Last week’s blog dove into what deceleration is and why it is important. This week’s blog is going to dive into the, “Okay now we know deceleration is important, so what do we do about it?
People may think that deceleration only applies to sports that have an offense and defense. But this isn’t true! Even my pickleballers: you have to decelerate then cut laterally to whack the ball over the net. Or my track & field stars: you have to decelerate prior to jumping over that hurdle or throwing that javelin.
Let’s dive into how we can test, train, and monitor deceleration capabilities in our athletes!
How do we Test Deceleration?
Traditionally agility tests, such as the 5-0-5 test, measure an athlete’s acceleration and change of direction (COD) abilities. This is a great screen for athletes, as both COD and acceleration are crucial for sports. The 5-0-5 test is done on both sides, and thus, can tell us any see side-side differences in an athlete’s ability to accelerate and perform a 180 degree change of direction.
But in a common agility test, such as the 5-0-5 test, “only approximately 31% of the time is spent actually changing direction” (Nimphius et al. 2016). Additionally, athletes tend compensate after injury and “an athlete who is fast linearly may still perform well in a COD test, as their sprinting ability could mask any deficiencies in COD ability” (Nimphius et al. 2016).
A better way to measure an athlete’s deceleration and COD capability? Still performing this 5-0-5 test but now we simply compare it to a linear 10-15 m sprint. Take the difference between these two tests and you have what is known as the deceleration deficit, a more accurate measure of an athlete’s ability to change directions and decelerate.
This is a crucial aspect of sport that is often diminished after injury or time away from the field. Incorporating unplanned, uncontrolled training in which an athlete has to react to a stimulus helps to mimic game-like scenarios. Colored cones that an athlete has to sprint to on command or flashing lights that the athlete has to react to are examples of ways we can train reactive agility in the clinic.
A common way we test and train reactive strength is the drop jump test in which an athlete drops off of a box and jumps back up as quickly as possible. This can be done on one or two legs depending on the stage of rehab.
We won’t get too sciencey on you, but the drop jump incorporates the stretch shortening cycle (SSC), which is “a natural form of muscle function, which occurs when active muscle lengthening (eccentric) is immediately followed by active muscle shortening (concentric)” (Flanagan and Comyns 2008). The SSC is utilized hundreds, if not thousands, of times per game with an athlete not even realizing it!
How do we Train Deceleration?
Well, we do the dang thing. Okay, but in all seriousness, our training is almost identical to our testing. We test the drop jump to get some metrics. Then we’re going to break this motion into pieces based on what we find, train these pieces, then put it all back together and retest it throughout the course of rehab.
Our athletes are going to train deceleration at different speeds and with different contraction types. Deceleration training will be done single leg, both legs, laterally, backwards, and forwards.
Why is this important? Studies have shown that “players who ineffectively decelerate momentum prior to COD [change of direction] may experience increased knee joint mechanical loading during the final foot contact of COD” (McBurnie et al. 2022). Essentially, players who haven’t trained deceleration tend to decelerate more abruptly, more of a slamming of the brakes vs. the desired controlled braking. This abrubt declaration results in more load going through the knee, unpleasant for any knee, but especially those knees that are rehabbing and trying to return to sport.
Where as acceleration requires this “triple extension” of the hip, knee, and ankle joints, deceleraation requires “triple flexion” of the corresponding joints. This is why we hone into our athlete’s range of motion and tolerance to flexion angles during rehab because if an athlete is hesitant to do this flexion in a controlled, slow manner during rehab, you can bet they’re not going to execute it effectively at speed and on the field. This lack of flexion ends up putting more load through structures that weren’t intended to take this much load, such as the joint capsule and surrounding ligaments.
How do we Monitor Deceleration?
There are many ways we can monitor an athlete’s ability and capacity to decelerate, so below are just a couple of mechanisms:
Load Management + Gradual and Progressive exposure
Like many injuries, deceleration related injuries can be the result of doing too much too soon. Taking on loads that our bodies simply weren’t prepared for yet. Does this mean our bodies will never be able to do that task? No! It just means we have to gradually expose your body to the stimulus. This gradual expospure may look like doing some change of direction drills in a controlled environment like PT and monitoring your body’s response (fatigue, form, pain, and soreness) before ever performing change of direction tasks in an uncontrolled environment like the soccer field. This is also why your Made 2 Move therapist will constantly check in with you regarding pain, soreness, and fatigue.
Use of force plates to monitor forces and fatigue
Counter movement jumps, monitored using force plates and visual analysis, are a helpful tool to measure form breakdown and diminishing force output, secondary to fatigue. This helps us gradually expose athletes to load without overdoing it.
Form will breakdown as fatigue sets in. Your therapist will monitor your ability to decelerate by visually accessing your hesitancy in flexion, compensation patterns, overall fatigue, and form breakdown.
Deceleration should not be just slamming on the E-brake. Deceleration requires CONTROLLED braking, an athlete’s capacity to skillfully slow down their whole body’s momentum. Deceleration will still be abrupt, as this all happens in a fraction of a second, typically less than 50 ms (McBurnie et al. 2022), but you want to be able to control your body’s momentum as much as possible as you slow down.
At Made 2 Move, we teach and help you master skills like deceleration. We help players become more aware and more in control of what their bodies are capable of during their sport. Increasing this awareness helps mitigate some of the injuries that can result from a lack of coordination or strength during deceleration.
Interested in working with a therapist who will pay attention to all aspects of your sport? Reach out to email@example.com to set up an initial evaluation!