How to determine if YOU have a leg length difference? (for stronger cycling)

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Over the past 12-18 months we have had many requests to discuss leg length discrepancy for cyclists. Notably, how can you determine if YOU have a leg length difference from the comfort of your own home. Length length discrepancy is a very common cause of right or left sided hip and knee pain, and can be a ticket (once resolved) to more power on the bike .
#bike #fitting #tips

[@rav3nst33l]

Every time i watch one of these videos it makes me wish i lived in Australia to have a fit with Neil.

[@cpac54]

Same here!

[@frazmars]

I think this almost every day

[@sigfreed11]

Is there a website that defines a list of great fitters like Neil across the world?

[@Bikes-n-Stuff]

Same

[@sharakorr]

This is a great series. Neil giving his insights is always super valuable

[@cb465]

I could listen to this guy all day on bike fit!

[@patrickparisienne1917]

Absolutely fantastic content guys! Neill is doing himself out of a dollar! Seriously this is great to empower cyclists to fix problems for a better experience, and eventually, a bike fit. Keep it up guys!

[@stevestewart-sturges2159]

Cardboard insole.... genius, that idea alone is amazing... Cheers, Neil!

[@bradleyandrews4007]

This is the content I’ve been waiting for! Fellow phisio with a discrepancy here and a relatively new cyclist. I’ve been lazy and figured I’d get around to trying a wedge inside my shoe at some point but this sounds much more comfortable and biomechanically correct. Thanks.

[@thedownunderverse]

I think on-bike leg discrepancy indicators are as important as off-bike testing. Personally, my saddle height has always been a compromise - if I set saddle height to compliment my right leg stroke, my left leg has to “reach” and toe down. If I set saddle height to compliment left leg, my right leg doesn’t extend enough (and heel can drop). Solution: shim(s) under left leg!

[@ilittleflyingboy]

That can also be the result of a pelvit tilt. But yeah, another way of checking for leg length discrenpency.

[@thedownunderverse]

@@ilittleflyingboy update: shorter cranks (165mm from 170mm) fixed all.

[@lancescarborough1]

You said you would and you did!!! Thank you!!!

[@game-day870]

Thanks for this. Neil mentioned using a shim on your other channel and I have discovered I had a lower leg discrepancy from that video. I added a shim around that time which has springboard my training and my performance drastically.

[@roadcyclingacademy]

Thanks for sharing on the thread mate, great to hear

[@maxshen1177]

Great fitting seris, really helped me a lot of self improvement and solve issues when cycling, thanks!

[@koDiacc]

I also have a functional leg length discrepancy which is caused by a twisted pelvis. I improved it a lot by off-the-bike work and I feel this should be the approach. using a shim should only be used when having a real leg length discrepancy. whenever its just muscular we should aim to fix the issue, not the symptom. (for everyone: hip flexors, core and glute medius for leveling up your pelvis)

[@anderscronberg8038]

Exactly, I just had professional help getting my pelvis straightened (fascia loosening), and it removed my leg asymmetri

[@altern8tive]

Having had right leg issues for a while when I heard the cardboard suggestion just to check I felt so dumb not to have thought of that myself 🤦‍♂️😄 Thanks Cam and Neill

[@evrimkaya8420]

Thank you so much for this. You already solved my issue of having too much weight on my hands by listening your advice of (counter-intuitively) lowering my handle bars. Thanks to this video my partner was able to confirm that my left leg is 4 mm shorter. (I didn’t tell her which one i was suspecting of being shorter) I just installed a 2 mm shim. Let’s see what happens. Hopefully it will solve my right side saddle sore.

[@grantparks3191]

Another approach is to measure the individual’s height standing on one leg, then on the other leg, or directly measure the femurs, etc. Large differences may require cranks of different lengths, such as my 25 mm difference. I use 172.5 on the right, and 165 on the left. 10:45

[@ocphil2709]

Great videos! Thank you!!! I've tried this shim thing with my attested 10mm shorter left leg. Until now there are 2mm under the cleat... Problem especially on my saddle are not gone. Now I'll just try to make it 5mm or 6mm again and give it a run! If Australia wouldn't be the other end of the world...I would make an appointment!

