title: Self-Reported Knee Symptoms Assessed by KOOS Questionnaire in Downhill Runners (Skyrunners).
abstract: BACKGROUND
  The knee is the weight-bearing joint most commonly associated with sports injuries, and therefore is most at risk of developing degenerative changes, including osteoarthritis. Skyrunners can be considered to be at risk of developing symptoms of post-traumatic osteoarthritis due to downhill running.
  
  
  OBJECTIVE
  The aim of this study was to analyze the health of the knee joints of a large group of these athletes via a specific self-report questionnaire.
  
  
  METHODS
  This study was carried out by asking the participants of seven official Skyraces (22.4±3.1 km length; 1596±393 m elevation) to fill out a questionnaire. Information regarding age, sex, downhill elevation (m) during training and competitions over the last month, and history of previous knee injury was also collected before the participants filled out the Knee injury and Osteoarthritis Outcome Score (KOOS), which is a reliable and validated instrument designed to assess patients' opinions about their knees and associated problems that can result in post-traumatic osteoarthritis. Athletes were divided into six age groups (from 17 to 70 years) and 12 groups based on the downhill gradient they had covered over the last month (from 1,000 to 40,000 m).
  
  
  RESULTS
  Six hundred twenty-one questionnaires were collected from 45% of the participants in the seven races. Multivariate analysis revealed that self-reported KOOS scores were unrelated to age, sex and monthly downhill gradient. Only 74 (12%) of the participants reported previous knee injuries. Significant differences in the five subscales of the KOOS were found between skyrunners with and without previous knee injuries (P<0.01).
  
  
  CONCLUSIONS
  In the studied population, regular training for downhill running and participation in Skyraces could not be considered risk factors for subjective knee symptoms. Skyrunners with self-reported histories of knee injuries scored worse on all five subscales of the KOOS.
authors.affiliation: Isokinetic Medical Group, Education and Research Department, Bologna, Italy; International Skyrunning Federation, Biella, Italy.
authors.forename: Giulio Sergio
authors.initials: GS
authors.lastname: Roi
authors.affiliation: Physical Medicine and Rehabilitation Unit, Scientific Institute of Lissone (Milan), Institute of Care and Research (IRCCS), Salvatore Maugeri Foundation IRCCS, Lissone, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Monticone
authors.affiliation: Isokinetic Medical Group, Education and Research Department, Bologna, Italy; International Skyrunning Federation, Biella, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Salvoni
authors.affiliation: Department of Computer Science, University of Milan, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Sassi
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Giampietro
authors.initials: G
authors.lastname: Alberti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D056352:Athletes; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology*; D007718:Knee Injuries / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D012420:Running / Q000502:physiology*; D057566:Self Report; D011795:Surveys and Questionnaires; D055815:Young Adult