Wednesday, September 2, 2009
Sorry..
...I've been away for awhile. Life happened, but I am working back into the swing of things. I've been playing catch up and have done about 25 bike fits in the last 3 weeks, so I think I will have some good ammo to put out there. I may even have a hand-made steel road bike to sell at a discount as well. Stay tuned...
Tuesday, July 7, 2009
The Womens Specific Myth
I get asked a lot from my female clients that come to me for a fitting before they buy a bike (which is the right way to do it -- get a professional sizing done first, THEN buy a new bike and complete the fitting process on it) wondering which "womens specific" bike they should get.
First let me say that, certainly there are many ladies out there that are quite comfortable on their womens specific bike; and they can work out great. But in general, the idea that women need different geometry is a myth.
Let's start by looking at it from an industry standpoint. What are the major bike manufacturers doing? They seem to go one of two ways:
1. They take the men's line of bikes, eliminating the sizes over 57cm, stick narrow handlebars, 170mm cranks, a softer seat, and accent the paint with pink or purple.
A good example of this is Cannondale:
Compare the "like-sized" bikes and you'll find no difference whatsoever in their geometry; same effective top tube, head tube, angles, standover, etc. They use narrower handlebars, presumably a shorter stem or straighter (non-setback) seatpost because they tout a shorter cockpit length, and shorter cranks. (Also girlie colors.)
2. Others do all of the above and then shorten the top tube (and possibly lengthen the head tube).
The truth is that some women do well with option number 1 and others do well with option number 2 .......
........but so do most men.
Taking the 2nd option, where they actually change the length of a few tubes on the bike, assumes that relative to their height women have shorter torsos and/or shorter arms (and possibly less flexibility). While many women do have shorter torsos (and therefore are long legged) their numbers do not outnumber their more proportionate or long-torsoed breathren in great enough numbers to warrant a change in all their bike geometry, I think. Even if you accept that long-legged, short-torsoed women represent the center of the bell curve and have that large of a representation, then changes that the bike companies make to design a "woman's" bike are often not different enough to accommodate the women who actually need it -- on the order of a 1 - 2 centimeter shorter top tube and possibly 1 - 1.5 cm longer on the head tube.
Incidentally, this is the approach that Specialized, Look, Cervelo, among many others take when designing a "higher handlebar position bike" or one they tout to be used in Paris-Roubaix. These are designed for men and women. So it's good that they make these changes, but often I don't think they are completely filling the market niches -- which is why when I build so many custom bikes for people who don't fit these niches.
So I know, now it sounds like that first I was complaining that they make the changes at all and then I complain that they need to make even greater changes. But that's what I think they should do....
.....but they should do the same thing for the men's bikes as well. They should have two or three *grades* of sizing from more aggressive to more relaxed.
Some companies are doing this to a small degree, but, again, usually the changes don't go far enough. Or the more relaxed geometries available are built like Bradley Fighting Vehicles and don't come in a performance package at all. I don't think it's wrong for people to want to ride their bikes hard and have nice components and wheels WHILE being comfortable. Our cycling population is getting older, but a lot of these riders still want to compete or at least continue doing big rides.
So I'm okay with companies NOT changing the geometry specifically for their women's bikes. I'm also okay with them changing the geometry -- it just doesn't need to be "womens specific." Even riders with Y chromosomes need geometry adjustment to optimize their fit.
As long as the stock bike manufacturers continue to err on the side of producing bike geometry with a racing-inspired pedigree, this will continue to be an issue. Unfortunately many cyclists will be sold a bike that does not match their riding strengths, simply because it is all that is available.
Custom bike manufacturers (like Seven Cycles) should continue to benefit from this oversight, especially as the cost of a stock bike and a custom bike continue to get closer and closer together. (Take a look at Seven's Gateway Program and then look at some of the cost of Specialized's Tarmac line, Trek's Madone, Cannondale's SuperSix -- many of those stock bikes get up close to $10,000 in their higher iterations!)
