Manual Muscle Testing: Trunk Extension

"'original editor"'-Ruchi Desai

"'Top contributors"'-Lucinda hampton, Ruchi Desai and Kim Jackson

Muscles Involved:

  • Iliocostalis thoracis
  • Iliocostalis lumborum
  • Longissimus thoracis
  • Spinalis thoracis (often indistinct)
  • lumborum
  • Semispinalis thoracis
  • Multifidi
  • Rotatores thoracis and lumborum (11pairs)
  • Interspinales thoracis and lumborum
  • Intertransversarii thoracis
  • Quadratus lumborum

Patient Positioning :

Lumbar Spine

Grade 5 and Grade 4: Prone with fingertips lightly touching the side of the head and shoulders in external rotation.

The weight of the head and arms essentially substitutes for manual resistance by therapist.

Thoracic Spine

Grade 5 and Grade 4

Position of Patient:

Prone with head and upper trunk extending off the table from about the nipple line (Fig. 4.5).

Hands should be lightly touching the side of the head, with shoulders and elbows retracted (back).

Grade 3,2,1,0: Prone with arms at sides.(Grades 3, 2, 1, and 0 tests involve the lumbar and thoracic spine.)

Grade 5, 4, 3,2,1,0 : Stand at side of patient to stabilize the lower extremities just above the ankles. Ask patient to raise the head, shoulders, and chest off the table. Observe quality of motion and ability to hold the test position.

Alternate Instructions to Therapist:

If the patient has hip extension weakness, stabilize the lower extremities by leaning firmly over the patient's body, placing both arms across the pelvis.

Thoracic Spine

Therapist Position :

Stand at side of patient to stabilize the lower limbs at the ankle. Ask patient to raise the head, shoulders, and chest to table level.

To Test:

Patient extends the lumbar spine until the entire trunk is raised from the table (clears umbilicus).

Thoracic Spine:

Patient extends thoracic spine to the horizontal. This will be a small movement, and care should be made not to extend farther than horizontal because further movement will cause lumbar extension.

Grade 3:

Patient extends spine, raising body from the table so that the umbilicus clears the table

Grade 2, Grade 1, and Grade 0:

These tests are identical to the Grade 3 test except that the therapist must palpate the lumbar and thoracic spine extensor muscle masses adjacent to both sides of the spine. The individual muscles cannot be isolated.[1]


  1. Hislop H, Avers D, Brown M. Daniels and Worthingham's muscle Testing-E-Book: Techniques of manual examination and performance testing. Elsevier Health Sciences; 2013 Sep 27.