region and into the lower buttock.
- Quadratus Lumborum TP’s can be activated by improper lifting of a heavy load and twisting of the torso.