So when anyone (man or woman) is looking for a new bike, find out first what size bike you need and if any special considerations to the geometry of the bike ought to be made. There may be a stock option out there for you. If you think your current bike and fit are pretty good take a look at the setup -- if you have a threaded stem that is set to the "Minimum Insert" line or your stem is short length and/or high rise, then you might be in need of some additional adaptations to your bike geometry.
Why not just have the high rise or short stem on there (or the saddle slid all the way forward or backward on the rails for that matter)?
The problem with making these changes is that the handling of the bike is not built around these set-ups. These changes can work to make the bike fit better and be more comfortable, but they can also begin to affect the handling and the balance of the bike.
It's bad enough that the big stock manufacturers make forks with only 1 or 2 offsets and rakes to use on all their bikes -- from their 62cm down to their 49cm bikes.
(SIDE NOTE: Very small bikes and very big bikes should have forks with different offsets, but this costs money, so there are very limited options in forks out there and the big bike companies try to make up the difference with the head angles of the bikes. When doing this, one end of the spectrum -- either the big or the small -- will have compromised handling. Some of the companies, when listing the geometry for different sizes will even list some of the fork offsets and not list the others, saying they are "proprietary". Having used the Zin to log in the geometry and setup of my client's bikes -- which gives you fork rake and trail among many other measurements -- I can tell you that many times the rake of the fork is not different from the other listed sizes, the manufacturer just chooses to hide the fact that it is the same fork.)
So then when we change the handlebar height or seat fore-aft significantly on these bikes the handling and safety can sometimes suffer.
So do some research, go see a professional bike fitter that can help you find what will work best for you, and if you plan to spend more than $3000, don't discount a custom bike if it suits your needs better than the stock offerings.
Ride well.
First let me say that, certainly there are many ladies out there that are quite comfortable on their womens specific bike; and they can work out great. But in general, the idea that women need different geometry is a myth.
Let's start by looking at it from an industry standpoint. What are the major bike manufacturers doing? They seem to go one of two ways:
1. They take the men's line of bikes, eliminating the sizes over 57cm, stick narrow handlebars, 170mm cranks, a softer seat, and accent the paint with pink or purple.
A good example of this is Cannondale:
Compare the "like-sized" bikes and you'll find no difference whatsoever in their geometry; same effective top tube, head tube, angles, standover, etc. They use narrower handlebars, presumably a shorter stem or straighter (non-setback) seatpost because they tout a shorter cockpit length, and shorter cranks. (Also girlie colors.)
2. Others do all of the above and then shorten the top tube (and possibly lengthen the head tube).
The truth is that some women do well with option number 1 and others do well with option number 2 .......
........but so do most men.
Taking the 2nd option, where they actually change the length of a few tubes on the bike, assumes that relative to their height women have shorter torsos and/or shorter arms (and possibly less flexibility). While many women do have shorter torsos (and therefore are long legged) their numbers do not outnumber their more proportionate or long-torsoed breathren in great enough numbers to warrant a change in all their bike geometry, I think. Even if you accept that long-legged, short-torsoed women represent the center of the bell curve and have that large of a representation, then changes that the bike companies make to design a "woman's" bike are often not different enough to accommodate the women who actually need it -- on the order of a 1 - 2 centimeter shorter top tube and possibly 1 - 1.5 cm longer on the head tube.
Incidentally, this is the approach that Specialized, Look, Cervelo, among many others take when designing a "higher handlebar position bike" or one they tout to be used in Paris-Roubaix. These are designed for men and women. So it's good that they make these changes, but often I don't think they are completely filling the market niches -- which is why when I build so many custom bikes for people who don't fit these niches.
So I know, now it sounds like that first I was complaining that they make the changes at all and then I complain that they need to make even greater changes. But that's what I think they should do....
.....but they should do the same thing for the men's bikes as well. They should have two or three *grades* of sizing from more aggressive to more relaxed.
