Quiz #1 for the bike fitters :re scoliosis

My background is a chiropractor and not a pro bike fitter. However, I have an interesting case that came into my office regarding bike fitting. I am actually thinking of writing this up in a professional journal. In the spirit of Xantusia/FIST and all the bike fitting posts on this forum I’ve decided to put this up to you fellow forum members as a quiz and ask for any thoughts and possible solutions. At the end of today I’ll post what worked as a solution.

We are dealing with a thirty-five yr. old female AG triathlete who is starting her third season in the sport, participating in sprint events. She had a competitive cross country running background at college and has ben a recreational swimmer and cyclist. She is unique in that she has quite a severe scoliosis which at age 12 required the permanent fitting of a Harrington rod by an orthopaedic surgeon. A scoliosis is an abnormal S shaped curvature of the spine. The sugically implated Harrington rod is designed to prevent this form getting any worse.

Her biomechanics are unique. With the spine being S shaped rather than strait when viewed from the front, she is an estimated two to three inches shorter than she would be,increases her proportionate leg to torso ratio compared to normal. The Harrington rod runs from the third thoracic vertebra to the second lumbar verterbra, preventing normal movement in this area of the spine. My examination demonstrated quite limited gross spinal movement with rotation and extension, but amazingly, she had excellent flexion (bending forward to touch toes). I concluded that most of this forward motion was because of above average flexibility in her hip joints and hamstrings, possibly developed as compensatory mechanism to the lack of spinal mobility. X-rays revealed moderate disc degeneration in the upper thoracic and lower lumbar spine in the areas where the Harrington rod is attached. This early disc thinning is a common finding with Harrington rods due to the biomechanical forces in this area.

Because of the Harrington rod, she has a sightly noticeable different walking and running gait and when swimming is unable to rotate her body as in the ideal swim stroke. Despite a seemingly obvious handicap, last year in the six sprint tris she ran, two 1st’s, a 2nd, two 3rd’s, and a fifth were obtained in her age group.

She purchased a Giant OCR fitted with Profile Jammer GT aero bars. This was set up in the classical road position by the LBS without paying attention to her unique situation. She developed neck, low back and knee pain while riding. It was then she brought the bike to me for a fitting. She has also recently purchased a Cervelo P2K which was also set up for her with this scoliosis/Harrington rod condition in mind.

So I’m throwing this out to you fellow forum members for suggestion before revealing how a solution was found. Tom, Dan, Gerard, Endurosport and all you others at Xantusia, let’s hear what your approach might be. Anyone else as well. I’ll post what we did later.

Hmmm. What a surprise. Not one even attempt, despite all this talk about fitting on this forum. I hoped that this might have turned into an interesting discussion about how to approach an unusual fitting issue. Since I started this thread, I’ll have to finish it. So if anyone out there is interested…

In all fairness to the LBS they made the right choice in frame selection by fitting her to a small size OCR. Sizes were limited since Giant only make the frame in three sizes. If her upper body proportion was normal without the scoliosis this triathlete would have likely been fitted to a medium frame as she sort of on the cusp between the two sizes, but with her shorter torso the small size was the right decision. Problem was when the seat height was set using the LeMond formula of multiplying inseam by .883, the top of the seat was a fair distance above the top tube. The LBS also fitted a normal length stem which would prove to be inappropriate.

I mentioned that the triathlete had surprising flexibilty in her hips and hamstrings but none from the upper lumbar to upper thoracic spine due to the Harrington rod. The only part of the spine that had flexibility was the lower lumbar spine which along with the hip joints would take all the flexibility of the body. With handlebars set in a lower position, her low back hurt due to the fact that this was the only part of the spine with flex while sitting on a bike seat.

The only solution was to go to a sort of “big slam” position with a shorter stem as Cobb suggests. But instead of moving the seat back and down as done in this position, instead we moved the handle bars a bit higher thus effectively also shortenning the top tube measurement to compensate for the unusual shorter torso and it’s lack of normal flexibility. Using the short Profile Jammer GT aero bars this works quite well and she is very comfortable and pain free while riding in this position. The top of the aero bar pads is only slightly lower than the top of her seat. This is obviously not an aggressive aero position but is obviously one that works well for her unusual biomechanics since she was consistantly a front bike split in her AG in the six sprint tris she ran last year.

At the end of the season she purchased a Cervelo P2K. Although she didn’t get to race on it as of yet, she did ride it quite a bit and we were able to set it up for her in a way that she feels very comfortable.

