The upper ribs (1–6) predominantly display a pump handle motion, which occurs primarily in the sagittal plane and is best palpated at the midclavicular line. With inhalation, the anterior portion of the rib moves anteriorly and superiorly. With exhalation, the anterior portion of the rib moves posteriorly and inferiorly.

The lower ribs (7–10) predominantly display a bucket handle motion, which occurs primarily in the coronal plane and is best palpated at the midaxillary line. With inhalation, the lateral margin of the rib moves superiorly and laterally, thus increasing the transverse diameter. With exhalation, the lateral margin of the rib moves inferiorly and medially, thus decreasing the transverse diameter.

The “floating” ribs (11–12) display caliper motion, which occurs primarily in the transverse plane and is best palpated just lateral to the T11–T12 transverse processes. With inhalation, they spread apart and move posteriorly. With exhalation, they approximate and move anteriorly.

The key rib is the predominant rib that is causing somatic dysfunction and thus is the preferred rib to treat. The B.I.T.E. mnemonic reminds us to treat the Bottom rib for Inhalation somatic dysfunctions and the Top rib for Exhalation somatic dysfunctions.

Remember that somatic dysfunctions of the ribs, like elsewhere in the body, are named for the motion of ease. If a rib moves normally during inhalation but is restricted during exhalation, the patient has an inhalation somatic dysfunction.