Plyometric ankle jumps, also called “ankling” are designed to increase strength in the muscles of the anterior shin, minimize ground contact time and activate the stretch reflex in the muscles of the calf and ankle to increase strength, speed and power when performing linear and lateral movements. Because we are told to land on the ball of the foot when running, many runners mistakenly believe that they should land on the forefoot and then let the heel drop down, i.e., land and sink. The key to quick, powerful strides comes before foot contact, not after. Research shows that the fastest runners dorsiflex the foot prior to ground contact and then drive it down to push the body forward. Dorsiflexing the foot prior to contact produces an active, eccentric stretch in the muscles of the posterior calf which, in turn, activates the stretch reflex, resulting in a quicker more forceful push-off at ground contact. Dorsiflexing the foot also puts the ankle joint in the most stable anatomical position from which to exert force.
Beginners should start with a stepping down motion. First, lift (dorsiflex) the right foot and then step (push) down with enough force to lift the entire body up off the ground. Immediately repeat with the left foot. Continue alternating the feet in a rhythmic manner and gradually pick up the pace to increase the elastic response in the ankles.
When you can keep a high cadence with good form, jump off both feet at the same time. Keep the core tight and the trunk erect. Jump straight up using only the reactive strength of the calves and make sure that you apply enough force to lift the entire body off the ground on each push. When performed correctly, an observer should be able to see completely under each foot before and after foot contact. Dorsiflex the feet and pull the toes up on the way up and forcefully extend the ankles before ground contact. Push the balls of the feet into the ground explosively and bounce up quickly without bending the knees. Keep the core tight, trunk erect, arms out straight from the chest and legs straight throughout the drill. Be quick off the ground and minimize ground contact time.
Start with 2 sets of 8 reps and gradually build to 3 sets of 25. Hold a 6-10 pound MD ball at arm’s length to increase resistance, engage the core and help ensure that the body remains in an upright position. See the video, Landow – Plyometric Ankle Jumps for Reactive Calf Strength, for a demonstration of how to perform the drill.
Loren Landow, CSCS-D, USAW, MAT, NASM, is Director of Sports Performance, Steadman Hawkins Clinic – Denver. http://www.speedandagilitycoach.com/