Is Plyometric Training Causing Knee Injuries?

Here’s What You Need To Know…

1. “Jumper’s Knee” is nothing new in the athletic population, but with the recent increases of knee related pain and dysfunction in an otherwise fit and healthy population, we are left with questions about some sports performance plyometric training methods and programs that have gained popularity over the past decade.

2. Flawed plyometric based training programs are not only ineffective from a performance enhancement standpoint, but could also be predisposing athletes to chronic and acute natured knee injuries.

3. Protecting your knees, and enhancing performance and function starts with fixing broken plyometric programming, but also taking into account the main biomechanical players in knee positioning and alignment.

4. The pelvis, femur, tibia, and the ankle complex all have the ability to alter knee mechanics and motion, especially in plyometrics. Here’s how we are going to train each one of these regions to help keep the athletic and fitness populations safe and injury free including video movement based tutorials and coaching notes for every exercise.

---

Ever Been Diagnosed With Jumper’s Knee ?

Maybe you have heard of jumper’s knee or patellar tendinitis? Both are very common diagnoses given to athletes or active individuals of all ages. The nickname “jumper’s knee” explains everything you need to know in the title about one of the possible causation factors. Plyometrics, and any sporting activity that involves frequent bouts of jumping or change of direction, inherently places you at a higher risk for developing this type of painful experience.

Before we start getting into the nitty gritty on how to correct patellar tendinitis, we need to talk about possible plyometric programing mistakes that contribute to the chronic development of jumper’s knee.

Is Your Plyometric Program Doing More Harm Than Good?

The adherence to a flawed plyometric program is simply going to predispose you to chronic and acutely natured injuries at the knee, and no amount of corrective exercises can undue bad programming.

It is important to realize that plyometric type movements, or any type of vertical jump or bounding activity for that matter, are a max effort and highly neuromuscularly demanding form of physical activity. For this reason, rest periods should be kept relatively high (2-3 minutes, possibly longer) between bouts of explosive plyometric movements.

To the same point based on neuromuscular responsiveness, repetitions should always be kept low (1-5 repetitions maximum generally) when programming plyometrics with the goal of enhancing athleticism and transference into sport specific settings.

Lastly, volume and the total number of sets performed are highly dependent on the time of year, especially in the athletic performance population. Keep sets in the 2-4 range if you are in-season or just starting back into your training program. If you have been working out for a while or are in the off-season, you can get away with 4-8 sets in most cases, dependent on the technical form and quality of the movements themselves.

Finally, max effort plyometric movements should NEVER be used as a conditioning tool. With the popularization of things like box jumps and burpees, which are indeed forms of plyometric training, into the fitness industry, this statement cannot be reiterated enough.

How To Correct Flawed Plyometric Programming

Now that we have that taken care of the basics of plyometric training and it’s variables, let’s get into how we can best prevent and correct these issues when they do arise.

Unfortunately for the patella, this structure is the most prominent and superficial part of the knee. As such, it usually takes the brunt of the criticism for causing knee related pain. However, if we take a deeper look into how the body operates, we understand that the patella really is just the result of underlying positional problems for the most part. Understand that the patella is just a sesamoid bone (free-floating) that rides on the groove of the femur as it fits down into the tibia to create leverage in the quad. Nothing more, nothing less.

The common analogy used is the patella being the “train” that rides on the “tracks” of the femur. If the femur or “track” is in a poor position, then the patella cannot run properly across its groove.

So how do we address the underlying “track” so that the knee can function from an optimal position, and then properly adjust its position depending on the task at hand?

The structures that influence position of the knee are the pelvis, femur, tibia, and the ankle complex. Below are ways we can influence position and variability of each of these four structures, and ways to implement movement remediations right away into your programming including video tutorials and coaching notes.

The Ability of The Pelvis To Rotate on The Femur

If you are an athlete, coach or physical therapist, we are all aware that a femur has rotational properties. But what is often forgotten is that the pelvis has the ability to rotate on top of the femur as well.

The ability to optimally rotate a pelvis on a femur goes a long way to aid in hip range of motion and create a stable platform for displaying power through the lower body. A med-ball rotational throw, when performed correctly, is a simple exercise to teach the pelvis to rotate on a femur while displaying athleticism. Remember, plyometric training can be completed with the upper body and core as well as the lower body.

Rotational Med-Ball Throws

Coaching Notes:

Drive off your outside leg to transfer force toward your inside leg. The “zipper” of your shorts should face the leg your trunk is rotating towards. Annihilate the wall with the ball and focus on horizontal rotational power and limiting the amount of deviation from this centralized position.

Controlling the Femur and Knee Positioning

Probably won’t catch anybody by surprise here, or maybe I will. If your athletes are unable to control the femur from caving inward while squatting or jumping, you have a problem that needs to be addressed immediately! This is known as a valgus knee position, and it’s simply one of the most pivotal positions we need to avoid to limit structural damage to the knee secondary to movement and training.