[@edsassler]

In day to day life, as soon as your foot leaves the ground it can take any path - it’s called freedom of movement, which is why a leg length difference isn’t such a big problem. Clip into a set of pedals and that freedom goes away... I started to study the effects of leg length discrepancies when I started coaching. There’s both an X and Y component here, the shim is the Y offset, the relative cleat fore/aft position is the X offset. I can take measurements, but I’m more interested in the differences in forces generated, which I can’t see. I’m using vector force information while the client is pedaling to see the differences between the two sides. I can even subtract one side from the other, which makes the difference pretty clear. As a general rule, the femur is a horizontal member while the tibia is a vertical connecting rod (which is why you find tibia differences to require larger shims). Very often a client will come in with a pain over the iliac ridge on the longer side. The force analysis shows that they are pushing forward on that side (keeping those muscles from coming out of tension). My answer there is a small change in fore/aft position on the cleats. There isn’t much room there before other problems start popping up... This series is wonderful, it’s forced me to rethink my fitting process in so many ways. I’m learning a lot, but I still have a New Jersey accent...

[@danielfenner3659]

Thanks again for another great video and love the channel. I like many others have thought I need a good fit but through these videos have tweeked a few things and even had to add a shim on my left leg and after every adjustment have felt better and seem to be riding a bit faster and more consistent.

[@joelsoto1849]

Thanks Neil! Thanks Cam! Had been reaching out about this specific topic. Thrilled to see it finally up.

[@joelsoto1849]

Got to add, this topic could be a mini series with so many rabbit holes 🐇. The pains and physical manifestations and explanations would be fascinating. Yup struggled mightily with it.

[@geoff2824]

I have a 3.5cm discrepancy. My left tibia is much shorter after dodgy 'corrective' surgery. Cycling is much more challenging than it used to be.

[@jvladrac]

Thanks for this Cam and Neill!

[@geothunder1971]

I started with a 3mm shim on my left leg, rode with it for a couple of rides but it didn't feel right. I bought a pack of 1mm shims and started at 1mm and ended up needing another settling on 2mm shim height. It's a world of difference!

[@LittleJulio.]

You guys are making me mental 🤣 Every video I say to myself, yep I have that issue and start fiddling with my setup! But seriously, is obvious single leg underdevelopment a definite sign of leg length discrepancy and/or hip alignment? Thoughts on the Retul bike fit?

[@roadcyclingacademy]

haha! Neill does the same to me.This is a question for Neill. I'll see if he can get to it for you. Cam

[@MrYetibaby]

I also have a leg difference. 1 cm . And it was sorted out with G8s fenomenal heelcup . I needed my ankle on the shorter leg to track better . And It got massivly better by that cup . As always , such an awsome episode by you guys 🙏🏼

[@roadcyclingacademy]

Interesting to hear that, thanks for sharing on the thread!

[@chrisaltec2992]

I got my partner to measure from my hip bone to my ankle bone using sewing tape. I'm sure isn't accurate, but my right leg came up 9mm shorter. Put 6mm worth of Shimano shims under my right cleat, and I've never been so comfortable on the bike... Should have tested all of this 10+ years ago!

[@andengpintado7833]

What a coinsidence, i was thinking yesterday that I'd ask you a question regarding my 24mm short leg and what should i do with my cleats.

[@livenhfree]

One idea I had was just to sit on a chair that affords close to a 90 degree bend at the knee and run a level across the top of my knees. I suppose that could be relatively informative? Thanks for this video.

[@lukedunn6107]

Visually mediated lateral tilt? Can you make a video about this?or can you link if you already have one made?

[@Southerncyclist]

My left leg is over 10mm shorter, probably 20. I run .250thousandths shim. Learned this from Chiropractor long time ago. Then I had a problem after a long ride when I started cycling. So added the . 250 thousandths to my left leg. Way better after that. I run speed plays.

[@roadcyclingacademy]

Thanks for sharing on the thread. Cam

[@Zhiloreznik]

Mine is 24mm. I can compensate with seat hight and heal drop. Trade off is which knee will hurt at what given hight.

[@sagar9060]

Is it confirmed via scans? Do you visibly limp?

[@Zhiloreznik]

@@sagar9060 Yeah I wore orthopedic insoles as a kid ... good luck wearing cool shoes having an inch tall heel inserts :) People usually ask me after few times meeting me if I hurt my leg or something ... My walking gate is a bit off but I hide is well

[@sagar9060]

@@Zhiloreznik how old are you? Is it because of any fracture? What did orthos tell about this? Is that difference going to cause you any future problems in back, hip etc.?

[@Zhiloreznik]

@@sagar9060 I’m over 30. No major issues. Why it’s shorter? Born dead and one side didn’t develop as nicely. In reality leg length imbalances are common, just that much is less common. One guy that I know had multiple inches. In that case they break your leg and mount a leg stretch thing on.

[@sagar9060]

@@Zhiloreznik insole is not a permanent solution. Did you consider the lengthening surgery anytime before? Majorly because the difference might lead to pelvis and back problems later in the future...what did orthopedics advice on this? Will it cause any hip or back issue? How did you manage the psychological and social part of this shortness... Like you mentioned the limping part and different gait.

[@milkbunnies]

I got hit by a car when I was 13 and I know I have a hip/leg discrepancy. Walking doing martial arts for decades never had an issue, but I could always tell one leg was working way harder on the bike. I put a shim on my left shoe about 3 years ago and any issues like hotspots etc just evaporated.

[@woodskid4ever]

Would a longer femur also present a taller patella with knees bent and lying supine?

[@wellok7860]

lets say me and my friend got same leg length but my femur is longer than his, and my shin bone is shorter. which one of us has more advantage in cycling?

[@maxkrug2000]

The longer I watch him the more I realize I need to go see a professional bike fitter

[@jbandt]

Interesting topic. I can tell my right leg is a little shorter. I can actually feel the difference while walking and even more so while biking. I've lowered the seat a bit to not over extend the right knee, but I can tell the left leg isnt getting the optimal extension. With seat height optimized for the left leg, the right is noticeably overextended.

[@roadcyclingacademy]

Interesting to hear, thanks for sharing on the thread Jason.

[@atpkompressor]

Thank you very much! My difference in l/r Power is 45/55. on which site could i try to put cleats under? Thx and greets from Germany

[@jesustapia4894]

Excellent. Can you help me please. I have a discrepancy on my left leg. I have a 40 mm tibia and 2 mm femur short. How may mm of shim i have to use?

[@sbp57]

Would you also suggest balancing the shim height with an equivalent heel raise too? I know that heel lifts/full sole orthotics are used for LLD outside of the bike. It seems that just raising the forefoot doesn't follow this principle for LLD resolving for walking/etc.

[@Alex-k6c7i]

good video!

[@Belfreyite]

This opens a number of questions on my discrepancy. Some while back I broke my left ankle. Subsequently, a Chiropodist measured my legs and found my right leg to be 4mm shorter. I recently got a Physio to re measure them and although they were equal in length overall, knee to ankle on my right side was 4mm shorter. I understand that this discrepancy might cause right knee pain over time, especially when cycling and walking. This was revealed during a bike fit and I am getting my right cleat shimmed. That's where the fun started, when I cast around for suitable shimming systems. There is a plethora of shims and I've gone for a FORM V2 arrangement which has a kind of cradle to stabilise the cleat. I recently started to suffer quite chronic saddle sores, in particular soft tissue bruising on my inside right thigh, all pointing to a connection with the short lower right leg.

