Gravity-lessened Test: Position ““prone. The hand of the arm being tested is placed on the buttock on the same side, with the shoulder adducted, medially rotated, and extended with elbow extension. Stabilize ““ on the table. Resist ““ on the forearm against adduction and extension with the shoulder in medial rotation without scapular motion. Primary emphasis for resistance is against shoulder adduction. Subject can be asked to reach for his opposite foot.
Anti-gravity Test: Same as the gravity-lessened test except that the primary emphasis for resistance is against shoulder flexion.
Alternate Anti-gravity Test: This muscle may also be tested in sitting with a gross test being a chair pushup from a sitting position. The patient is asked to place their arms on the chair and to push up and out of the chair with their arms supported on the chair. In this test position, the latissimus dorsi is assisted by the triceps brachii and pectoralis muscles. This is considered more of a functional test rather than a specific manual muscle test.
Possible Substitutions: Lateral abdominals, posterior deltoid, teres major, quadratus labarum, and the elbow flexion using biceps if resistance is given distally. See palpation details on exam for techniques to assess.
Origin: Spinous processes of inferior six thoracic (T6-T12) vertebrae, last three or four ribs, through the thoracolumbar fascia from lumbar and sacral vertebrae and posterior â…“ of external lip of iliac crest, and a slip from inferior angle of scapula.
Insertion: Intertubercular groove of humerus.