title: Intra-articular temperatures of the knee in sports - an in-vivo study of jogging and alpine skiing.
abstract: BACKGROUND
  Up to date, no information exists about the intra-articular temperature changes of the knee related to activity and ambient temperature.
  
  
  METHODS
  In 6 healthy males, a probe for intra-articular measurement was inserted into the notch of the right knee. Each subject was jogging on a treadmill in a closed room at 19 degrees C room temperature and skiing in a ski resort at -3 degrees C outside temperature for 60 minutes. In both conditions, temperatures were measured every fifteen minutes intra-articulary and at the skin surface of the knee. A possible influence on joint function and laxity was evaluated before and after activity. Statistical analysis of intra-articular and skin temperatures was done using nonparametric Wilcoxon's sign rank sum test and Mann-Whitney's-U-Test.
  
  
  RESULTS
  Median intra-articular temperatures increased from 31.4 degrees C before activity by 2.1 degrees C, 4 degrees C, 5.8 degrees C and 6.1 degrees C after 15, 30, 45 and 60 min of jogging (all p < or = 0.05). Median intra-articular temperatures dropped from 32.2 degrees C before activity by 0.5 degrees C, 1.9 degrees C, 3.6 degrees C and 1.1 degrees C after 15, 30, 45 and 60 min of skiing (all n.s.). After 60 minutes of skiing (jogging), the median intra-articular temperature was 19.6% (8.7%) higher than the skin surface temperature at the knee. Joint function and laxity appeared not to be different before and after activity within both groups.
  
  
  CONCLUSIONS
  This study demonstrates different changes of intra-articular and skin temperatures during sports in jogging and alpine skiing and suggests that changes are related to activity and ambient temperature.
authors.affiliation: Department of Orthopaedic Surgery, Phillips University, Marburg, Germany. becher.chris@web.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Becher
authors.forename: Jan
authors.initials: J
authors.lastname: Springer
authors.forename: Sven
authors.initials: S
authors.lastname: Feil
authors.forename: Guiliano
authors.initials: G
authors.lastname: Cerulli
authors.forename: Hans H
authors.initials: HH
authors.lastname: Paessler
mesh_terms: D000328:Adult; D001831:Body Temperature; D002358:Cartilage, Articular / Q000502:physiology*; D003081:Cold Climate; D005060:Europe; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007590:Jogging; D007593:Joint Instability; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D016059:Range of Motion, Articular; D012865:Skiing; D012881:Skin Temperature