title: Effects of protocol step length on biomechanical measures in swimming.
abstract: BACKGROUND
  The assessment of energetic and mechanical parameters in swimming often requires the use of an intermittent incremental protocol, whose step lengths are corner stones for the efficiency of the evaluation procedures.
  
  
  OBJECTIVE
  To analyze changes in swimming kinematics and interlimb coordination behavior in 3 variants, with different step lengths, of an intermittent incremental protocol.
  
  
  METHODS
  Twenty-two male swimmers performed n×di variants of an intermittent and incremental protocol (n≤7; d1=200 m, d2=300 m, and d3=400 m). Swimmers were videotaped in the sagittal plane for 2-dimensional kinematical analysis using a dual-media setup. Video images were digitized with a motion-capture system. Parameters that were assessed included the stroke kinematics, the segmental and anatomical landmark kinematics, and interlimb coordination. Movement efficiency was also estimated.
  
  
  RESULTS
  There were no significant variations in any of the selected variables according to the step lengths. A high to very high relationship was observed between step lengths. The bias was much reduced and the 95%CI fairly tight.
  
  
  CONCLUSIONS
  Since there were no meaningful differences between the 3 protocol variants, the 1 with shortest step length (ie, 200 m) should be adopted for logistical reasons.
authors: Polytechnic Inst of Braganca, Braganca, Portugal.
authors: Tiago M
authors: TM
authors: Barbosa
authors: Kelly
authors: K
authors: de Jesus
authors: J Arturo
authors: JA
authors: Abraldes
authors: João
authors: J
authors: Ribeiro
authors: Pedro
authors: P
authors: Figueiredo
authors: João Paulo
authors: JP
authors: Vilas-Boas
authors: Ricardo J
authors: RJ
authors: Fernandes
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology; D001696:Biomechanical Phenomena; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D009048:Motor Skills / Q000502:physiology; D010806:Physical Education and Training / Q000379:methods*; D013550:Swimming / Q000502:physiology*; D013996:Time and Motion Studies; D055815:Young Adult