Pump-Handle Motion
Ribs 1–5 (increases AP diameter around transverse axis)
Bucket-Handle Motion
Ribs 6–10 (increases transverse diameter around AP axis)
Caliper Motion
Ribs 11–12 (glide posterior/inferior on inhalation)
Key Rib Rule
Inhalation dysfunction: treat BOTTOM rib; Exhalation: treat TOP rib
Rib Classifications & Primary Mechanics
The 12 pairs of ribs articulate posteriorly with thoracic vertebrae and are anatomically and functionally grouped:
True Ribs (Ribs 1–7)
Attach directly to the sternum via individual costal cartilages.
False Ribs (Ribs 8–10)
Attach indirectly to the sternum via the costal cartilage of the rib immediately superior.
Floating Ribs (Ribs 11–12)
Have no anterior sternal or cartilaginous attachment. Articulate only with vertebral bodies and float within the abdominal wall musculature.
Respiratory Kinematics: Pump vs. Bucket vs. Caliper
Motion during respiration occurs along three distinct mechanical profiles:
| Rib Group | Primary Motion | Plane & Axis of Motion | Landmark Palpation Site |
|---|---|---|---|
| Ribs 1–5 | Pump-Handle (AP expansion) | Sagittal plane around coronal/transverse axis | Anterior chest wall mid-clavicular line |
| Ribs 6–10 | Bucket-Handle (Transverse expansion) | Coronal plane around anteroposterior (AP) axis | Mid-axillary line |
| Ribs 11–12 | Caliper (Pincher expansion) | Horizontal plane around vertical axis | Posterior-lateral rib tips (glide post/inf in inhalation) |
Inhalation vs. Exhalation Somatic Dysfunctions
Group rib somatic dysfunctions are characterized by which phase of respiration they remain stuck in:
Inhalation Somatic Dysfunction
Ribs move freely into inhalation and are restricted in exhalation. Anterior rib edge is displaced inferiorly / locked up. Treatment rule: Treat the LOWEST (bottom) rib of the dysfunctional group first (the key rib holding the others up).
Exhalation Somatic Dysfunction
Ribs move freely into exhalation and are restricted in inhalation. Anterior rib edge is displaced superiorly / locked down. Treatment rule: Treat the UPPERMOST (top) rib of the dysfunctional group first (the key rib preventing the group from lifting).
Muscle Energy Respiratory Key Muscles
Treating exhalation somatic dysfunctions with muscle energy activates specific respiratory accessory muscles:
| Key Rib Level | Target Muscle Contracted | Patient Action / Head Position |
|---|---|---|
| Rib 1 | Anterior & Middle Scalenes | Head straight back against resistance |
| Rib 2 | Posterior Scalene | Head turned 30° away, lift toward ceiling |
| Ribs 3–5 | Pectoralis Minor | Push elbow toward opposite ASIS from adducted position |
| Ribs 6–9 | Serratus Anterior | Push elbow straight anteriorly against resistance |
| Ribs 10–11 | Latissimus Dorsi | Adduct arm against resistance |
| Rib 12 | Quadratus Lumborum | Hike hip toward shoulder against resistance |
COMLEX / OMM Integration
NBOME High-Yield Correlate
Rib Raising & Sympathetic Tone
- Anatomical Basis: The sympathetic chain ganglia lie directly anterior to the rib heads on each side of the thoracic spine.
- Clinical Effect: Rhythmic rib raising initially produces a transient burst of sympathetic output, followed by lasting sympathetic inhibition and normalization. Essential for pneumonia, asthma, and post-op ileus prevention.
- Clinical Effect: Rhythmic rib raising initially produces a transient burst of sympathetic output, followed by lasting sympathetic inhibition and normalization. Essential for pneumonia, asthma, and post-op ileus prevention.
Board Traps & Common Distractors
- Mnemonic Trap: Inhalation = lowest rib (I-L); Exhalation = top rib (E-T). Remember: 'Inhale Lower, Exhale Top'.
- Rule of Threes (Thoracic Spinous Processes): T1–T3 = SP at level of TP; T4–T6 = SP halfway between TP of same and vertebra below; T7–T9 = SP at level of TP of vertebra below; T10 = like T7-9; T11 = like T4-6; T12 = like T1-3.