[@proctermorris6657]

Hi Cam and Neill. I am loving these video's as I've been experimenting myself with these issues for a while now. 1. The spacers of varying heights (from 1mm to 4mm) have been going in and out of my left leg. The thing I am having trouble with seems to be not the feeling at the bottom of the pedal stroke on the left, but more at the top. Is this a common problem? 2. I'm not sure how to describe it, it's like I feel compressed at the top, and it's a feeling I am struggling to get past, and it seems to impede me. How long should I give myself with these things to see if it works out? I know you mentioned it passing, but interestingly my left leg is dominant by a couple of percent on power distribution, however, observationally, I think I have less control over my heel alignment through the pedal stroke on the left side. And yet when it comes to weight training, it's my right hamstring that suffers more, so is probably weaker. I am also aware that my calf development is different from left to right. My left foot also seems to be slightly bigger in length, maybe by 3mm or so also. All things point to some sort of asymmetry issue. I've been told I have a 4mm shorter left leg by my Osteo, but I will get my other half to do some of these measurements. Any suggestions on time frame for sticking with something. Other than booking an appointment with Neill - when borders reopen... 3. And what direction would you go if it is a pelvic alignment issue vs a structural issue? Cheers, Procter from Wollongong

[@patrickparisienne1917]

I think you need to book a fit with Neill!!

[@31.8mm]

yea it sound complicated, need to look in person, i myself probably will look at crank arm, arch support, rotation, and tilt

[@proctermorris6657]

Agreed on going to an actual bike fit. Trying to find one you trust is hard I guess. I was thinking of going to Canberra to see Steve Hogg being in Wollongong, then Covid (Delta) hit, but could be arm twisted to go to Queensland too. I've had a bike fit in the past that was supposed to be Retul. But I think it was a half arsed job in hindsight for many reasons. No chain on the bike on the trainer was one. I wasn't too fussed at the time, as it was part of a purchase of a new bike and I was confident in my position back then. But I have really started looking at it all properly recently. Not for any injury reason, more that I just feel out of alignment and not square.

[@roadcyclingacademy]

Not sure Neill will get to this one Procter, but feel free to email him through his website! He's pretty good there. Cam

[@AL21-i2d]

What about cleat setup fore and aft? I do have a leg length difference - and at least part of it seems to be in the femur. Using SPD for my gravel bike, there really seem to be no shims available in germany. About 30 € for UK imports seem a little out of proportion... Anyways, I set one cleat about 1 mm further back and it felt like a revelation. I was sitting straight(er) on the saddle and felt both legs working a lot more evenly.

[@roadcyclingacademy]

kzbin.info/www/bejne/eXqpg398Zd2IiM0 go to 6mins

[@KingKoolSimon]

Thanks a lot for all the videos. Helped me quite a lot and I realized I was going the wrong direction. Any idea how you could address the issue of different leg lengths with flat pedals?

[@davedudley4539]

insoles

[@johanelkjr9865]

Can I ask a q about measuring leg length? Is this a safe way to measure my self: with the heel on the pedal I'm pedalling backward. I lower my sadlle untill me ledt leg can't reach. I'm trying to sit square. Then I keep untill the other leg can't reach. The difference is somewhere close to 10 mm. Is this way "safe". I'm now riding with 6 mm spacer under the cleat on the shorter leg. I believe I'm sitting more even.

[@brucehumphries6889]

What about MTB shoes? How do we shim those?

[@JohnnyRabbitQC]

Check out the company called Form bikefitting they make a kit for 2 hole cleats, Neill Stanbury recently made a video about these shim kits.

[@dake4080]

Hi Cam and Neil, I have a question: are there also shims for SPD or mountainbike cleats? I use SPD cleats instead of a road cleat.

[@31.8mm]

yes they are, uncommon to see one but it's available, there's even a walkable version.

[@roadcyclingacademy]

Yes!

[@jefferyanderson5266]

Had a CT scan results were the right lower extremity measures 86.7 cm and the left lower extremity measures 88.4 cm. Would a shim be worth while and how much ?

[@sagar9060]

Do you limp while walking?

[@Rus5ell]

will the structurally shorter leg tend to be less musclier than the longer leg?

[@paulgabatan5089]

Is it possible to put shims on both shoes?

[@blahqwe]

Hi, great video, thanks!!! I've had a pain around the top of my right buttock. Is that likely to be a symptom of leg discrepancy? Just can't think what else would cause pain on only one side. Also does the same rule apply for SPDs? Thanks so much.

[@roadcyclingacademy]

Hey, thanks for the comment. There could be a few different issues causing your pain, an overall too long reach or too high seat height can also cause these problems. We would recommend going to see a reputable bike fitter to solve your issues! -RCA Team

[@blahqwe]

@@roadcyclingacademy cheers!

[@cyclopedia134]

i have an orthopedic implant in my left femur, because it was broke last 2018, and they need to put an implant and as of now its inside of my body.,is there a possibility that it will cause leg length discrepancy? thank you very much in advance :)

[@tomstephenson5452]

I did all these tests and my left leg seems shorter than my right, but I drop my right hip, any tips in which foot I should shim?

[@roadcyclingacademy]

Definitely the shorter leg.

[@OldDavo1950]

Interesting topic, I have had a reverse shoulder reconstruction right side. I now can see that my right arm is at least 1cm shorter at full stretch. Not sure at present as to shorten my stem length. Any views on this.

[@roadcyclingacademy]

Sorry David, Neill has been run off his feet and unable to get to the KZbin Q's recently. Cam

[@mtripolt1]

hey, since an accident my right lower leg is about 15 mm shorter than the left one, i have no problems when cycling, but should i still get such spacers to avoid long term problems (hips, or something else)? thx markus

[@sagar9060]

Is the discrepancy detected via scan? Do you limp while walking?

[@10ktube]

Is there a difference between shimming the cleat, and shimming from the insole? Does shimming the cleat cause the foot to tilt due to instability?

[@roadcyclingacademy]

Shimming from the insole would create an awkward sensation around the foot. There is no tilting that I have experienced, and I doubt it would be used as a solution if that was the case. Cam

[@davidhaddox]

Rt leg 8 mm short in femur, but still dominant and more muscular leg. Never have pain in rt leg. Left leg, longer, weaker leg, non-dom side. Cycling for 10+ years with little correction, in my 30s now and having strong left medial knee pain after 1hr of riding no matter the intensity or rest going in, after 1 he it hurts. Could right leg shim help left leg feel better? Could compensation be causing the left knee pain some how?

[@roadcyclingacademy]

Hey David, It's great to see that you are looking for more comfort on the bike. Unfortunately Neill can't answer all YT questions. We would recommend seeking a good bike fitter in your area as there can be multiple causes to a single problem. -Thanks, RCA Team

[@andrewbarker7709]

Some years ago when I was running, I was told I have a 1.5cm difference in leg length. When I started cycling some years ago it was suggested I used a 1cm shim (left leg). According to my power meter I am putting about 5-10w more through this leg which I guess could be caused by other factors. 1) should I increase the stack to equal my 1.5cm discrepancy? It’s a heck of a stack! 2) could I achieve a similar (better?) effect by having a 170’cm crank on the non-drive side and a 172.5cm crank in the drive side? Just thinking…..

[@ShadowzKiller]

Maybe consider your stance. The q-factor on one side could be quite different from the other and affect your balance.

[@andrewbarker7709]

@@ShadowzKiller wonderful thinking. Thank you!

[@maxgoldberg3818]

Hey I have a question, whenever I ride (usually 50-80 miles) I end up having extreme pain in my left calf muscle, but my right leg feels completely fine. I have never had my bike fitted before as well. Do you have any ideas as to why my left calf hurts so much? I also feel a good deal of knee pain in my left leg while riding.

[@mpgunawan]

Put your cleats further back, lower your saddle. Good luck.

[@maxgoldberg3818]

@@mpgunawan thank you for the tip

[@roadcyclingacademy]

Hey Max, it's hard to say. So many variables, but lowering the seat and placing the cleats further back is a good starting point. See here kzbin.info/www/bejne/hYGkhHuiodCkgK8

[@maxgoldberg3818]

@@roadcyclingacademy thank you very much, have a good day.

[@quintennn]

I know I have a difference of 14mm due to a broken leg, in my regular shoes I have an insole that raises 7mm. What height shim should I try?

[@roadcyclingacademy]

If the difference is known to be 14, then that's where you should start. Good luck. Cam

[@sagar9060]

Do you have limp? And is the 14mm. difference confirmed via scans?

[@quintennn]

@@sagar9060 with my insoles I don't really, my body is able to compensate, however when I get tired I do have one, start to waggle like a penguin a bit (I don't notice it, people behind me do). Difference is confirmed on scans indeed.

[@sagar9060]

@@quintennn oh. How old are you? You mentioned broken leg...is it femur or tibia that's short? Did you speak with your surgeon as to why the bone wasn't restored to it's original length during surgery? How many hours a day due you use the shoe lift? And what future problems(if at all) you might face due to the shortening? I suppose there's pelvis tilt in your case... Will it lead to any hip, back or spine problem further in life?

[@Emcai01]

I so want to come to Brisbane for a fit from you! There are no fitters here, and I know I am as bent as a banana 😂. I just don't feek like I am good enough at riding yet.

[@jonpoon3896]

Are there shims for off road/gravel?

[@roadcyclingacademy]

Anything cycling Jon

[@jonpoon3896]

@@roadcyclingacademy I guess it’s just low supply for mtb shims at the moment

[@bryansamson5667]

Great video. Would different crank lengths, say a 175 on the left to a 170 on the right, not be a more complete fix (albeit more costly), so as to fix hip angle differences while also correcting the leg length imbalance

[@31.8mm]

i think a plastic like from a used detergent bottle can be better than a cardboard

[@roadcyclingacademy]

haha nice one, let us know how it goes. Cam

[@WhiteRiceCycling]

My right femur is 5mm longer than my left but my left tibial is 5mm longer than my right.. 😅

[@Terrierized]

Hey Cam fix the thumbnail it says LEGTH not LENGTH

[@roadcyclingacademy]

Thanks mate, appreciate it. I have the serious problem of trying to do too many things at once! Fixed. Cam

[@Nessunego]

I've got this thing measured almost 6 times with diffrent values from different professionals. Given the high degree of error in the measurement process, also the thickness of the spacer plates varied. I ended up completely ignoring this thing and I removed all the spacers. If we say that for cycling a leg discrepancy of just a few millimiters matters, we can conclude that leg discrepancy measurements need to be nearly perfect. Given that this is really not the case, we can just completely ignore this thing. A natural leg discrepancy of 4-6mm is not worse than a discrepancy of 4-6mm due to incorrect correction caused by not perfect measurement of leg length discrepancy.

[@roadcyclingacademy]

Noted - I'll go and let my two clients today (who both had a painful left knee from a small leg length discrepancy, funnily enough on opposite legs) know that we should just let their knees hurt as we can't determine the height of the shim properly. Thanks for the input - Neill

[@ronfeldman4386]

Wow, Neil sure makes the bike fitters in my area look like idiots. If I ever travel to Australia I am going to have a bike fit done by the best.

[@speedking8546]

Yeah it's not even close, there really isn't anybody like him XD

[@trentbryan8226]

What about artificial leg length discrepancy caused buy lower back injuries

[@roadcyclingacademy]

Not sure myself Trent, that is a Q for Neill and not sure if he'll get to this. Cam

[@CG-99]

use the spell checker on your titles for a more professional look! - can’t spell LENGTH correctly

[@CG-99]

@@DaleRC75 take a look at the thumbnail image in your KZbin feed - it is spelt "LEGTH" - i would be embarrassed by such a school boy error if it was my youtube channel - so just looking to highlight it to the channel owner so he can correct it if he wishes to.

[@roadcyclingacademy]

Yes, it's fixed now. The spell checker doesn't work on the design tool and it was just an oversight. Cheers, Cam

[@dougprw1110]

Are you really a chiropractor? It sure seems like it. This is nothing but complete garbage and not scientific.