Why is front crawl faster than back crawl? Kinematic differences between the two techniques during sprint swimming

Tomohiro Gonjo, Carla McCabe, Ricardo J. Fernandes , João Paulo Vilas-Boas, Ross Sanders

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The purpose of this study was to investigate why front crawl is faster than back crawl from a kinematic perspective. Ten male competitive swimmers volunteered to participate in this study. Each swimmer performed one 50 m front and back crawl trial at maximum speed, separated by at least one day. A space of 6 m length (X), 2.5 m height (Y), and 2 m width (Z) in the centre of a 25 m pool was recorded by four underwater and two above water digital video cameras and calibrated to enable calculation of three-dimensional (3D) coordinates of the digitised landmarks using the direct linear transformation method. One stroke cycle (defined as the duration between two-subsequent entries of a wrist into the water) was chosen from the videos and analysed for both techniques. Swimmers achieved faster centre of mass velocity toward the swimming direction in front than in back crawl (1.70±0.04 vs 1.54±0.06 m/s; p<0.01). There was no difference in stroke length between the two techniques (2.00±0.25 vs 2.07±0.17 m/cycle), while stroke frequency in front crawl was higher than that in back crawl (51.67±6.38 vs 44.81±4.68 cycles/min; p<0.01). Absolute duration of the release phase (from the last backward movement to the exit from the water of the wrist) and relative duration of the recovery phase were shorter in front than in back crawl (0.07±0.03 vs 0.26±0.08 s; p<0.01). In conclusion, front crawl was faster than back crawl because of its higher stroke frequency due to the shorter absolute duration of the release phase and relative duration of the recovery phase.
LanguageEnglish
Title of host publicationBMS
Publication statusAccepted/In press - 15 Jan 2018

Fingerprint

kinematics
water
video

Keywords

  • Front crawl
  • Back crawl
  • Kinematics
  • Stroke frequency

Cite this

Gonjo, T., McCabe, C., Fernandes , R. J., Vilas-Boas, J. P., & Sanders, R. (Accepted/In press). Why is front crawl faster than back crawl? Kinematic differences between the two techniques during sprint swimming. In BMS
Gonjo, Tomohiro ; McCabe, Carla ; Fernandes , Ricardo J. ; Vilas-Boas, João Paulo ; Sanders, Ross. / Why is front crawl faster than back crawl? Kinematic differences between the two techniques during sprint swimming. BMS. 2018.
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abstract = "The purpose of this study was to investigate why front crawl is faster than back crawl from a kinematic perspective. Ten male competitive swimmers volunteered to participate in this study. Each swimmer performed one 50 m front and back crawl trial at maximum speed, separated by at least one day. A space of 6 m length (X), 2.5 m height (Y), and 2 m width (Z) in the centre of a 25 m pool was recorded by four underwater and two above water digital video cameras and calibrated to enable calculation of three-dimensional (3D) coordinates of the digitised landmarks using the direct linear transformation method. One stroke cycle (defined as the duration between two-subsequent entries of a wrist into the water) was chosen from the videos and analysed for both techniques. Swimmers achieved faster centre of mass velocity toward the swimming direction in front than in back crawl (1.70±0.04 vs 1.54±0.06 m/s; p<0.01). There was no difference in stroke length between the two techniques (2.00±0.25 vs 2.07±0.17 m/cycle), while stroke frequency in front crawl was higher than that in back crawl (51.67±6.38 vs 44.81±4.68 cycles/min; p<0.01). Absolute duration of the release phase (from the last backward movement to the exit from the water of the wrist) and relative duration of the recovery phase were shorter in front than in back crawl (0.07±0.03 vs 0.26±0.08 s; p<0.01). In conclusion, front crawl was faster than back crawl because of its higher stroke frequency due to the shorter absolute duration of the release phase and relative duration of the recovery phase.",
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author = "Tomohiro Gonjo and Carla McCabe and Fernandes, {Ricardo J.} and Vilas-Boas, {Jo{\~a}o Paulo} and Ross Sanders",
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Why is front crawl faster than back crawl? Kinematic differences between the two techniques during sprint swimming. / Gonjo, Tomohiro; McCabe, Carla; Fernandes , Ricardo J.; Vilas-Boas, João Paulo ; Sanders, Ross.

BMS. 2018.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - Why is front crawl faster than back crawl? Kinematic differences between the two techniques during sprint swimming

AU - Gonjo, Tomohiro

AU - McCabe, Carla

AU - Fernandes , Ricardo J.

AU - Vilas-Boas, João Paulo

AU - Sanders, Ross

PY - 2018/1/15

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N2 - The purpose of this study was to investigate why front crawl is faster than back crawl from a kinematic perspective. Ten male competitive swimmers volunteered to participate in this study. Each swimmer performed one 50 m front and back crawl trial at maximum speed, separated by at least one day. A space of 6 m length (X), 2.5 m height (Y), and 2 m width (Z) in the centre of a 25 m pool was recorded by four underwater and two above water digital video cameras and calibrated to enable calculation of three-dimensional (3D) coordinates of the digitised landmarks using the direct linear transformation method. One stroke cycle (defined as the duration between two-subsequent entries of a wrist into the water) was chosen from the videos and analysed for both techniques. Swimmers achieved faster centre of mass velocity toward the swimming direction in front than in back crawl (1.70±0.04 vs 1.54±0.06 m/s; p<0.01). There was no difference in stroke length between the two techniques (2.00±0.25 vs 2.07±0.17 m/cycle), while stroke frequency in front crawl was higher than that in back crawl (51.67±6.38 vs 44.81±4.68 cycles/min; p<0.01). Absolute duration of the release phase (from the last backward movement to the exit from the water of the wrist) and relative duration of the recovery phase were shorter in front than in back crawl (0.07±0.03 vs 0.26±0.08 s; p<0.01). In conclusion, front crawl was faster than back crawl because of its higher stroke frequency due to the shorter absolute duration of the release phase and relative duration of the recovery phase.

AB - The purpose of this study was to investigate why front crawl is faster than back crawl from a kinematic perspective. Ten male competitive swimmers volunteered to participate in this study. Each swimmer performed one 50 m front and back crawl trial at maximum speed, separated by at least one day. A space of 6 m length (X), 2.5 m height (Y), and 2 m width (Z) in the centre of a 25 m pool was recorded by four underwater and two above water digital video cameras and calibrated to enable calculation of three-dimensional (3D) coordinates of the digitised landmarks using the direct linear transformation method. One stroke cycle (defined as the duration between two-subsequent entries of a wrist into the water) was chosen from the videos and analysed for both techniques. Swimmers achieved faster centre of mass velocity toward the swimming direction in front than in back crawl (1.70±0.04 vs 1.54±0.06 m/s; p<0.01). There was no difference in stroke length between the two techniques (2.00±0.25 vs 2.07±0.17 m/cycle), while stroke frequency in front crawl was higher than that in back crawl (51.67±6.38 vs 44.81±4.68 cycles/min; p<0.01). Absolute duration of the release phase (from the last backward movement to the exit from the water of the wrist) and relative duration of the recovery phase were shorter in front than in back crawl (0.07±0.03 vs 0.26±0.08 s; p<0.01). In conclusion, front crawl was faster than back crawl because of its higher stroke frequency due to the shorter absolute duration of the release phase and relative duration of the recovery phase.

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KW - Back crawl

KW - Kinematics

KW - Stroke frequency

M3 - Conference contribution

BT - BMS

ER -