Changes of Intraarticular Temperature in the Knee Joint according to the Application Method of Cold Jet-stream

OBJECTIVE: To investigate the changes of intraarticular temperature in the knee according to the application methods of cold jet-stream and to find the more effective method which reduces the intraarticular temperature. METHOD: Fifteen healthy subjects were examined. We recorded both skin and intraarticular temperature of the knee for 120 minutes. We compared two different cooling methods using -30 degrees C cold jet-stream by CRAis(R) (Century, Korea). The first was the intermittent cold jet-stream application method (ICA) which applied cold jet-stream to the knee joint every other minute for 5 minutes and the second was the continuous cold jet-stream application method with infrared (CCAI) for 5 minutes. RESULTS: In ICA, the intraarticular temperature maximally dropped as 1.7+/-0.6 degrees C (p<0.01) and it took 28.7+/-18.9 minutes. Intraarticular temperature dropped 0.6+/-0.5 degrees C after 2 hour (p<0.05). In CCAI, the intraarticular temperature maximally dropped as 2.8+/-0.7 degrees C (p<0.01) and it took 38.0+/-24.6 minutes, intraarticular temperature after 2 hour dropped as 1.36+/-0.75 degrees C (p<0.05). According to the two methods, CCAI showed more reduction in the lowest and after 2 hour intraarticular temperature compared with ICA in the knee joint (p<0.05). CONCLUSION: CCAI is better for reducing the intraarticular temperature than ICA.

Change in Skin Temperature according to Distance of Spraying Cold-jet Stream

OBJECTIVE: To examine the effects of changing the distance of spraying cold-jet stream (CS) on pain threshold and skin temperature. METHOD: Twenty one volunteers were examined. -30 degrees C cold-air was applied from 5 cm and 10 cm away to the skin of the right wrist. The following parameters were taken to measure the efficiency of the application: the cooling time for the subject to express pain (1st period), the rewarming time for skin temperature to rise to 20 degrees C at room temperature (2nd period), the re-cooling time again (3rd period), 4th, 5th and 6th time again. RESULTS: Skin temperature that subjects expressed pain was significantly at 10 cm distance than 5 cm. The rewarming speed of skin temperature was slower and slower according to repeat cold-air therapy in two groups. But there is no difference of rewarming time between 10 cm distance and 5 cm. CONCLUSION: There was no difference in rewarming time between 10 cm and 5 cm, hence, applying CS from 5 cm distance for a short period of time would be the more efficient method in terms of time-saving.

The Effect of Infrared to Cold Pain in Cold-jet Stream Application at the Knee

OBJECTIVE: To investigate the efficacy of infrared for lengthening applying time of cold-jet stream therapy without cold pain. METHOD: Each of the two methods of cryotherapy, cold-jet stream (CS) and cold-jet stream combined with infrared therapy (CSCI), was applied to the medial aspect of 32 volunteers' knees. The first phase was the required time that skin was dropped to 10oC with CS/CSCI. The second phase was the time for rewarming to 20oC without CS/CSCI. The third phase was the required time that skin dropped to 10degrees C again with CS/CSCI. The fourth phase was the time for re-warming to 20oC again without CS/CSCI. RESULTS: The required time which cold pain appeared after CS/CSCI were 51.3 sec and 62.3 sec, respectively, with significance (p<0.01). In CS and CSCI, first phase was 71.6 sec and 90.7 sec, respectively, and third phase was 33.2 sec and 39.9 sec, respectively (p<0.01). At second and fourth phases, it took 46.9 sec and 56.6 sec in CS (p<0.01), and took 46.9 sec and 54.6 sec in CSCI (p<0.01). CONCLUSION: As compared with CS, CSCI delayed sensation time of cold pain and prolonged application time of CS at the knee.

The Skin Temperature Change of Cold-jet Stream with Infrared Combination Therapy on Buttock

OBJECTIVE: To investigate the changes of the intramuscular temperature on buttock according to the application methods of cold jet-stream and to find the more effective method which reduces the intramuscular temperature. METHOD: Twenty eight healthy volunteers were examined. Cold-jet stream (CS) was applied on buttock (5 cm below of iliac crest, surface of gluteus medius muscle). We measured the time that skin temperature fall from room temperature to 10 degrees C (first period), the time rewarmed from 10 degrees C to 20 degrees C (second period), the time fall again to 10 degrees C (third period) and the time rewarmed again to 20 degrees C (fourth period). Cold-jet stream with infrared combination (CSIC) therapy was performed with the same method. RESULTS: At the first and third cooling periods, It took longer in CSIC group than CS group to decrease skin temperature. At fourth period, It took longer in CSIC group than CS group to rewarm skin. In CS and CSIC groups, fourth period is longer than second period. CONCLUSION: It took longer in CSIC method than CS only to decrease skin temperature to 10degrees C. Rewarming speed of skin temperature was slower twice cold-jet stream applies than once. Rewarming speed of skin temperature was slower at old-jet stream and infrared combination therapy than cold-jet only.