Therapeutic Modalities Application Flashcards

A PT plans to use iontophoresis with dexamethasone to treat a patient with carpal tunnel syndrome. Dexamethasone is negatively charged; which electrode setup is correct?

Answer: Place dexamethasone under the cathode (negative electrode)

Like charges repel; negatively charged dexamethasone is driven into tissue when placed under the cathode (negative electrode).

Which ultrasound parameter should a PT DECREASE to minimize thermal effects while still promoting tissue healing in an acute inflammatory condition?

Answer: Duty cycle

Reducing duty cycle (using pulsed mode) minimizes thermal accumulation while preserving non-thermal mechanical effects like acoustic streaming.

A patient with a cardiac pacemaker presents for shoulder rehabilitation. Which modality is SAFE to apply to the ipsilateral shoulder?

Answer: Therapeutic ultrasound

Therapeutic ultrasound does not generate electrical current and does not interfere with pacemaker function when applied away from the chest.

When treating a patient with spasticity using cryotherapy, which effect on the muscle spindle explains the temporary reduction in tone?

Answer: Decreased afferent (Ia) firing from muscle spindle due to cooling

Cooling slows the firing rate of muscle spindle afferents (Ia fibers), temporarily reducing the excitatory drive and decreasing spastic tone.

Which type of electrical stimulation parameter is MOST appropriate for preventing disuse atrophy in a patient with an immobilized limb?

Answer: Neuromuscular electrical stimulation (NMES) with sufficient intensity to elicit a visible contraction

NMES at motor-level intensity produces muscle contractions that maintain muscle bulk and prevent disuse atrophy.

A PT treating a patient with open wounds over the medial knee should avoid which modality directly over the wound?

Answer: Continuous ultrasound

Continuous ultrasound over open wounds risks thermal injury to exposed tissue and is contraindicated; pulsed may be used cautiously per clinical guidelines.

For a patient with chronic venous insufficiency and lower extremity edema, which physical agent modality is MOST appropriate to assist fluid mobilization?

Answer: Intermittent pneumatic compression (IPC)

Intermittent pneumatic compression mechanically mobilizes interstitial fluid proximally, reducing edema associated with chronic venous insufficiency.