Sprinting Flashcards
what is the degree of the legs in elite sprinters from a start position?
around 90 degrees in front lower leg, around 133 degrees in rear lower leg
what is the exit angle of the front lower leg extension (measured at knee) during block clearance?
about 160 degrees
what is the optimal length of touchdown of first step?
0.5m from the start line
what is the initial starting velocity of elite sprinters?
5m/s
during both the start clearance and initial steps of the acceleration, where should the recovery swing legs be?
low to the ground to a point where the toes are barely off the ground
what is the average stride rate of the second step in elite runners/ novice
elite= 5.26, novice= 3.45
why is stride length shorter in elite athletes than in novice
they need less flight time so that horizontal velocity is increased through more frequent ground contact times
early flight in maximum velocity sprinting consists of
eccentric hip flexion: decelerates backward rotation of thigh
eccentric knee extension: decelerates backward rotation of leg/foot
midflight of maximum velocity sprinting
concentric hip flexion: accelerates thigh forward
eccentric knee extension —> eccentric knee flexion
late flight
concentric hip extension: minimizes braking effect of foot strike
eccentric knee flexion: accelerates leg backward, limiting knee extension; stops before foot strike (aided by concentric knee flexion to minimize braking at touchdown)
Early support
continued concentric hip extension: minimizes braking effect of foot strike
Brief concentric knee flexion followed by eccentric hip extension: resists tendency of hip/ankle extension to hyperextend knee; absorbs landing shock
Eccentric plantar flexion: helps absorb shock and control forward rotation of tibia over ankle
Late support
eccentric hip flexion: decelerates backward thigh rotation; rotates trunk in preparation for forward takeoff
concentric knee extension: propels center of gravity forward
concentric plantar flexion: aids in propulsion
