Study of Local Cryotherapy Methods for the Knee Joint

Abstract

BACKGROUND: one of the promising methods for treating musculoskeletal disorders to alleviate symptoms and promote recovery is local cryotherapy. Proper control and regulation of the procedure enable safe interventions with predictable therapeutic effects for various locations. AIMS: identification of measurable physical criteria for the effectiveness of local cryotherapy and characteristics for dosing the procedure, comparison and analysis of the capabilities of various methods. MATERIALS AND METHODS: the experiment involved 16 volunteers who were randomized into four groups. The first and second groups underwent local cryotherapy using ice bags for 20 minutes with a cooling agent consisting of an ice with water mixture and a 23,1% sodium chloride solution. The third and fourth groups underwent nitrogen (for 3 minutes) and air (for 20 minutes) local cryotherapy, respectively. During the experiment, the skin temperature was measured using a temperature sensor and thermal imaging camera. RESULTS: the lowest value of the minimum final temperature was recorded after cooling with liquid nitrogen vapor and was equal to (0,88 1,75) ○C. The minimum area of the working area was (33,7 7,1) cm2. When cooled with an ice bag with water and ice, the most uniform distribution of the temperature field among the studied cases was observed with the highest values of the minimum final temperature (6,43 0,90) ○C and working zone area (135,2 34,6) cm2 among the investigated methods. CONCLUSIONS: the main physical criteria for the effectiveness of local cryotherapy are revealed temperature and dynamics of its changes on the surface of the object of exposure. A dosing characteristic the area of the working area was proposed and evaluated. This is the area where the accepted target temperature is achieved. The easiest to use and prepare are contact methods using ice bags. Air cooling in the studied mode is more easily tolerated by the subjects, and from the point of view of physical criteria, it is equivalent to contact methods. Cooling with nitrogen vapor leads to the fastest achievement of the target temperature on the surface and the least cooling of internal tissues.