PRC Technology & Digital Tools 3 — Questions and Answers
Question 1: Surface EMG is used during a PRI wall supported hip flexor stretch. Which muscle activation sequence confirms the patient has achieved a posterior pelvic tilt without hip flexor dominance?
- Transversus abdominis fires before rectus femoris quiets (Correct answer)
- Rectus femoris amplitude increases before abdominal activity
- Erector spinae activity precedes gluteus maximus
- Hamstring amplitude decreases while hip flexors increase
Correct answer: Transversus abdominis fires before rectus femoris quiets
Proper PRI technique requires deep abdominal (TA) activation to occur before the superficial hip flexors inhibit, confirming ZOA-driven pelvic repositioning.
Question 2: A digital pressure mapping platform shows a patient consistently offloading the right heel during bilateral stance. This finding is most consistent with which PRI pattern?
- Left AIC with right stance phase dominance (Correct answer)
- Bilateral PEC with symmetric loading
- Right BC causing left unloading
- Neutral pelvis with right ankle instability only
Correct answer: Left AIC with right stance phase dominance
Left AIC pattern shifts weight toward the right lower extremity during stance, causing relative right heel offloading as the pelvis rotates and the right hip extends.
Question 3: Which software-based outcome measure is most validated for tracking functional improvements in patients undergoing PRI-based postural correction?
- Numeric Pain Rating Scale combined with PSFS entered in a digital form (Correct answer)
- VO2 max testing via metabolic cart software
- HRV analysis via wearable ECG patch
- Digital CT vertebral morphology grading
Correct answer: Numeric Pain Rating Scale combined with PSFS entered in a digital form
Patient-specific functional scale (PSFS) combined with numeric pain rating, captured via digital intake forms, provides a validated, sensitive measure of functional change in musculoskeletal settings including PRI-based care.
Question 4: A PRC uses ultrasound imaging to assess diaphragm excursion during a PRI breathing technique. A normal caudal excursion of the right hemidiaphragm during inhalation is approximately:
- 1.5–2.5 cm during quiet breathing, up to 7–8 cm with deep breath (Correct answer)
- 0.2–0.5 cm during quiet breathing, up to 1 cm with deep breath
- 5–6 cm during quiet breathing, up to 12 cm with deep breath
- 3–4 cm with every breath regardless of depth
Correct answer: 1.5–2.5 cm during quiet breathing, up to 7–8 cm with deep breath
Normal right hemidiaphragm excursion is 1.5–2.5 cm during tidal breathing and can reach 7–8 cm during maximal inhalation when assessed with M-mode ultrasound.
Question 5: In a PRI-integrated clinical setting, which app feature would MOST help a patient perform the correct reciprocal arm/leg pattern during gait retraining at home?
- Real-time metronome with auditory cueing synced to step frequency (Correct answer)
- Step counter tracking total daily distance walked
- Heart rate zone alerts via Bluetooth watch
- GPS route mapping with elevation grade display
Correct answer: Real-time metronome with auditory cueing synced to step frequency
A metronome app providing auditory cues at the target step cadence helps patients time reciprocal limb patterns during gait retraining without a clinician present.
Question 6: Which digital measurement approach is most appropriate for a PRI clinician remotely verifying that a patient's rib cage has descended during the exhale phase of a repositioning exercise?
- Asking the patient to hold a plumb line at the xiphoid while the camera captures lateral rib cage position change (Correct answer)
- Using the device accelerometer to measure core temperature change
- Instructing the patient to step on a digital scale before and after exhale
- Checking oxygen saturation via phone camera photoplethysmography
Correct answer: Asking the patient to hold a plumb line at the xiphoid while the camera captures lateral rib cage position change
A lateral view with a vertical reference (plumb line or door frame) allows the telehealth clinician to visually confirm inferior rib descent during the exhale phase of ZOA repositioning.
Question 7: A PRC practitioner reviewing force plate data notices a patient's center of pressure (COP) path during gait consistently deviates to the right during the left loading response. This finding is MOST consistent with:
- Inadequate left hip abductor recruitment causing right COP shift during left stance (Correct answer)
- Bilateral symmetric hip flexion generating a centered COP trajectory
- Right tibial torsion causing medial COP shift on the right foot
- Left plantar fasciitis reducing left toe-off push
Correct answer: Inadequate left hip abductor recruitment causing right COP shift during left stance
Insufficient left hip abductor activity during left stance allows the pelvis to drop right (Trendelenburg), shifting COP rightward on force plate analysis.
PRC Technology & Digital Tools 3
Surface EMG is used during a PRI wall supported hip flexor stretch.
Which muscle activation sequence confirms the patient has achieved a posterior pelvic tilt without hip flexor dominance?