Front foot elevated split squat or retro lunges are generally a good place to start when there is pain present. This is because the athlete can perform the exercise with a vertical shin so less stress is placed through the patellar tendon complex.

Front Foot Elevated Split Squat

Coaching Notes:

Front foot elevated on a small platform. Keep shin vertical as you drop your hips down toward the ground and drive through your front foot to stand back up tall.

Dumbbell Reverse Lunge

Coaching Notes:

Take a large drop step behind you as you lunge. Keep shin vertical and knee tracking over your middle toe. Drive through the front leg to stand back up tall, and return to start position.

Assisted Lateral Tap Down

However, being able to allow the knee to flex and translate over the foot when squatting or jumping is paramount for any athlete. For this reason, as soon as tolerable we want to progress toward a lateral tap down exercise. In my opinion, this is the king of all exercises when it comes to displaying single leg control. Often you will see the athlete’s knee caving inward while performing this exercise, so starting this exercise out with some form of assist is often required in order for success.

Coaching Notes:

Keep your nose over your toes as you sit your butt back and squat down. Control your knee so it stays in line with your middle toe. The height of the box will be completely dependent on what the athlete can succeed with. In addition, a mirror may be beneficial for the athlete when they are first learning this exercise.

Lateral Tap Downs

Coaching Notes:

After the athlete can optimally control the knee overtop their middle toe with assist, then it is time to perform the exercise without assist. This will challenge proprioception and balance, thus making is more highly transferable as a movement into the field or court for athletes.

Tibial Rotation

The tibia is one structure that unfortunately many people forget about when it comes to optimizing lower extremity positioning and global health.

The position of the tibia will influence the patellar tendon as it inserts to the tibial tuberosity. If one is unable to vary this position, it will start to create a repetitive unwanted torque to the tendon, which can also lead to a pain response locally.

When the knee bends from an extended position, the tibia must internally rotate to unlock the knee from terminal extension. Often times in athletes that perform a lot of repetitions squatting or jumping, this ability becomes dysfunctional. Here is a self-assessment that anybody can easily do.

Patellar Tendinitis Tibial Internal Rotation Self-Assessment

Coaching Notes:

Again, you are looking for asymmetries here. Often, the side that is painful will demonstrate less range of motion or less fluidity with movement. If you notice a difference, here are a couple of exercises that may help restore this motion.

Tibial Internal Rotation Deficit Fix With Edge Mobility Band

Coaching Notes:

Grip your shin and calf with both hands. Twist the tissue and shin inward. Maintain this pressure as you rock your knee forward over your middle toe. Pick Up an Edge Mobility Band Here

Tibial Internal Rotation Deficit Active Rotation Fix

Coaching Notes:

Knee bent to 90 degrees. Pull your foot up towards your shin, and rotate the heel up toward the ceiling as you keep your knee on the ground.

Enhancing Tibial Internal Rotation with Taping

Coaching Notes:

One final suggestion is a taping technique to help restore position of the knee and tibia internal rotation. Often when you see the knee taped it is addressing the kneecap or patella. While these may help temporarily, they tend not to help correct the underlying issue. Again, we want to address the “track” not the “train”.

The tape that works best for this technique is Leukotape. I have found this technique to be far superior to many other techniques, as it essentially is aiding tibia internal rotation while creating relative femur external rotation.

The key point with any taping technique though is that it provides the individual with a window of opportunity to restore normal function. The athlete cannot rely on tape for the rest of their life. So while the tape can help, the athlete better be doing something to help keep the changes and make them lasting!

Ankle Mobility

Last, but not least, is the ankle joint. The ability for the knee to translate forward overtop the middle toe is essential for athletic and daily movements. If ankle mobility is limited, the body will try to pick up the motion elsewhere. Often the areas of increased stress will be at the knee and hip joints. There are endless ankle mobility exercises out there, but what I have found to be the simplest and most effective is a dynamic foot elevated stretch.

Three Way Ankle Mobility Drill

Coaching Notes:

This list is defiantly not all inclusive. However, introducing these techniques into your training can go along ways to keeping your knees happy. Remember the fastest way to regress is through injury, so train smart and be proactive in your training.

---

ABOUT THE AUTHOR

Dr. Greg Schaible is a physical therapist and strength coach specializing in athletic performance.  He attended The University of Findlay as a Student Athlete.  As an athlete he competed in both Indoor and Outdoor Track & Field where he earned honors as a 5x Division II All-American and a 6x Division II Academic All-American. In 2013 he completed Graduate School earning his Doctorate of Physical Therapy (DPT).  Greg is the owner of On Track PT and Performance. In addition to his rehabilitation services, Greg has a passion for sport specific youth athlete training. Follow On Track PT and Performance on Facebook at On Track Performance.