NPTE-PT Equipment and Therapeutic Modalities 4 — Questions and Answers
Question 1: During lumbar mechanical traction, a patient reports increased lower extremity paresthesias bilaterally. The BEST immediate action is:
- Reduce traction force by 50% and continue
- Switch from intermittent to continuous mode
- Stop the traction immediately and reassess (Correct answer)
- Increase the traction force to overcome neural tension
Correct answer: Stop the traction immediately and reassess
Bilateral worsening neurological symptoms during traction may indicate increased spinal cord or cauda equina compromise, requiring immediate cessation.
Question 2: Which electrode configuration in electrical stimulation results in the deepest current penetration between electrodes?
- Monopolar — active electrode over target, dispersive electrode distant (Correct answer)
- Bipolar — both electrodes close together over the muscle
- Quadripolar — two channels with electrodes interleaved
- Monopolar — both electrodes adjacent to each other
Correct answer: Monopolar — active electrode over target, dispersive electrode distant
In monopolar configuration, current flows from the small active electrode through deep tissues to the large dispersive electrode placed at a distance, maximizing depth.
Question 3: A therapist is selecting a prosthetic foot component for a K3-level transtibial amputee who wants to return to jogging. Which foot is MOST appropriate?
- SACH (solid ankle cushion heel) foot
- Single-axis foot
- Energy-storing/returning carbon fiber foot (Correct answer)
- Multi-axial foot
Correct answer: Energy-storing/returning carbon fiber foot
Energy-storing and returning (ESR) carbon fiber feet store energy during loading and release it at push-off, enabling higher activity levels including jogging.
Question 4: Which parameter of therapeutic ultrasound should be INCREASED to treat a superficial scar (1 cm depth) and maximize tissue heating?
- Frequency from 1 MHz to 3 MHz (Correct answer)
- Duty cycle from 100% to pulsed 20%
- Frequency from 3 MHz to 1 MHz
- ERA from 5 cm² to 10 cm²
Correct answer: Frequency from 1 MHz to 3 MHz
3 MHz ultrasound absorbs more rapidly in superficial tissues (1–2 cm), producing more heat at that depth compared to 1 MHz.
Question 5: A patient using axillary crutches complains of tingling in the ring and little fingers. The MOST likely cause is:
- Excessive weight bearing through the axillary pad compressing the brachial plexus (Correct answer)
- Ulnar nerve compression from grip on the hand piece
- Median nerve compression at the wrist from the hand piece
- Radial nerve compression from the axillary pad
Correct answer: Excessive weight bearing through the axillary pad compressing the brachial plexus
Weight bearing through the axillary pad compresses the radial nerve or brachial plexus; however, the ring/little finger pattern specifically points to ulnar nerve or C8/T1 involvement from pad pressure.
Question 6: For a patient with lymphedema, which hydrotherapy approach is CONTRAINDICATED?
- Cool-water pool therapy for gentle exercise
- Contrast bath with alternating warm and cold
- Neutral warmth whirlpool for dependent extremity (Correct answer)
- Aquatic therapy in a controlled pool temperature
Correct answer: Neutral warmth whirlpool for dependent extremity
Warm whirlpool with dependent positioning increases hydrostatic pressure and vasodilation, worsening lymphatic congestion and edema.
Question 7: When fabricating a low-temperature thermoplastic orthosis, the material becomes too rigid before molding is complete. The MOST appropriate solution is:
- Apply a heat gun to the area that has hardened (Correct answer)
- Increase water bath temperature above the recommended range
- Discard and restart with a new piece of material
- Add padding to compensate for the poor fit
Correct answer: Apply a heat gun to the area that has hardened
A heat gun can selectively re-soften thermoplastic material to allow continued molding without overheating the entire piece or starting over.
NPTE-PT Equipment and Therapeutic Modalities 4
During lumbar mechanical traction, a patient reports increased lower extremity paresthesias bilaterally.
The BEST immediate action is: