Knee hyperextension and delayed heel rise in an interesting sport, Racewalking.

If you have been in practice long enough, you should know by now that in order to truly help an athlete you have to know their sport, the subtleties and the specifics.  You have heard us talk about premature heel rise off an on for years. Today, you must consider the opposite, delayed heel rise and the bizarre loading responses that come into the kinetic chains from such a behavior.

Racewalking is a long-distance event requiring one foot to be in contact with the ground at all times. Stride length is thus reduced and so to achieve competitive speeds racewalkers must attain cadence rates comparable to those achieved by Olympic 800-meter runners for hours at a time. Most people cannot truly appreciate how fast these folks are going.

There are really only two rules that govern racewalking:

1-The first rules states that the athlete’s trailing foot’s toe cannot leave the ground until the heel of the leading foot has created contact. 

2-The second rule specifies that the supporting leg must straighten, essentially meaning knee extension (and for some, terminal extension, ie. negative 5-10 degrees !) from the point of contact with the ground and remain straightened until the body passes directly over it. Again, essentially meaning full range knee extension for the entire stance phase of gait (early, mid and late midstance phases). 

Delated heel rise ?

Clearly some folks are going to take knee extension a little more literally. Look at the fella in the red and yellow. Can you say knee HYPER extension ? This is right knee anteriormeniscofemoral impingement looming on the horizon, this is an anterior compression overload phenomenon via the quadriceps. This is often met in this sport with the delayed heel rise that the sport seems to often drive. Prolonging the foot ground contact phase, attempting to abide by Rule#2, “the support  leg must straighten”, can lead to knee hyperextension if one is not careful. This will put a longer stretch load into the achilles and posterior compartment mechanism and this prolonged stretch-contract load can eventually lead to local pathology let alone in combination with the anterior knee compression we just eluded to. These folks will also be at risk for more anterior pelvic tilt, distraction of the anterior hip capsule-labral interval, unique hip extension and gluteal integration, and even possibly altered hip extension motor patterning driving abnormal loads into the hamstrings and low back.  Just imagine the changes in the hip flexor strategies in this scenario. 

To help your athletes, know their sport, know your normal biomechanics and know the pathologies when the rules of clean biomechanics are broken.

Today, on Rewind Friday, we will repost a more in-depth, with video, piece we did a few years ago on Race Walking. You may learn more about normal and abnormal gait than you think, today we translate some of the rules of the sport of race walking into deeper thoughts on gait mechanics.

Here is the link to our more in-depth video assessment and dialogue on the fascinating sport of race walking. If you have never truly looked at this sport before, you should enjoy this Rewind Post. (link).

- Dr. Shawn Allen

Too much potential gait pathology all in one sport ? Racewalking … . 

Do not underestimate this title, you may learn more about normal running form from today’s blog post than you think.

 

For the best clips start watching at the 4:15 mark. 

The sport of race walking is an interesting one to say the least.  We had the pleasure for years of treating and working closely with one of our countries best race walkers and she taught me so much, not only about the sport but about the strange mechanics of the sport and the functional pathologies the sport drives from its unique requirements driving abnormal gait mechanics on each step.

Racewalking is a long-distance event requiring one foot to be in contact with the ground at all times (and a couple of other unique and wacky rules that we will discuss in a moment). Stride length is thus reduced and so to achieve competitive speeds racewalkers must attain cadence rates comparable to those achieved by Olympic 800-meter runners for hours at a time. Most people cannot truly appreciate how fast these folks are going, most folks will have to move into at the very least a gentle run to keep up with these folks.

 

There are really only two rules that govern racewalking:

1-The first rules states that the athlete’s trailing foot’s toe cannot leave the ground until the heel of the leading foot has created contact. The rule violation is known as "loss of contact". 

2-The second rule specifies that the supporting leg must straighten, essentially meaning knee extension (and for some, terminal extension, ie. negative 5-10 degrees !) from the point of contact with the ground and remain straightened until the body passes directly over it. Again, essentially meaning full range knee extension for the entire stance phase of gait (early, mid and late midstance phases). For those who do not study the details of gait, this may not seem like a huge issue, but it is because full lockout really never occurs in either walking or running.  And there is nothing like impacting a joint in full extension lock and heavy heel strike to take away all of the natural shock absorbing mechanisms of the lower limb. (watch the video at the 4:30 mark, Dang ! the dude in the red looks like his knees are going to fold backward there is so my knee extension !) There is some great slow motion technique breakdown at the 6:28 minute mark of the video. 

In getting around these 2 major rules:

- the hips must rotate a tremendous amount, with full pelvis rotation, to prevent the frontal plane pelvis motion which would be a loss of sagittal power. This produces the visually painful waddle that is classic to the sport.

- the arms are used aggressively to generate power and to help the lower limbs move through the cycle because of the unnaturally apropulsive nature of the overall technique. The arms also often move excessively into the frontal plane since they mirror the lower limb

- excessive lateral heel strike quite often ensues help keep the knee extended and in an attempt to keep the foot on the ground longer, to avoid getting red carded. 

- there is plenty of cross over gait and severe lack of ankle dorsiflexion for everyone to observe, both of these components combined with the above characteristics give the “Close to the ground” appearance that is attempted by all racewalkers.

- want to see some seriously gut wrenching biomechanics, forward the video to the 7:55 mark. Tell us that won’t cause problems down the road !

Breaking the Rules:

The rules are entirely subjective and enforced by real-time human eye (not video) judges along the course (3 red card violations render an event disqualification). Interestingly, and we have seen this first hand, athletes quite regularly lose contact (meaning initiating a float phase, which is what dictates the difference between running and racewalking) for a few milliseconds per stride.  This float can be detected on film/video which can be caught on film, but such a short flight phase is said to be undetectable to the human eye. Disqualifications (losing contact or bent knee) are routine at the elite level as evidenced by the famous 2000 Summer Olympic case of Jane Saville who was disqualified on her way to a gold medal.

Racewalking … .  a highly technical sport, more so than running.  If you ever get a chance to see someone do this sport first hand, it is truly engaging to a gait geek. Lots of eye candy, gait geek eye candy that is !

Shawn and Ivo… … the gait guys.