1. Therapeutic Ultrasound
Sports Medicine
Therapeutic Ultrasound

2. Discussion Scenario
A high jumper from the track team has been experiencing R knee pain. She visited the doctor and brought back a note clearing her for activity. She also brought back a script for ultrasound treatments 3 times a week. She asks you what ultrasound is used for and why she needs to do it.
What would you tell the athlete?
Be prepared to share your responses.

3. Objectives Explain how ultrasound works
List the indications and contraindications for using ultrasound
Justify the need for an ultrasound treatment

4. Terminology
Therapeutic ultrasound – a modality using sound waves to penetrate tissues for healing; can be thermal or non- thermal.

5. Therapeutic Ultrasound
Ultrasound machine
Sound head

6. How Ultrasound Works
The ultrasound unit contains a generator, which provides an electrical current that is transmitted to a crystal located in the sound head.
The electrical current causes the crystal to vibrate, producing a high-frequency sound wave.
Humans can hear 18,000 – 20,000 Hz (cycles/second)
Ultrasound is either 1 million (1MHz) or 3 million (3MHz)
The high-frequency sound waves generate heat energy.

7. How Ultrasound Works (cont.)
The sound wave is absorbed by tissues with a high protein content (tendons, ligaments, joint capsules, and muscle).
The sound wave is poorly absorbed by bone tissue; the majority is reflected or refracted.

8. Ultrasound Parameters
Frequency: cycles per second (Hz)
1 MHz – heats tissues from 2 to 5 cm deep
3MHz – heats superficial tissues
Intensity: the amount of energy transferred to the tissues, expressed in W/cm² (ranges from 0.1 to 5.0 W/cm²)
Continuous or pulsed sound beam:
Continuous output produces thermal effects
Pulsed output produces mechanical effects for tissue healing

9. Ultrasound Parameters
Duty cycle: the amount of time the ultrasound is on
20% means it’s on 1 out of every 5 seconds
100% means it’s on continuously
Treatment area: should be about twice the size of the sound head
Treatment length: usually 5-10 minutes

10. Ultrasound Guidelines
A coupling agent is required to transmit the sound waves into the tissue (either cream, gel or water)
The sound head must be moved about 2-4 cm per second to prevent burning
Requires constant supervision by ATC

11. Indications for Ultrasound
Acute injuries (tissue healing, non-thermal effects)
Chronic injuries
Muscle strains
Ligament sprains
Muscle spasm
Tissue tightness
Scar tissue

12. Contraindications for Ultrasound
Areas with sensory or circulatory deficits
Over fractures or open growth plates
Over tumors
Over artificial joints
Over heart, eyes, brain, spinal cord
Over reproductive organs
Over abdomen during pregnancy
Over herniated discs
Acute injuries (in continuous heat setting)

13. Ultrasound can safely be used:
1. To shrink tumors 2. Over open growth plates 3. Over the brain or spinal cord 4. Over scar tissue 5. For acute injuries
1. Hand signals:
thumbs up or thumbs down to indicate agreement or disagreement
use fingers to indicate a number selection such as “Which is the correct solution one, two or three?”
teacher gives feedback to the students

14. Ultrasound can be used for all of the following except:
1. Ligament sprains 2. Acute injuries 3. Chronic injuries 4. Muscle tightness 5. Muscle spasms
1. Hand signals:
thumbs up or thumbs down to indicate agreement or disagreement
use fingers to indicate a number selection such as “Which is the correct solution one, two or three?”
teacher gives feedback to the students

15. Ultrasound is contraindicated in which area?
1. Heart 2. Brain 3. Eyes 4. Reproductive organs 5. All of the above
1. Hand signals:
thumbs up or thumbs down to indicate agreement or disagreement
use fingers to indicate a number selection such as “Which is the correct solution one, two or three?”
teacher gives feedback to the students

16. Sample Treatments* Condition Frequency Duty Cycle Deep muscle adhesion
1 MHz
100%
Deep bursitis
20-50%
Superficial scar
3 MHz
Superficial tendinitis

17. Ticket Out the Door
What is the therapeutic difference between continuous ultrasound and pulsed ultrasound?
What is the difference between using a frequency of 1 MHz and a frequency of 3 MHz?