This tri bike was purchased from well known tri shop, but like the LBS where she bought the Giant, they also didn’t seem to have any comprehension of the biomechanical significance of having a scoliosis and a Harrington rod in your back. They initially wanted to sell a size bigger than what I suggested. In the end they agreed that a better choice would be to buy a size smaller to compensate for the short torso length. Fitting this bike we did ourselves rather than use the pro services of the bike shop, since they just didn’t seem to “get it” about the Harrington rod.

Obviously this rider can not ride in an aggressive steep position due to the lack of spinal flexibility. Also with the short torso/long legs, this would tend to indicate a more shallow angle based upon also her longer femur length ratio compared to the lower leg. We set it up at about 75/76 degrees. The handlebars needed setting with only one spacer more elevation than normal and the one size smaller frame compensates well for the short torso. She feels very fast and powerful on her new P2K and considering how well she did in her AG on a Giant last year, we expect that she should do even better next year.

She does have a small bit of knee pain on one side due to a physiologically short leg due to pelvic rotation related to the scoliosis. This isn’t severe but we’re hoping to either solve this with orthotics or a spacer under the cleat.

So that’s it. The moral of this story is that dots in space and measurements are all fine, but in the real world no “cookbook” system will work for everybody since some people have very special biomechanical requirements.

Bike fitting is not mysticism or is it rocket science. It’s mostly just common sense.

Any comment?

Hey Cerveloguy

At least this is very interesting for me personally as i carry the same S-curve in the spine and have had the same problems finding a frame that fit. Allthough i dont have the rod injected in me i have the same proportions with very long legs/short torso and perhaps limited flexibility - eventhough i never thought of that (never tried anything else).

For years i have tried to find a comfortable and fast position on too large frames (as recommended by LBS) as my inseam of 93cm will normally require a 60-61 cm frame per normal standards, height is 188cm. But i found out the hard (and expensive ) way that the top tube of 58-59cm is way to long for me and i need something shorter. Then the next reality kicks in when looking for a smaller frame with shorter toptube in the 56cm range - the headtube would be too short and resulting in backpains and a uncomfortable position with too low front end (or a huuuuuge stack of spacers).

I have now finally found a standard frame that suits me with a shorter toptube and a comparably taller headtube (L56cm/H17,4cm) which i am looking forward to trying out when the last salt clears away from the roads here.

I have eventually concluded that a “big-slam” position is the one for me with a short Syntace C2 bar and approx 75 degrees.

I must say that if anyone had dialed me in the right direction those 13 years ago when i purchased my first frame of 62cm. Well, then I could have save a lot of time and money that I have invested in some 14-15 different bikes ( oh, well I must admit that i also enjoy to change equipment now and then)

Thanks for the very interesting post

You are correct, commonsense has its use in cycling.
But where to start using it, is another question. As
I see it, how you pedal solves many problems and
if you have the correct style, it soon lets you know the correct positioning and setting up of the bike.
You say she has very flexible hips and hamstrings;
with the ideal pedaling style, put these together with
a strong pair of arms and she could be top rider
because the ideal (Anquetil’s) pedaling technique
generates all pedal power between hips and shoes
without any use of the lower back as in normal
pedaling, eliminating even the worst cycling related
lower back pain in the process.
While all research today is concentrated on undetectable drugs and expensive equipment, the
most important aspect of cycling is forgotten.

Hi, i just happened upon this forum and have a question for you (if you don’t mind…)
i have scoliosis with harrington rod, and also have shorter left leg (1cm). i’ve always had great back pain cycling, but as i have this in other sports as well and in general life, i’ve just learnt to deal with it. but now that i’m doing longer distances and doing a half ironman in 2 months i’m trying to eliminate as much as possible. obviously bike set up is important but i really found your comment interesting re pedal stroke and lower back pain. ***The ideal (Anquetil’s) pedaling technique ***
generates all pedal power between hips and shoes
without any use of the lower back as in normal
pedaling, eliminating even the worst cycling related
lower back pain in the process.

i’ve tried to find information on this technique but can’t really. is it basically a ‘toe dipper’ stroke? possibly then able to sit a little higher as one has a longer length? i am quite flexible and trying to open hip flexors as much as possible as well.
many thanks, if you get a chance to reply
kind regards
kim

I have seen help with longer leg by using a longer pedal spindle.

Its interesting that my 11 yr old post still brings replies. Wow, I’ve been hanging around here a long time!