Some companies are doing this to a small degree, but, again, usually the changes don't go far enough. Or the more relaxed geometries available are built like Bradley Fighting Vehicles and don't come in a performance package at all. I don't think it's wrong for people to want to ride their bikes hard and have nice components and wheels WHILE being comfortable. Our cycling population is getting older, but a lot of these riders still want to compete or at least continue doing big rides.
So I'm okay with companies NOT changing the geometry specifically for their women's bikes. I'm also okay with them changing the geometry -- it just doesn't need to be "womens specific." Even riders with Y chromosomes need geometry adjustment to optimize their fit.
As long as the stock bike manufacturers continue to err on the side of producing bike geometry with a racing-inspired pedigree, this will continue to be an issue. Unfortunately many cyclists will be sold a bike that does not match their riding strengths, simply because it is all that is available.
Custom bike manufacturers (like Seven Cycles) should continue to benefit from this oversight, especially as the cost of a stock bike and a custom bike continue to get closer and closer together. (Take a look at Seven's Gateway Program and then look at some of the cost of Specialized's Tarmac line, Trek's Madone, Cannondale's SuperSix -- many of those stock bikes get up close to $10,000 in their higher iterations!)
So when anyone (man or woman) is looking for a new bike, find out first what size bike you need and if any special considerations to the geometry of the bike ought to be made. There may be a stock option out there for you. If you think your current bike and fit are pretty good take a look at the setup -- if you have a threaded stem that is set to the "Minimum Insert" line or your stem is short length and/or high rise, then you might be in need of some additional adaptations to your bike geometry.
Why not just have the high rise or short stem on there (or the saddle slid all the way forward or backward on the rails for that matter)?
The problem with making these changes is that the handling of the bike is not built around these set-ups. These changes can work to make the bike fit better and be more comfortable, but they can also begin to affect the handling and the balance of the bike.
It's bad enough that the big stock manufacturers make forks with only 1 or 2 offsets and rakes to use on all their bikes -- from their 62cm down to their 49cm bikes.
(SIDE NOTE: Very small bikes and very big bikes should have forks with different offsets, but this costs money, so there are very limited options in forks out there and the big bike companies try to make up the difference with the head angles of the bikes. When doing this, one end of the spectrum -- either the big or the small -- will have compromised handling. Some of the companies, when listing the geometry for different sizes will even list some of the fork offsets and not list the others, saying they are "proprietary". Having used the Zin to log in the geometry and setup of my client's bikes -- which gives you fork rake and trail among many other measurements -- I can tell you that many times the rake of the fork is not different from the other listed sizes, the manufacturer just chooses to hide the fact that it is the same fork.)
So then when we change the handlebar height or seat fore-aft significantly on these bikes the handling and safety can sometimes suffer.
So do some research, go see a professional bike fitter that can help you find what will work best for you, and if you plan to spend more than $3000, don't discount a custom bike if it suits your needs better than the stock offerings.
Ride well.
Wednesday, June 24, 2009
Felt B2 triathlon bike fit
I'm just recovering from a weekend of doing bike fits out of town. Occasionally I do this -- mostly around western Colorado and eastern Utah. When I have 3 or more interested clients (that seems to be my comfortable threshold right now for a proper "driving time/fitting fee" ratio -- at least for a 2 - 2.5 hour drive) I will make the trip out to them and set up in a corner somewhere all my equipment.
The Retul travels quite well. It packs away neatly into (what I am told is) a gun case. The most difficult thing to plan for is to have enough parts and equipment for as many possible fitting changes as possible. Carrying a few dozen stems of various sizes is no problem -- it's the handlebars (because of their size), and seatposts (too many different diameters) that are tough.
So anyway, I was in beautiful Basalt, Colorado this Saturday and Sunday to see a number of clients. I ended up doing about 11 hours worth of fittings on Saturday and another 3 hours on Sunday, so you can begin to get an idea of why I am "recovering".
