ATC Therapeutic Modalities 1 — Questions and Answers
Question 1: What is the primary thermal effect of continuous therapeutic ultrasound at 1 MHz?
- Decreased tissue extensibility
- Deep tissue heating (up to 5 cm) (Correct answer)
- Superficial tissue heating (1-2 cm)
- Increased inflammatory response
Correct answer: Deep tissue heating (up to 5 cm)
1 MHz ultrasound penetrates to depths of 3-5 cm, making it effective for deep tissue heating in muscles and joints.
Question 2: Which cryotherapy application is MOST appropriate during the acute phase of a muscle strain?
- Contrast bath
- Moist heat pack
- Ice massage (Correct answer)
- Paraffin bath
Correct answer: Ice massage
Ice massage is appropriate during the acute phase to reduce pain, swelling, and inflammation following a muscle strain.
Question 3: Transcutaneous electrical nerve stimulation (TENS) primarily reduces pain through which mechanism?
- Direct muscle contraction
- Gate control theory and endorphin release (Correct answer)
- Increased blood flow to damaged tissue
- Collagen remodeling
Correct answer: Gate control theory and endorphin release
TENS reduces pain primarily through the gate control theory by stimulating large-diameter afferent fibers and promoting endorphin release.
Question 4: When applying therapeutic ultrasound, what does the spatial average temporal average (SATA) intensity reflect?
- The depth of penetration into tissue
- The average power output over time and transducer area (Correct answer)
- The frequency of the ultrasound waves
- The maximum temperature achieved in tissue
Correct answer: The average power output over time and transducer area
SATA intensity represents the average power output averaged over both the transducer area and the total treatment time, including off times for pulsed modes.
Question 5: A 3 MHz ultrasound frequency is MOST appropriate for treating which tissue depth?
- Deep muscles (4-5 cm)
- Large joints such as the hip
- Superficial tissues (1-2 cm) (Correct answer)
- Bone surfaces only
Correct answer: Superficial tissues (1-2 cm)
3 MHz ultrasound is absorbed more rapidly and is effective for heating superficial tissues at 1-2 cm depth.
Question 6: Iontophoresis uses electrical current to drive which type of substance transdermally?
- Oxygen molecules
- Ionized medications (Correct answer)
- Collagen proteins
- Neutral saline solution
Correct answer: Ionized medications
Iontophoresis uses direct current to drive ionized medications through the skin into underlying tissues for localized drug delivery.
Question 7: Which of the following is an absolute contraindication for the use of electrical stimulation?
- Chronic pain management
- Muscle atrophy
- Cardiac pacemaker (Correct answer)
- Peripheral edema
Correct answer: Cardiac pacemaker
Electrical stimulation is absolutely contraindicated in patients with cardiac pacemakers due to the risk of interfering with pacemaker function.
ATC Therapeutic Modalities 1
What is the primary thermal effect of continuous therapeutic ultrasound at 1 MHz?