PRC Neuromuscular Integration & Movement Patterns 3 — Questions and Answers
Question 1: The Posterior Exterior Chain (PEC) in PRI refers to the integration of which primary structures?
- Thoracolumbar fascia, paraspinals, and posterior cervical muscles
- Hamstrings, gluteus maximus, thoracolumbar fascia, and posterior shoulder complex (Correct answer)
- Gastroc-soleus, posterior tibialis, and plantar fascia
- Quadratus lumborum, iliolumbar ligament, and iliacus
Correct answer: Hamstrings, gluteus maximus, thoracolumbar fascia, and posterior shoulder complex
The PEC integrates the hamstrings, gluteus maximus, thoracolumbar fascia, and posterior shoulder girdle as a continuous myofascial chain influencing extension and rotation patterns.
Question 2: During a PRI-based step test, a patient shows an inability to shift weight left. This is most commonly associated with:
- Bilateral hip abductor weakness
- Left hip joint pathology only
- Inability to achieve left acetabular-femoral orientation due to right AIC patterning (Correct answer)
- Right ankle instability limiting weight transfer
Correct answer: Inability to achieve left acetabular-femoral orientation due to right AIC patterning
Difficulty shifting left during the step test typically reflects the right AIC pattern where the left acetabulum cannot properly orient over the femoral head to accept load.
Question 3: Which of the following describes the neuromuscular role of the left adductor magnus in PRI theory?
- It acts as a hip extensor-internal rotator that counters right pelvic forward rotation (Correct answer)
- It primarily externally rotates the left femur during stance phase
- It provides direct attachment to the pelvic floor for continence control
- It functions as a secondary hip abductor during single-leg stance
Correct answer: It acts as a hip extensor-internal rotator that counters right pelvic forward rotation
The left adductor magnus is emphasized in PRI as a key hip extensor and internal rotator that counters the forward rotation of the right pelvis seen in the Left AIC pattern.
Question 4: A PRI clinician observes that a patient's left rib cage is more elevated and externally rotated than the right. This finding is most consistent with:
- Left thoracic outlet syndrome
- Left-sided PEC dominance with posterior mediastinum inhibition
- Right TMCC pattern influencing the left thorax (Correct answer)
- Isolated left serratus anterior weakness
Correct answer: Right TMCC pattern influencing the left thorax
The Right TMCC (Temporal Mandibular Cervical Chain) pattern can influence thoracic cage positioning, and right temporal-cervical dominance often correlates with left thoracic cage elevation.
Question 5: In PRI gait analysis, the left gluteus medius ideally fires during which phase to stabilize the pelvis?
- Right loading response through mid-stance, when the right foot is on the ground (Correct answer)
- Left toe-off into left swing phase
- Right terminal swing to decelerate the right limb
- Bilateral stance phase only
Correct answer: Right loading response through mid-stance, when the right foot is on the ground
The left gluteus medius must fire during right loading response and mid-stance to prevent contralateral (right) pelvic drop and maintain proper pelvis position over the left stance limb.
Question 6: Femoroacetabular orientation in PRI is considered most optimal when the femoral head is positioned:
- Anteriorly in the acetabulum with the pelvis in anterior tilt
- Concentrically within the acetabulum with the pelvis in a neutral position (Correct answer)
- Posteriorly in the acetabulum to maximize hip extension leverage
- Superiorly in the acetabulum to increase joint compression
Correct answer: Concentrically within the acetabulum with the pelvis in a neutral position
PRI emphasizes concentric femoral head positioning within the acetabulum, achieved when the pelvis is in neutral, to allow full triplanar hip mobility and proper neuromuscular sequencing.
Question 7: When a PRI patient cannot achieve a posterior pelvic tilt during a supine test, the primary neuromuscular explanation is:
- Shortened hip flexors preventing pelvic movement
- Overactive psoas and underactive abdominals preventing posterior rotation (Correct answer)
- Weak gluteus maximus making hip extension impossible
- Tight hamstrings blocking sacral counternutation
Correct answer: Overactive psoas and underactive abdominals preventing posterior rotation
Inability to posteriorly tilt the pelvis in PRI is most often attributed to an overactive psoas combined with underactive abdominals, perpetuating the anterior pelvic tilt pattern.
PRC Neuromuscular Integration & Movement Patterns 3
The Posterior Exterior Chain (PEC) in PRI refers to the integration of which primary structures?