title: The effects of knee direction, physical activity and age on knee joint position sense.
abstract: BACKGROUND
  Previous research has suggested a decline in knee proprioception with age. Furthermore, regular participation in physical activity may improve proprioceptive ability. However, there is no large scale data on uninjured populations to confirm these theories. The aim of this study was to provide normative knee joint position data (JPS) from healthy participants aged 18-82years to evaluate the effects of age, physical activity and knee direction.
  
  
  METHODS
  A sample of 116 participants across five age groups was used. The main outcome measures were knee JPS absolute error scores into flexion and extension, Tegner activity levels and General Practitioner Physical Activity Questionnaire results.
  
  
  RESULTS
  Absolute error scores in to knee flexion were 3.6°, 3.9°, 3.5°, 3.7° and 3.1° and knee extension were 2.7°, 2.5°, 2.9°, 3.4° and 3.9° for ages 15-29, 30-44, 45-59, 60-74 and 75 years old respectively. Knee extension and flexion absolute error scores were significantly different when age group data were pooled. There was a significant effect of age and activity level on joint position sense into knee extension. Age and lower Tegner scores were also negatively correlated to joint position sense into knee extension.
  
  
  CONCLUSIONS
  The results provide some evidence for a decline in knee joint position sense with age. Further, active populations may have heightened static proprioception compared to inactive groups. Normative knee joint position sense data is provided and may be used by practitioners to identify patients with reduced proprioceptive ability.
authors.affiliation: Sport and Exercise Kinesiology, Sports Injury Research Group, Department of Sport & Physical Activity, Edge Hill University, Ormskirk L39 4QP, United Kingdom. Electronic address: Nicola.Relph@Edgehill.ac.uk.
authors.forename: Nicola
authors.initials: N
authors.lastname: Relph
authors.affiliation: Sports Rehabilitation, School of Health Sciences, Frederick Road Campus, University of Salford, Salford M6 6PU, United Kingdom. Electronic address: L.C.Herrington@Salford.ac.uk.
authors.forename: Lee
authors.initials: L
authors.lastname: Herrington
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D007719:Knee Joint / Q000503:physiopathology*; D065466:Lysholm Knee Score; D008297:Male; D008875:Middle Aged; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D055815:Young Adult
keywords: Age; Knee extension; Knee flexion; Physical activity; Proprioception