Tony Parker's Knee Injury: Freak Accident?

Tony Parker is the point guard for the San Antonio Spurs. On May 4th, 2017 he went down with a knee injury that was later classified as a Quadriceps Tendon Rupture. Parker is now out for the rest of the 2017 NBA Finals. 

Was this injury a freak accident or expected? Lets take a closer look, but first lets start with the anatomy:

Figure 1

the Fundamentals...

The Knee Joint (Figure 1) consists of the femur, tibia and patella. The patella holds the largest articular cartilage on the under surface. The patella glides on the articular surface of the trochlear groove on the femur.

Figure 2

The Quadriceps consists of 4 important muscles, the vastus intermedius, vastus lateralis, vastus medialis, rectus femoris  (Figure 2). The rectus femoris originates at the hip (anterior inferior iliac spine), whereas the other muscles originate on the femur. The Quadriceps tendon contains portions of the vastus intermedius, vastus lateralis, vastus medialis, rectus femoris that blend together 3cm above the patella (1). They come together to form one tendon that incorporates into the base of the patella. The Patella tendon starts at the apex of the patella and inserts at the tibial tuberosity.

Now lets take a look at the bio-mechanics of the knee:

The function of the quadriceps is to help extend the knee when elevated and to help stabilize the joint when the foot is in contact with the ground.The patella is very odd in the way it articulates with the femur. When in extension the patella does not come in much contact with the trochlear groove. As the knee proceeds into greater degrees of flexion, the patella becomes in greater contact with the trochlea grove (Figure 3). According to review by Mike Reinold, the most area of contact between the patella and trochlea came at 90 degrees of knee flexion (2)

Figure 3
Source: Mike Reinold (2)

Figure 4. 

Source: Mike Reinold (2)

As we move through knee flexion, the quadriceps must eccentrically control the rate of knee flexion. This eccentric pull from the quadriceps and the patellar tendon anchoring the patella causes compressive forces on the patella (Figure 4).  At that 90 degrees of flexion the estimated force can be up to 6.5x body weight. Also according to Doron, at 90 degrees and greater the force at the quadriceps tendon is 30% great than that at the patallar tendon (1).

 

Lets take a look at the amount of force production with each activity by Mike Reinold. As you can see the greater amount of knee flexion creates greater amount of force through knee joint (Figure 5). 

Figure 5  Source: Mike Reinold (2)

Figure 5 

Source: Mike Reinold (2)

No injury goes UNNOTICEd... 

Lets talk about how the quadriceps can now tear and how it relates to Tony Parker. Lets start by taking a look at Tony Parker's injury history in the last 7 months. When looking at the history it is important to remember that the body is a chain. Pain, dysfunction, restriction at one point will impact other areas in the body.

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  • 3/15/17-(Back Injury)
  • 3/6/17- Returned from quadriceps pain Coach Popovich states “Parker did not have his legs tonight”
  • 2/28/17-(Ruled out due to Quadriceps Pain)
  • 1/19/17-(L Foot Pain)
  • 12/6/16-(Left Knee Injury (Left Game)
  • 12/5/16-(Bruised Quad (Played that day))
  • 12/2/16-(Knee Injury (Did not Play)
  • 11/12/16-(Right Knee Soreness)
  • 11/4/16-(Right Knee Soreness (Out for a week)

The quadriceps tendon is very strong and able to resist high amounts of stress. According to Doron, even when the tendon is under high stress there is usually tears/ruptures at other areas other than the quadrceps tendon (1). This means that in order for a quadriceps to rupture, it would require a weakened tendon. A weakened tendon can result from overuse of tendon. Also according to Mike Reinold, when having patellofemoral (knee) pain evidence shows it due to the surrounding soft tissue and neural adaptions not necessarily the patalla itself (2).

Now take a look at the video below. Start at 52sec-1:08.

Lets focus on how Parker's Left Leg Lands after the jump. Most often quadriceps tendon ruptures occur during an attempt to regain balance (1). The quadriceps, as we discussed above functions as a knee stabilizer. When attempting to regain balance the quadriceps tendon will rapidly contract (1). When the knee is in a semi-flexed position, we now understand that the quadriceps tendon will undergo a greater amount of force and tension. As you can see that seems exactly what happened to Parker. The amount of force at the musculotendonious junction combined with weakened tendon (possibly due to injury history, especially the last 7 months could have been the perfect formula for a Quadriceps Tendon Rupture. 

Was this a freak accident or did we see it coming?

Proper prevention begins with proper screening. Understanding your bodies bio-mechanics during athletic activity is the first step in minimizing injury risk. Also, understanding when your body is in pain is a signal to seek help or advice from a medical professional. For Tony Parker, this could have been analyzing his squat, split stance, landing mechanics, joint mobility assessment and more. If during these athletic activities he was applying a greater amount of force through the quadriceps and not using other musculature of the lower leg, that contributes to his injury risk. The fact that his injury was a quadriceps tendon rupture, based on the literature, it leads me to believe that this was not just a freak accident rather the "next step" to a long over-use style progression. 

Be safer than sorry, come in today!

Book an appointment today to understand your injury risk with a BodyTrack analysisAs a professional athlete, a recreational athlete or not an athlete at all it is important to understand what your body is telling you. Let Omega Sports and Recovery help you decipher if there are any limitations in your performance and body and lets get you to optimal function fast!

-Ribu

 

Source: 

1. Ilan D, Tejwani N, Keschner M, Leibman M. Quadriceps tendon rupture. Journal of American Academy of Orthopaedic Surgeons. 2003;11(3):192-200.

2. Reinold M. Biomechanics of patellofemoral rehabilitation. Journal Article Reviews. :https://mikereinold.com/biomechanics-of-patellofemoral/.