PRC Case Analysis & Practical Application 3 — Questions and Answers
Question 1: A patient cannot maintain a Zone of Apposition (ZOA) during exhalation. Which compensatory breathing pattern is most likely present?
- Bucket-handle rib motion with lateral costal expansion
- Accessory muscle breathing with scalene and SCM dominance (Correct answer)
- Paradoxical breathing with abdominal protrusion on inhalation
- Diaphragmatic breathing with full inferior costal expansion
Correct answer: Accessory muscle breathing with scalene and SCM dominance
Loss of ZOA leads to over-reliance on accessory muscles like scalenes and SCM to elevate the rib cage during inhalation as a compensatory strategy.
Question 2: In PRI, the term 'alternating reciprocal' refers to which concept?
- The alternating activation of left and right sides during gait and breathing (Correct answer)
- A treatment technique alternating manual and exercise-based interventions
- The reciprocal inhibition pattern between agonist and antagonist
- An alternating pattern of thoracic and lumbar extension
Correct answer: The alternating activation of left and right sides during gait and breathing
Alternating reciprocal activity refers to the normal left-right alternating pattern of muscle activation that PRI seeks to restore through repositioning.
Question 3: A patient presents with forward head posture, elevated right shoulder, and left lumbar scoliosis. Which combination of PRI patterns best explains this presentation?
- Right BC + Left AIC (Correct answer)
- Left BC + Right AIC
- Bilateral BC + TMCC
- Right BC + Right AIC
Correct answer: Right BC + Left AIC
Right BC causes right thoracic elevation and left thoracic convexity, while Left AIC produces left lumbar scoliosis and right pelvic forward rotation — together creating this clinical picture.
Question 4: Which finding would lead you to prioritize treating the Right BC pattern before addressing the Left AIC in a patient with both patterns?
- The patient's chief complaint is neck and shoulder pain rather than hip or low back pain (Correct answer)
- Right BC always precedes Left AIC in the treatment hierarchy
- Left AIC cannot be treated without first neutralizing thoracic rotation
- The patient's right hip is more restricted than the left
Correct answer: The patient's chief complaint is neck and shoulder pain rather than hip or low back pain
Treatment priority is guided by the patient's chief complaint and functional limitations; if BC-related symptoms dominate, the BC pattern is addressed first.
Question 5: A post-surgical knee patient demonstrates difficulty achieving full knee extension. PRI evaluation reveals an ipsilateral posterior innominate. How does this pelvic finding contribute to the knee problem?
- Posterior innominate increases hamstring length-tension advantage, reducing quadriceps recruitment needed for extension (Correct answer)
- Posterior innominate externally rotates the femur, mechanically blocking terminal knee extension
- Posterior innominate reduces lumbar lordosis, shifting weight posteriorly onto the knee
- Posterior innominate compresses the sciatic nerve, inhibiting distal quadriceps activation
Correct answer: Posterior innominate increases hamstring length-tension advantage, reducing quadriceps recruitment needed for extension
A posterior innominate positions the hamstrings with an advantage, inhibiting quadriceps activation through reciprocal inhibition and reducing drive for terminal knee extension.
Question 6: During gait assessment, a patient shows no contralateral pelvic drop on left stance phase. What PRI-based explanation is most likely?
- Right gluteus medius inhibition preventing left-side pelvic drop during right swing
- Left hip abductor over-facilitation preventing normal pelvic drop (Correct answer)
- Right hip adductor tightness elevating the left pelvis
- Absence of right AIC pattern preventing normal gait mechanics
Correct answer: Left hip abductor over-facilitation preventing normal pelvic drop
Over-facilitated left hip abductors in a Left AIC pattern prevent the normal contralateral pelvic drop, resulting in a stiff, non-alternating gait pattern.
Question 7: A patient has a positive right Adduction Drop Test but a negative left Adduction Drop Test. What does this asymmetry indicate?
- Right innominate is anteriorly rotated (Right AIC), with left innominate neutral (Correct answer)
- Right hip adductor is stronger than the left
- Left innominate is posteriorly rotated, causing right side compensation
- Bilateral AIC pattern with right-sided dominance
Correct answer: Right innominate is anteriorly rotated (Right AIC), with left innominate neutral
A positive Adduction Drop Test on the right indicates the right innominate is anteriorly rotated and the right hip is not in a neutral position, consistent with Right AIC.
PRC Case Analysis & Practical Application 3
A patient cannot maintain a Zone of Apposition (ZOA) during exhalation.
Which compensatory breathing pattern is most likely present?