ERECTOR SPINAE

ILIOCOSTALIS THORACIS, ILIOCOSTALIS LUMBORUM, LONGISSIMUS THORACIS, SPINALIS

Of the three muscles identified as part the erector spinae group (iliocostalis, longissimus, and spinalis), iliocostalis and longissimus are considered to be the most clinically significant in most cases. The spinalis is the most medially placed muscle of the group. It is generally poorly developed and has little clinical significance; it is therefore not included in our discussion.

Proximal attachment: Iliocostalis thoracis: angles of the upper six ribs. Iliocostalis lumborum: angles of the lowest six ribs. Longissimus thoracis: transverse processes of all thoracic vertebrae and adjacent ribs.

Distal attachment: Iliocostalis thoracis: angles of the lowest six or seven ribs. Iliocostalis lumborum and longissimus thoracis: via the shared lumbocostal aponeurosis of the erector spinae, attaching to the transverse processes of the lumbar vertebrae (L1–L5) and to the sacrum, iliac crest, and spinous processes of the lumbar vertebrae.

Action: Acting bilaterally: extension of the trunk. Acting unilaterally: lateral bending to the same side. The erector spinae muscles contract strongly while coughing or straining to have a bowel movement.

Palpation: The erector spinae are the superficial layer of the paraspinal muscles. They are considered the “true” back muscles due to their work of maintaining posture and their direct action on movement of the vertebral column.

For the purpose of palpation, iliocostalis and longissimus should be considered as one group. To locate iliocostalis and longissimus, identify the following structures:

• Spinous processes of T1–T12
• Spinous processes of L1–L5. Note the change in shape and size of the lumbar spinous processes as compared to the thoracic spinous processes.
• Sacrum
• Iliac crest—Lying on a horizontal line with the junction of L4–L5

To palpate the erector spinae, place your hands parallel to the spine, fingers together, hands flat and relaxed, with your index fingers adjacent to but not touching the spinous processes. With firm but gentle pressure, palpate through the overlying trapezius and latissimus dorsi. Your hand movement follows the vertical course of fiber direction. As you move throughout the course of the muscle you may note cord- or ropelike consistency within areas of the musculature. This is a commonly found indicator of myofascial constriction.

You may begin at either end of the spine, but palpate bilaterally and throughout the course of the musculature to assess the condition of the complete muscle group. Differentiate between the superficial musculature and the deeper erector spinae by noting the direction of the muscle fibers. Note that it may be difficult to differentiate between iliocostalis and longissimus.

Focus on the palpation of iliocostalis thoracis by assessing the condition of the most laterally placed vertical bands of muscle lying lateral to T1–T12. Focus on the palpation of iliocostalis lumborum by assessing the condition of the most laterally placed vertical bands of muscle lying lateral to T7–T12 and extending downward over the lumbar region to the sacrum and iliac crests.

To palpate longissimus thoracis, begin close to the transverse processes of the thoracic vertebrae and the adjacent ribs. Follow fiber direction to the lumbar region where the lumbocostal aponeurosis attaches to the sacrum and iliac crests. With focused palpation, try to differentiate between the laterally placed slips of iliocostalis and the more medially placed slips of longissimus. It may be difficult to differentiate the two groups.

Pain pattern: Iliocostalis thoracis: pain in the thoracic region of the back and sometimes the abdomen, with restriction of spinal motion. Iliocostalis lumborum: pain is referred downward, low in the buttock and along the iliac crest. Longissimus thoracis: pain is referred low in the buttock. When trigger points are located bilaterally at the level of L1, the patient will have difficulty rising from a chair and/or climbing stairs.

Causative or perpetuating factors: Sudden overload through improper lifting; sustained overload resultant from postural stresses (hyperlordosis); immobility for extended periods of time.

Satellite trigger points: Each muscle of the erector spinae group may develop satellite trigger points in response to the presence of trigger points in any other muscle of the group. Additional trigger points might also be found in the latissimus dorsi and quadratus lumborum muscles.

Affected organ systems: Due to the placement of the shu (chronic disease) points along this region, constriction of regions of this muscle may reflect the condition of the following organs. Iliocostalis thoracis: lung, stomach, gallbladder, liver, and spleen. Iliocostalis lumborum: stomach, gallbladder, liver, spleen, kidney, and colon. Longissimus thoracis: lung, stomach, gallbladder, liver, spleen, kidney, and colon. We have observed constriction in this muscle between T6 and T12 in patients suffering with diabetes.

Erector spinae pain pattern

Associated zones, meridians, and points: Dorsal zone; Foot Tai Yang Bladder meridian; Iliocostalis thoracis: BL 11–21, BL 41–50; Iliocostalis lumborum: BL 16–26, BL 45–52; Longissimus thoracis: BL 11–25, BL 41–52.

Stretch exercises:

1. Seated forward stretch: Sit comfortably on a chair with the feet placed flat on the floor. Fold the torso toward the floor, reaching forward and down with the arms. Allow your head and neck to hang loosely. Hold this position for a count of twenty to thirty. Return to the seated position slowly.
2. Pelvic tilts: Lie supine. Bend the knees, placing the soles of the feet on the floor. Exhale and slowly drop the lumbar curve of the back toward the floor. Hold for a count of five, then release. Repeat several times. Be certain that the drop of the lumbar arch occurs as a result of the relaxation of the back muscles, not from an anterior tilt of the lower pelvis brought on by contracting the gluteal muscles.
3. Cats: Position the body on the hands and knees. Arch the back, lifting both the head and the buttocks toward the ceiling. Hold for a count of five. Then round the back, aiming both the head and the coccyx for the floor. Hold for a count of five. Alternate these two positions three to four times.

Strengthening exercise: Lie prone, with the hands clasped behind the head. Lift the upper portion of the body from the floor, making sure to keep the buttocks and legs relaxed. Hold for a count of one to three.

Repeat two or three times, increasing frequency and duration as the strength of the back increases.

Stretch exercise 1: Erector spinae

Stretch exercise 2: Erector spinae

Stretch exercise 3: Erector spinae

Quadratus lumborum and trigger points