HA!!! never noticed that, funny

Hi, i just happened upon this forum and have a question for you (if you don’t mind…)
i have scoliosis with harrington rod, and also have shorter left leg (1cm). i’ve always had great back pain cycling, but as i have this in other sports as well and in general life, i’ve just learnt to deal with it. but now that i’m doing longer distances and doing a half ironman in 2 months i’m trying to eliminate as much as possible. obviously bike set up is important but i really found your comment interesting re pedal stroke and lower back pain. ***The ideal (Anquetil’s) pedaling technique ***
generates all pedal power between hips and shoes
without any use of the lower back as in normal
pedaling, eliminating even the worst cycling related
lower back pain in the process.

i’ve tried to find information on this technique but can’t really. is it basically a ‘toe dipper’ stroke? possibly then able to sit a little higher as one has a longer length? i am quite flexible and trying to open hip flexors as much as possible as well.
many thanks, if you get a chance to reply
kind regards
kim

It is a dark path you are about to take.

Hi, i just happened upon this forum and have a question for you (if you don’t mind…)
i have scoliosis with harrington rod, and also have shorter left leg (1cm). i’ve always had great back pain cycling, but as i have this in other sports as well and in general life, i’ve just learnt to deal with it. but now that i’m doing longer distances and doing a half ironman in 2 months i’m trying to eliminate as much as possible. obviously bike set up is important but i really found your comment interesting re pedal stroke and lower back pain. ***The ideal (Anquetil’s) pedaling technique ***
generates all pedal power between hips and shoes
without any use of the lower back as in normal
pedaling, eliminating even the worst cycling related
lower back pain in the process.

i’ve tried to find information on this technique but can’t really. is it basically a ‘toe dipper’ stroke? possibly then able to sit a little higher as one has a longer length? i am quite flexible and trying to open hip flexors as much as possible as well.
many thanks, if you get a chance to reply
kind regards
kim

It is a dark path you are about to take.

This technique is completely different from all natural styles, it has no dead spot sector. Instead of idling through TDC and applying minimal torque at 1 o’c, this technique applies continuous maximal torque through 12, 1, 2 and 3 o’c, starting the power stroke at 11 and ending at 5 o’c. As for toe-dipping, it depends on your position on saddle, forward it will be toes down and rearward it will be in a neutral or flat position and this is because of how the force is being applied to the pedal, it is coming from the hip through the knee instead of directly downwards from the knee as in natural pedalling. This together with the fact that all upper bodyweight is independently supported when in the racing drops position is what eliminates all stress from the lower back. It is an ideal technique for uninterrupted constant high gear maximal power output in time trials. While I have tried to explain this technique many times, it is too complicated for people to understand, it would need a person to person detailed explanation and demonstration, I hope Brim Bros new PM soon to be available will confirm that my claims are genuine and demonstrate what is possible in pedaling by a simple change in the use of muscles.

Hey Cerveloguy,

I was amazed to hear about the special personal interest you took in that one case - since I have actually made it my “New Year’s Resolution” to completely stop going to doctors/physiotherapists in my country. They never treat their patients as unique cases. First of all, we don’t have a normal sports injury treating doctor I could visit and this is incredibly frustrating, since all the other doctors are just used to dealing with older people who don’t exercise/move at all - and they treat me, a young 30 year old recreational female triathlete with the same regime. Anyway, I was also diagnosed with scoliosis, after complaining of unbearable hip pain - a month after finishing my first 70.3 IronMan. They first said it was sciatica, then something that had to do with muscles, and in the end they couldn’t decide between a hip stress fracture, and something that had to do with the soft connective tissues in that region. I only know this - it all started with back pain. I lost more than 2 months worth of training, and my lower back (+ knee on opposite side) pain returned as soon as I started biking again, even though I had it refitted about a 100 times. When I have back pain, you can actually feel swelling on the spot that hurts, and it usually goes away, depending on the severity of the pain (a day to three later). I am guessing my bike doesn’t fit as it should - and I don’t have professional fitters close to where I live. Would it be possible for me to contact you in some way other than this forum (I actually joined the forum today, just because of your post!)?

Another member of the “Harrington Rodder tri club” checking in…

In registered for my first 140.6 this year, and my biggest concern is dealing with the back and neck pain on the bike… but her, who doesn’t love a challenge.

I thought I’d add to this thread even thought it’s quite old. Ran across it searching about triathletes with scoliosis. With my scoliosis (mine is a 20% curve and I’ve had no surgery), I have found that my Felt road bike that was fitted by a wonderful bike shop (with whom I did not share info about my condition) has served me quite well. It never even occurred to me to mention it to them. After long rides, I put my efforts into physical therapy including stretching, using a roller, massage, hot tub, and Advil. It’s a constant battle with pain, but somewhere there is a balance between the pain that goes along with daily living and the pain of training for triathlon. My philosophy is that it hurts worse when I don’t work out. I’m turning 60 and have done two sprint triathalons. I think your efforts on behalf of your patient are quite admirable.