Leg-length discrepancy and stance.

Is it common for fitters to check for leg length discrepancy?  

When I get fitted, I usually require a 1.5 degree cant out on the right foot due to a knock-kneed stance. Recently, having been intoduced to rollerbalding, I discovered through accident that inserting a 5mm shim inside the left boot immediately negated the effect of the knock kneed stance when flexing. Both knees flexed paralell to the shins with a natural feel to the stance, without any bow inwards into a knock-kneed stance.  Without the shim on the left foot, I go back to the inward knock-kneed profile on the right foot.

Given that over 50% of people have a leg length discrepancy of at least 1/4 of an inch, this probably could be something that can assists a skier in providing a neutral stance, I would think? Or is this something best left allone?  I am going to play around with this. I have a pair of un-used Head Mojo boots that I am going to have a 5mm shim installed on the left foot to see if I get the same effect I did when on the rollerblades.  

I experimented a bit with shims under the boot on the kitchen floor. I took a couple 3mm bontenx shims and tried flexing with them under the left boot while in the Mojo's. Like the rollerblades, the knock-kneed stance dissapeared entirely when flexing. Although I haven't used this setup on the snow, the stance felt strangely more natural than when in my boots that are canted out 1.5 degrees on the sole. In short, the canted boots feel like my foot is being put into a neutral position wheras with the shim only, it feels like both feet are where they should be.

Hi Mojo,

     Fixing a LLD should be the first line of approach in stance balancing(although LLD needs a RX in order to be adjusted)  if left unattended and canted for, other alignment issues will show up in your skiing.  It appears you have already seen the beneficial results of adjusting for LLD---way to go.  

     Foot note---adjusting LLD without a Rx is practicing medicine without a license.

     You are close about the percentages but a little on the low side, I have read that 90+% of adults have a discrepancy of from 1 to 10mm and 42% have greater than 10mm---there is nothing truly symmetrical about a human body.

     Find a good bootfitter/cped get this fixed correctly.

Thanks for the feedback, Mike. I have never had a fitter even mention LLD, so I don't think many check for it -- at least the ones I have visited didn''t. Then again, I don't visit west coast/rocky mountain shops, and they seem to be the most experienced. Everything for me has always been about about lateral alignment and footbeds. I just stumbled onto this by accident, on my own, and it was quite a difference.

I don't think a visit to a foot doctor is in order for me though -- I am just going to go by what I feel. I am going to try the new setup and experiment with it in the boots.  The Mojo boots are just something I picked up dirt cheap and have't even used so it's worth an experiment.  I was rollerblading all summer with the 5mm shim and the performance increase and neutral feel was was quite astounding. More control and more stability and balance. It's amazing what just 5mm can do.  After a while, I tried skating without the shim and it was pretty obvious how much less balance and neutrality I had.  

To reiterate what was different from the boots with the 1.5 degree cant compared to the lift alone -- with the cant-out, it feels like my foot is being 'placed' into a neutral position wheras with just the shim on the left foot, it feels like both feet aree naturally where they wante to be - flat. I think since my left leg is a tad shorter, the right knee was always compensating by rolling inwards a bit and the result was a 1.5 degree knock-kneed stance on the right leg. Who nows, I am not a doctor and don't advise people not to seek professional assiatance, but I think this is a pretty simple fix that seems to have worked for the skates so not sure why it wouldn't work for the boots. . 

mojoman

you are correct- your knock kneed stance is your bodies STRATEGY for equalizing length.  a couple of direction changes later and you are relatively statically balanced. however, begin to act DYNAMICALLY and those direction changes start to have a negative effect.  Have your LLD determined and then get aligned.

and as for LLD - I had the daughter of a national team physio in for set up this summer and even her physio parent did not notice the LLD- or think about it at least.

Well, my queston now is, if LLD is so important to good balance and stance and so many people have this condition, why don't most fitters check for this and why is it hardly ever discussed or mentioned? As stated, in the past, everything that has taken place with my dealings with fitters has been centered on footbeds and lateral canting to make sure feet are flat. LLD has never been mentioned or even suggested. Perhaps, because as Mike stated, only a registered pedorthist can legally diagnose or address the problem?

Out of curiosity, I just read up a bit on the subject and it seems there are three kinds of LLD- those who have a hip rotation that causes one leg to lift; those who have development LLD where one leg has actually grown at a diffeetn rate and is smaller; and those who have had a broken bone or some other injury that causes the discrepancy. Everything I have read indicates that a  majority of people have some discrpency and for about 25%, it is signifigant enough to seriously effect how they walk, stand etc. With a sport like skiing, rollerblading etc, I would think having this addressed is pretty crucial before anything else is evaluated or done to the boots. It rarely is mentioned though. Perhaps many may not need canting at all, just a shim. 

Now, I cannot cant rollerblades but can say that the sensation I get from using a lift is totally different from having the foot canted out. With a canted ski boot, I get the feel that the foot that is canted out really doesn't want to be there but it is being told to 'stay there' so the skis stay flat. Using the lift on the left foot, the right knee goes back to an automatic netrual position and tracks straight, even under high forces while turning and skiing switch on ther blades. Less strain, less exertion, didn't tire as quick and felt completely in balance. Without the lift, I cannot skate two-footed without making major adjustments. The lift also feels 'normal' as opposed to the forced position of canting the right foot outwards I would get in a canted boot. Totally different feel. 

I discovered this completely by accident and, using the rollerbaldes. They actually sell individual lifts for rollerblades to deal with alingment issues. I discovered that a 5mm shim works to perfection, the 3mm shim isn't as good and the 8mm shim was clearly too much and the problem reversed- I started bowing in with my left knee instead of the right.

It seems then that then if you have a LLD, adjusting the LL difference will address the issues that perhaps is causing the alingment problem, wheras canting will force the foot to deal with the discrepancy caused by LLD.

 

Hard to answer all your questions but you are correct about the types of leg length discrepancy and I suspect but admit I don't have the statistics that most are due to  pelvis/back misalignment.  If that is correct is shows the problems with simply correcting the situation in the shop.  If the problem is due to pelvis misalignment perhaps the fix is chiro/stretching/physio, etc.

Also don't know about the need to correct it, but it probably depends on skier.  Had a 1st year FIS athlete in a month ago who had been diagnosed with LLD by doc.  Symptoms included persistent back pain.  We corrected LLD on skis for his Austria camp.  According to him and coach, no diff.

Lou