Monday, January 04, 2010
Loading And Tensioning: Part II
As promised here is the second installment. You may need to review part I.
As we begin to view our athletic movements and bio-mechanics through the filter of soft-tissue load-ordering, common athletic injuries and sports-related body problems become much easier to understand. Let's use the classic sport's medicine diagnosis "jumper's knee," as an example.
Jumper's knee is generic term for some kind of tendon problem (tendonopathy-itis/osis) of the patellar tendon below the knee cap (which is technically a ligament I know.) This kind of problem most often expresses itself as a painful knee cap in jumping related movements like the push-press in the image above.
Let's take a closer look at what's going on at the knee. It order for Bernard to keep his torso upright and his "jump" moving straight up and down, he clearly has to bend more at the knee and not the hip (hip flexion will tilt his torso forward and he'll end up jumping off axis and out of plane, or squatting). But because the knee and quadriceps are loaded first (they typically move first), subsequent loading of the hips and posterior chain will only increase the load forces at the knee cap. Now imagine a high level athlete with tight quads and tight anterior hips (gasp, impossible) and you've got additional freakish system tensioners on an already pre-loaded/pre-biased tendon system. You do have to keep the torso upright after all (so hey, burn those patellas). Compounding the forces at the knee is the anterior translation (forward movement) of the knee out over the foot as the athlete dips lower and nears peak compression. This translational tendon loading can exponentially increase the forces at the knee cap.
No wonder your knees are sometimes sore after a crap-ton of push-presses!
Clearly, cueing athletes to turn our their feet a little, stretch their quads, get adequate warm up, and compress to their heels, will significantly attenuate the forces on the tendon at the distal knee cap. You need to get as much hip loaded as is possible without inclinating at the torso. But now, you understand how and why these tendon puppies get hot.
So don't jump the barbell up from some knee forward, dog-poo, weak-ass(literally), muted-hip (CF talk for weak), position and wonder why your knees are all uppity.
You loaded 'em first, then jumped. And where's the butt in that?
Stay tuned...Part III
at 9:42 PM