Ancillary Materials
ANCILLARY MATERIALS
LESSON 2.
BEHIND THE STRIDE: FLEXION & EXTENSION
What is your body doing during a maximum-velocity sprint? Below are the fundamental movements of the flight and support phases.
KEY TERMS before we begin:
Flexion — decrease in the angle of a joint (or, the bending of a limb or joint)
Extension — increase in the angle of a joint (or, unbending of a limb or joint)
After the foot pushes off the ground, the hip goes through a concentric hip flexion, which in turn brings about knee flexion of the same leg to prepare for the next foot strike.
RIGHT LEG
1 ) concentric hip flexion: accelerates thigh forward
2 ) eccentric knee extension: decelerates backward rotation of leg/foot
3 ) dorsiflexion: aids in balance and prepares the foot for striking the ground forcefully
LEFT LEG
1 ) eccentric hip extension: decelerates backward thigh rotation; rotates trunk in preparation for forward takeoff
2 ) concentric knee extension: propels center of gravity forward
3 ) concentric plantarflexion: aids in propulsion
UPPER BODY
Arm swing balances leg swing; upper back and shoulder muscles help with stability.
LESSON 1.
KINETIC CHAIN: FOCUS RECOVERY POINTS
Your athletic body is a kinetic chain, a continuous linking of individual parts in motion: bones connected to tendons, connected to muscles, linking to joints, and so on from foot to head, all moving in a fluid, seamless motion.
When all of the pieces are healthy and strong, work is distributed evenly; if one piece of the chain is weak, another has to make up for that weakness and take on more of the workload.
Targeting these trigger points help maintain healthy muscles joints and prevent injury.