A Review: The Biomechanics of a High Jumper's Rotation on Take-off and Bar Clearance

This article in Modern Athlete and Coach, by Pat Reid, has greatly enriched my understanding of the high jump. The focus of this article is the takeoff position and flight over the bar. A major theme is how the athlete can effect the parabolic path and rotation over the bar at the moment of takeoff. As I discuss this article I want to focus on the visual cues and descriptions of appropriate technique rather than the biomechanics aspect. Biomechanics are important for a coach to understand, but most athletes don't respond to terms such as tangential force and angular momentum.

Takeoff Takeaways:

·         Plant leg is almost completely locked out with minimal bend in the knee

o    The athlete should run with the amount of speed he or she can control without buckling plant leg

o    Straight leg creates tension and helps with rebound off the ground

o    Leg is pre-tensed before contact

·         Angle of last two steps toward back corner of the pit

o    Not parallel to bar!

o    25 degree angle from bar

·         Free leg knee drives fast and powerfully in a vertical direction

o    Don't twist knee away from bar, twisting knee away causes loss in vertical lift

·         Upper body should be twisted at a 90 degree angle away from the bar at takeoff

o    This coil away from the bar is what creates rotation over the bar

o    Reid describes how a diver off of a diving board creates flipping rotation by twisting the upper body when leaving the board not by twisting the legs

Flight:

·         Leave free knee out wide to slow lateral rotation

o    Keeps athlete parallel over the bar

o    You often see knees apart as the athlete travels over the bar

·         Consciously pull trial leg to butt under the bar

o    Causes hips to rise and speeds up rotation around the bar

Do Not:

·         Jumper should not lean in with arm, head or shoulder before leaving the ground

o    This causes peak of parabolic path to be beyond the bar rather than on top of the bar

o    Often hear coach's say "Stay away from the bar."

·         Don't reach with the arms at takeoff

o    Keep them within the cylinder of the body

The final trick, which is not discussed in this article, is teaching the athlete to perform these technical movements.

-John Egan

Reid, Pat, Modern Athlete & Coach Oct2009, Vol. 47 Issue 4, p20