ABSTRACT
OBJECTIVE: To determine the effect of moderate-intensity walking on rewarming of the triceps surae muscle group after a 20-minute application of a crushed-ice pack. DESIGN AND SETTING: Subjects were randomly assigned to either the ice-rest or the ice-exercise group. All subjects were treated on the left calf for 20 minutes with a 1.8-kg ice pack. The ice-exercise group walked on a treadmill at 5.63 km/h for 10 minutes and then assumed a prone position on an examining table for 20 minutes. The ice-rest group assumed a prone position on an examining table for 30 minutes after the cryotherapy treatment. SUBJECTS: Twenty-eight (19 men and 9 women) college-student volunteers. MEASUREMENTS: Intramuscular temperature was recorded at 10-second intervals for 50 minutes at 1 cm below the subcutaneous fat with a thermocouple implanted via a 21-gauge sterile hypodermic needle. Differences were analyzed within and between groups at pretreatment (T(0)), the end of the ice treatment (T(20)), 11 minutes after the end of ice treatment (T(31)), and 30 minutes posttreatment (T(50)). RESULTS: We found no differences at T(0) and T(20) but significant differences at T(31) and T(50). At T(31), the ice-exercise group was only 0.61 degrees C colder than at pretreatment levels, while the ice-rest group was 8.05 degrees C colder. By T(50), the temperatures were 0.93 degrees C and 6.95 degrees C colder, respectively, than at pretreatment levels. CONCLUSION: Moderate walking significantly enhanced rewarming of the triceps surae.
ABSTRACT
OBJECTIVE: To determine serum levels of dexamethasone at several intervals after administration of Decadron (dexamethasone sodium phosphate) phonophoresis. DESIGN AND SETTING: This study was designed as a 2-factor analysis of variance with repeated measures on 1 factor (blood draws). Independent variables were group (gel/sham, gel/ ultrasound, dexamethasone/sham, dexamethasone/ultrasound) and blood draws (pretreatment, posttreatment, 15 minutes, and 30 minutes). The dependent variable was the serum level of dexamethasone. SUBJECTS: Forty healthy college students (21 males, 19 females; mean age = 22 +/- 1.3 years) with no known drug allergies or current medication use were randomly assigned to 1 of 4 treatment groups. The treatment site was the left forearm. MEASUREMENTS: After the pretreatment blood draw, a 10- minute ultrasound treatment was administered, followed by a posttreatment blood draw. Two additional blood draws followed at 15-minute intervals. A total of 4 serum samples (5 cc each) from each subject were centrifuged, and the pipetted serum was frozen for later analysis by double antibody radioimmunoassay. RESULTS: No significant amounts of serum dexamethasone were detected in 12 consecutive samples. Testing of additional samples was, therefore, discontinued. CONCLUSIONS: Decadron phonophoresis as used in this experiment did not result in detectable serum levels of dexamethasone. More study is needed to validate the efficacy of Decadron phonophoresis on serum dexamethasone levels.
ABSTRACT
OBJECTIVE: To determine the rate and magnitude of temperature change in response to ultrasound in human patellar tendon for two treatment sizes. DESIGN AND SETTING: A thermistor was inserted into the medial aspect of each subject's right patellar tendon, and the baseline temperature was recorded. Using stratified random sampling and using a transducer head with an effective radiating area (ERA) of 4.5 cm(2), we had eight subjects each undergo either the 2-or 4-ERA ultrasound treatment first. Each subject received a 3-MHz continuous ultrasound treatment at 1 W/cm(2) for both the 2-and 4-ERA treatment sizes. SUBJECTS: Sixteen subjects (8 males, 21.3 +/- 1.9 years, and 8 females, 21.0 +/- 2.8 years) participated. MEASUREMENTS: We moved the sound head at a speed of 2 to 3 cm/sec while recording the tendon temperature every 30 seconds during, and for 20 minutes after, the 4-minute treatment. Twenty minutes after the treatment, we applied the second treatment to the other ERA treatment size. RESULTS: At the end of the treatment, the mean temperature increase was significantly different (P = .006) between treatment sizes (8.3 degrees C +/- 1.7 degrees C (2 x ERA) and 5.0 degrees C +/- 1.0 degrees C (4 x ERA)). The rate of increase was also significantly different (P < .001). The heating rate per minute for the 2-ERA treatment was 2.1 degrees C +/- 0.4 degrees C and 1.3 degrees C +/- 0.3 degrees C for the 4-ERA treatment. There was a significant difference in the cooling between treatment sizes (P = .001). The rate of temperature decrease between treatment sizes was significantly different only during the first 5-minute interval post-treatment. CONCLUSION: Three-megahertz ultrasound at an intensity of 1 W/cm(2) significantly increased patellar tendon temperature at both 2 and 4 x ERA, but our results confirm that the 2-ERA treatment size provided higher and longer heating than the 4-ERA treatment size.
