Getting really strong in the weight room and being able to run fast in a straight line mean nothing if that doesn’t transfer over to game day performance.
Nobody wants to be a combine warrior, but be a liability when the game comes around.
If we really want to maximize an athlete’s potential, we need to maximize their agility training.
What is agility?
Agility is best defined as the ability to change direction and move in a manner that is optimal for the current environment.
Agility is a specific skill that needs to be trained with the context of the situation you want to use it in.
Every team sport requires the ability to recognize and react to stimuli.
A volleyball defensive specialist who is able to recognize where the ball is going to be hit at and then get her body over there to record the dig, a point guard driving up the court and putting his foot in the ground to hit the step back, and a defensive back stopping and starting with a receiver in man coverage all look very different, but they’re all under the umbrella of agility.
When we break it down, agility has three crucial components:
1) the ability to change direction or movement patterns
2) the ability to recognize and react to the appropriate environmental stimuli
3) the ability to move in a multi-planar manner (sprint, shuffle, side-run, backpedal, etc.).
To train agility then, we must increase your ability to absorb and redirect force in the right direction, enhance your ability to cognitively recognize the appropriate environmental cues to react to, and train the multi-planar movement patterns we want you to be able to express.
Here we’re going to focus on change of direction. Later, we’ll address the cognitive component that turns change of direction work into true agility.
Change of Direction
Change of direction (COD) is the act of stopping and starting that we traditionally think of with agility.
COD occurs in three phases: absorption, redirection, and projection.
The goal is to minimize the time and number of steps needed to accomplish each phase. These phases can occur in distinct steps, but it is ideal to be able to accomplish them simultaneously.
Absorption
The absorption phase is where your previous momentum is stopped.
Your momentum is equal to your mass (weight) multiplied by your velocity (speed).
In order to stop that momentum, an impulse equal to that momentum needs to be applied to the ground in the direction that they were going, so that the ground reaction force may be in the opposite direction and stop them (Newton’s 3rd Law).
Impulse is equal to force multiplied by time, so if you’re not able to produce enough force and apply it in the correct direction, it will take you more time to stop your momentum.
This is why young, untrained athletes need many steps to stop themselves from high speed sprints, while elite athletes can do it in very few.
Absorption force is produced through high-speed, eccentric muscle contractions.
For example, if you’re stopping from a linear sprint, the quadriceps are largely responsible for applying the braking force, as the knee angle goes from largely open to closed.
This is due to Newton’s 3rd Law. If an athlete wants to stop themselves from going forward, the force produced needs to be equivalent to going backward. A forward force vector must be put into the ground to receive a backwards ground reaction force vector.
Absorption will occur over several steps, but the more force you can put into the ground each step, the fewer steps you will need.
Direction of force application is critical for COD.
Fortunately, we can use the shin angle as a proxy to know what direction you’re applying force.
The shin is a representation of the line of force being applied to the ground.
If you want to propel and accelerate, then you should adopt a positive shin angle. This means going upward from the foot, the shin points in the direction you want to go.
If you want to absorb and decelerate, then you should adopt a negative shin angle. This means going upward from the foot, the shin points away from the direction she wants to go.
How do you get better at the absorption phase?
1) Get really strong on one leg (like split squats and reverse lunges). Specifically, the eccentric phase of these lifts. Performing them with a negative, neutral, and positive shin angle allows you to get strong in positions specific to change of direction.
2) Learn how to control your center of mass with pre-planned cone drills. The higher your center of mass is, the harder it is to stop. Learning how to lower it while you’re working at slower speeds and not reacting to anything can help teach your body how to get into the right positions.
Redirection
The redirection phase is the process of realigning the body segments to set up propulsion in the direction you want to go.
The goal is to minimize the time needed for redirection, so it is advantageous to merge this phase with the other two as much as possible to improve efficiency.
While the shins are representative of the angle of force application, the orientation of the pelvis sets the stage for the direction of movement.
The old adage stating “you can’t go anywhere without your hips” remains true.
When transitioning, the pelvis must reorient to the desired direction to allow the shanks to apply the appropriate force vector.
Therefore, it serves well to ensure that you have adequate hip mobility (especially in the transverse plane- hip rotation) and use footwork that optimizes pelvic reorientation.
For example, having adequate femoroacetabular external rotation allows you to plant the whole foot in the ground (T-Step) while keeping the pelvis oriented in the desired direction.
Pelvic reorientation occurs during both ground contact and flight time.
Pelvic reorientation during flight time allows mobility restrictions to be less of a factor.
Elite movers will be able to reorient their pelvis 90 degrees per step.
The amount of pelvic reorientation is dictated by the preceding movement pattern plane of motion and the succeeding movement pattern plane of motion.
Typically (but not always), the projection force will be parallel (sagittal movement) or perpendicular (frontal movement) to the orientation pelvis, depending on the movement variation that you’re transitioning from and to.
Efficient transitions should be completed within 3 steps, regardless of the amount of reorientation that is required.
How do you get better at the redirection phase?
1) Optimize your hip rotation mobility. It is important to make sure that you know your anatomy and don’t crank into a bunch of hip internal rotation if you’re predisposed to hip impingement issues.
2) Learn how to redirect your pelvis quickly with pre-planned cone drills and multi-planar bounds.
Projection
The projection phase is where you accelerate out in the new direction.
This is characterized by violent, concentric contractions.
The athlete has adopted a positive shin angle during the redirect phase and applies high levels of force to the ground to take advantage of Newton’s 3rd Law and accelerate out quickly.
How do you get better at the projection phase?
1) Improve your sprint acceleration. Sled sprints, power skips for distance, and other acceleration drills pay dividends here.
2) Getting really strong on one leg (like split squats and reverse lunges). Specifically, the concentric phase of these lifts.
Change of direction alone isn’t enough
If you can’t change direction efficiently, you’ll never have elite agility.
However, pre-planned cone drills and having the capability for change of direction alone is not enough.
You need to be able to recognize and react appropriately in the right context.
That’s where perception-action coupling and the cognitive side of agility comes into play.
Stay tuned to learn how to make your agility actually translate to game day!
Best,
Zach
Dr. Zach Guiser, PT, DPT, CSCS