title: Military exercises, knee and ankle joint position sense, and injury in male conscripts: a pilot study.
abstract: BACKGROUND
  The high incidence of lower limb injuries associated with physical exercises in military conscripts suggests that fatigue may be a risk factor for injuries. Researchers have hypothesized that lower limb injuries may be related to altered ankle and knee joint position sense (JPS) due to fatigue.
  
  
  OBJECTIVE
  To evaluate if military exercises could alter JPS and to examine the possible relation of JPS to future lower extremity injuries in military service.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  A total of 50 male conscripts (age = 21.4 ± 2.3 years, height = 174.5 ± 6.4 cm, mass = 73.1 ± 6.3 kg) from a unique military base were recruited randomly. main outcome measure(s): Participants performed 8 weeks of physical activities at the beginning of a military course. In the first part of the study, we instructed participants to recognize predetermined positions before and after military exercises so we could examine the effects of military exercise on JPS. The averages of the absolute error and the variable error of 3 trials were recorded. We collected data on the frequency of lower extremity injuries over 8 weeks. Next, the participants were divided into 2 groups: injured and uninjured. Separate 2 × 2 × 2 (group-by-time-by-joint) mixed-model analyses of variance were used to determine main effects and interactions of these factors for each JPS measure. In the second part of the study, we examined whether the effects of fatigue on JPS were related to the development of injury during an 8-week training program. We calculated Hedges effect sizes for JPS changes postexercise in each group and compared change scores between groups.
  
  
  RESULTS
  We found group-by-time interactions for all JPS variables (F range = 2.86-4.05, P < .01). All participants showed increases in JPS errors postexercise (P < .01), but the injured group had greater changes for all the variables (P < .01).
  
  
  CONCLUSIONS
  Military conscripts who sustained lower extremity injuries during an 8-week military exercise program had greater loss of JPS acuity than conscripts who did not sustain injuries. The changes in JPS found after 1 bout of exercise may have predictive ability for future musculoskeletal injuries.
authors.affiliation: Physiotherapy Department, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran;
authors.forename: Farshid
authors.initials: F
authors.lastname: Mohammadi
authors.forename: Kamran
authors.initials: K
authors.lastname: Azma
authors.forename: Iman
authors.initials: I
authors.lastname: Naseh
authors.forename: Reza
authors.initials: R
authors.lastname: Emadifard
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Etemadi
mesh_terms: D000328:Adult; D016512:Ankle Injuries / Q000503:physiopathology*; D000843:Ankle Joint / Q000502:physiology; D015444:Exercise; D005221:Fatigue / Q000503:physiopathology*; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology*; D007719:Knee Joint / Q000502:physiology; D008297:Male; D008889:Military Personnel; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000502:physiology; D010865:Pilot Projects; D011434:Proprioception / Q000502:physiology*; D055815:Young Adult
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