Muscle Test Group: Rhomboid major, rhomboid minor, levator scapulae.
• Rhomboids and levator scapulae are tested together as a muscle group.
• This muscle group is responsible for adduction, elevation, and downward rotation of the scapula.
Muscle Function of Rhomboid Major/Minor: Scapular adduction or retraction, elevation, and downward rotation so that the glenoid cavity faces caudally. It also fixes the scapula to the thoracic wall.
Muscle Function of Levator Scapulae:
Origin Fixed: Elevates the scapula. Assists in downward rotation so that the glenoid cavity faces caudally.
Insertion Fixed and Acting Unilaterally: Laterally flexes the cervical vertebrae, and rotates toward the same side.
Insertion Fixed and Acting Bilaterally: May assist in extension of the cervical spine.
Palpation: Medial to the vertebral border of the scapula. Fibers run in a diagonal direction, originating from the vertebrae traversing to insert into the medial border of the scapula. Rhomboid major and minor are inferior to where the levator scapulae is.
Strength Testing: Position – the subject in prone with the arm at the edge of the table on the side being tested. The elbow is flexed; the humerus is adducted toward the side of the body in slight extension and slight lateral rotation. Stabilize – the shoulder and the elbow. Resist – against adduction and downward rotation of the scapula by applying pressure against the arm to determine the ability of the rhomboids to hold the scapula in test position.
Possible Substitutions: Pectoralis minor, trapezius, and latissimus or posterior deltoid. For the latissimus and posterior deltoid, be sure that there is scapular motion and not just humeral motion to avoid this substitution. For the trapezius, monitor the rotation of the scapula to avoid this substitution.
• Roots: C4, C5.
• Nerve: Dorsal scapular nerve.
• Innervation Route: C4, C5 → dorsal scapular nerve → rhomboid major and minor branches.
Origins of Rhomboid Major: Spinous processes of T2 through T5 vertebrae.
Insertion of Rhomboid Major: By fibrous attachment to medial border of scapula between spine and inferior angle.
Origins of Rhomboid Minor: Ligamentum nuchae, spinous processes of C7 and T1 vertebrae.
Insertion of Rhomboid Minor: Medial border at root of spine of scapula.
• Roots: C3, C4, C5.
• Nerve: Cervical (C3, C4); dorsal scapular nerve (C5).
• Innervation Route:
• C3, C4 → levator scapulae branches.
• C4, C5 → dorsal scapular nerve → levator scapulae branches.
Origins: Posterior tubercles of transverse processes of C1 through C4 vertebrae.
Insertion: Medial border of scapula between superior angle and root of spine.