Ankle drill in running drills: trotting in tiny steps from the ankle, knee extended, short ground contact. Sequence, mistakes and what research can and cannot say.
The honest answer up front: in the ankle drill you trot in tiny steps at high frequency from the ankle, the toe barely leaves the ground, and the knee of the stance leg stays extended. That is how the Swiss Federal Office of Sport (BASPO) and Swiss Athletics describe it [1]. The goal according to the source: brake the landing movement and then push off strongly [1]. In plain words: your foot should spring like a rubber ball, not land like a stamp.
What is it for? The movement trains muscles, tendons and ligaments around the ankle [1] and is the base for all skippings. Does it make you measurably faster? There is no study for this exact exercise. What exists: in a measurement of 22 male recreational runners, a stiffer Achilles tendon at rest was linked to lower energy cost of running [3]. That is a correlation, not proof that the exercise makes the tendon stiffer. And a review lists greater leg stiffness as favorable for running economy but warns against a general ideal technique [4].
A quick framing: the exercise looks unspectacular but is an honest test for your foot muscles. People doing it for the first time often feel their calves after 20 meters. That is normal as long as it feels like work and not like pain.
How hard is it? You learn the movement in one session. Until it springs without thinking, it takes a few weeks of two to three repetitions before a run, in experience terms.
Stand upright and roll the feet alternately from ball to heel without moving forward. The movement comes from the ankle, not the knee. Milestone: you can roll for 20 seconds without the knee wobbling.
Now you trot forward in very small steps. The toe lifts as little as possible from the ground [1]. The torso stays upright.
The knee of the stance leg stays extended [1]. That forces the ankle to do the work. Imagine running over hot coals: ground contact should be short. Anchor: the foot taps the ground instead of standing on it.
When the movement is clean, you raise the frequency. BASPO names high frequency with small steps as the goal [1]. Keep the torso loose and your gaze calmly ahead.
As a progression you do the exercise backward or sideways [1]. Milestone: 20 to 30 meters forward with an even beat, then 2 to 3 repetitions [2]. The running drills take 10 to 20 minutes in total [2].
Film yourself from the side at ankle height. If you see hardly any air under the toe and the knee stays almost unchanged, you have understood the exercise. Then count how many ground contacts you manage in ten seconds and write the number down. After a week you know whether your beat is getting steadier.
Trotting in very small steps at high frequency from the ankle, with an extended stance-leg knee and a barely lifted toe [1].
BASPO advises building technique drills into every running session, 10 to 20 minutes, each exercise 2 to 3 times over 20 to 30 meters [2]. That is a recommendation, not a study result.
That is not proven. A measurement of 22 runners only showed that a stiffer Achilles tendon was linked to lower energy cost [3].
Early, right after the arm drill. The low and medium skippings and the high-knee run develop from it; BASPO lists them in that order [2].
Skipping Drill: Low and Medium Skips for Quick Feet