A Full Court Press: Overcoming In-Season Patella Tendinopathy
Patella tendinopathy is one of the more common injuries in the NBA. Players need strategies to manage this problem during the season because cutting back on court volume and intensity isn’t always an option.
In this series, I will discuss how I manage patella tendinopathy in-season.
When it comes to the patella tendon, I want to know the following:
- How are forces being directed through the tendon?
- Does the tendon have normal viscoelastic properties?
To answer the first question, we must know how the knee moves and examine the athletes center of gravity (COG).
We'll discuss viscoelastic properties in the next article.
Step 1: Restore Tibiofemoral Mechanics
The patella tendon (or ligament) forms a bone-to-bone connection between the patella and tibial tuberosity. It is tensioned when the knee flexes, such as when landing from a jump.
Therefore, when working with an athlete with patella tendon pain, checking knee range of motion is my first step. I will assess:
- Supine Knee Flexion (~140 deg)
- Tibial Rotation (~40-45 total rotation — internal and external)
The reason I look at both knee flexion and tibial rotation, is that the tibia internally rotation occurs during knee flexion (see the Knee chapter of Kinesiology of Musculoskeletal System by Neumann).
In weight bearing, the majority of tibial IR occurs in shallower degrees of knee flexion. Under normal conditions, this decreases the oblique orientation of the patella tendon as knee flexion increases. By 90 deg of knee bend, the patella tendon will form approximately a right angle relative to the tibia plateau:
I have found that a lot of athletes, will appear to have “full knee flexion” but lack the tibial rotation that is necessary for knee flexion to occur. In this case, the tibia will remain in relative external rotation in relation to the femur during knee flexion.
This can interfere with the normal twist of the patella tendon during knee flexion, overloading some areas of the tendon while simultaneously underloading others.
There are a few manual and non-manual techniques I will utilize to restore knee tibial internal rotation
From an exercise standpoint, I like to utilize isolate the movement and then integrate it into a movement that involves multiple joints.
Supine Band Resisted Knee Flexion-Extension
Don’t be fooled by this exercise. If you ever want to feel a VMO, this is it.
Step 2: Control Center of Gravity
After tibiofemoral mechanics are addressed, I will look at how the athlete manages their COG. This can be done with a simple movement such as a squat.
The red line represents COG.
The green dots are the axis of rotation for the hip and the knee.
The blue lines represent external joint moments, drawn from the force vector to the center of rotation.
An external moment or torque, is the product of the external force (in this case gravity) acting a distance from the center of rotation of a segment (see Kinesiology of the Musculoskeletal System by Neumann)
As you can see, shifting my weight forward increases knee torque (longer blue line), and shifting my weight towards my heels decreases knee torque (shorter blue line).
In NBA athletes, it is quite often to see a COG that is shifted forward. In a squat or a landing, this can be visually represented in a variety of ways.
One of the more common strategies is athletes flex their hips and turn the squat into more of a hinge. This redirects some of the ground reaction forces (GRF) away from the knee. It “achieves” the same outcome as shifting weight towards the heels.
This hip dominant pattern has been shown at higher speeds, as athletes with patella tendinopathy will land in more hip flexion.
However, the technical requirements constrain the athlete from always utilizing a hip flexed strategy. How many rebounds are you going to get looking at the ground?
Image from Wikipedia
A forward COG then forces the athlete into a knee bent position they cannot attain. Areas of the tendon that have been stress shielded are overloaded and problems ensue.
Increasing the capacity of the tendon itself to handle these loads is a necessary step, but this can take time. In-season in the NBA demand more rapid solutions.
Addressing COG can provide the athlete with an alternative movement strategy to decrease load going through the knee.
I typically seek out symptom-free exercises that teach the athlete to shift their COG posteriorly without significant compensation (trunk flexion as an example).
There are countless exercises that could be used here. The principle is to begin in more constrained and gravity-reduced positions. Load can be progressed from there. Here are three examples:
As the athlete progresses, we increase velocity of the movement. These movements can be used as preparatory activities before the athlete is on the court. Here are two examples:
In part two of Managing In-Season Patella Tendinopathy, we'll examine strategies to aimed at improving patella tendon behavior.