Lots of very nice people, ages ranging from in their 30's to the upper 70's. Yep, you read that right. There are some very fit folks out in this part of the country.
One client that was a lot of fun was Dave C. He is an avid long distance triathlete; he just finished a 70.3 in Boise the week before. He is very fit, motivated, and attentive -- your basic Type A triathlete. He listened very well and asked a lot of good questions - exactly the type of client I like to work with, because the more a client knows about what is going on, the more likely it is they will see the complexity of the decisions that need to be made in their bike fitting. This is a client who will see the process, as we do it, for what it is -- a service that is one of a kind and geared toward only making their bike work better for them.
So Dave is fit, but like all human beings who live on the modern world of driving cars, computer work, and tools that do our work for us, he has a few imbalances:
+ one leg is stronger and more coordinated than the other
+ he is asymmetric through his shoulder motion and strength
+ he has a small twist originating in his lumbar spine
+ somewhat weak intrinsic foot muscles and resultant pronation tendencies, etc. etc.
When you start to list all these things out, you get the impression that he's a wreck -- not so. This is very typical of what I find in my initial body assessment (he actually has fewer and smaller issues than many).
He has some neck discomfort when on the bike for a while; recovering from some knee pain, of the tendinitis sort, and some back pain on occasion as well.
Here are his first two Retul files that we took:
He had his (very well appointed and beautifully built) Felt B2 set up in the more relaxed seatpost position, and had also put on a stem of equal length to the original it came with, but now with more rise to raise the aerobars up some.
Many times I see people where their pedal stroke clearly has a hitch or hesitation in it, but Dave has spent too much time on his bike for that. His issue was more subtle. After doing this for ten years, I can see that his pedal stroke, while very practiced and relatively smooth, seems slightly disjointed. It's almost as if his upper and lower body are working independently of each other, rather than together.
After looking at the Retul files, it was clear his left side was getting sacrificed -- it had more lateral knee travel and the knee tracked at about an 8 degree angle, not to mention more hip motion.
I was more concerned with his angles at his elbow and shoulder, however. The angle at his elbows was almost 100 degrees and his shoulders were open and rather stretched out (the Retul takes two different shoulder or "armpit" angles -- to the elbow and the wrist). When your shoulders are stretched out like that a few things happen. First, your lats (latissimus dorsi) are lengthened and if they are pulled too far, they can exert a force on the lower thoracic and lumbar spine where they originate. This decreases the mobility of the lower half of the spine. Also, the shoulder blades, or scapulae have to move with our shoulder joints, so when the shoulder is flexed excessively, the shoulder blades must protract (move outward), thereby stretching the muscles that attach the shoulder blade to the mid-thoracic spine. Just like with the lats, this decreases the mobility of this portion of the spine. Take a look at this picture and you can see this with the "round-ness" of his back.
Also, note where the elbow and the shoulder dot are located, with the elbow being in front. In the aero position, we would like to support ourselves (especially the upper body) with as little active muscular input as possible, and if we need to use muscles, we'd want to use respiratory muscles (muscles we use in breathing) as little as possible. Often, when the elbow and shoulder have this relative position we are using excessive upper body muscular force to hold us up, rather than just "resting" on our skeletal support.
Corrections:
So to fix things I wanted to first address the upper body, lower body disconnect I was seeing. Dave's Felt was built with a two position seatpost, and he originally had it in the further back, relaxed seat angle position, so we changed it to the steeper configuration. We also made sure the seat was level (a huge mistake that triathletes make with respect to saddle position is to nose-down the saddle to reduce pressure on their perineum. This just causes you to bear more weight on your upper body as you constantly slip off the front of the saddle -- I always think of it as "tripod-ing" on the bike) and made a small seat height adjustment to accommodate the now-level seat.
This fit is proof that a higher handlebar position isn't always more "relaxed" or comfortable. Because we were rotating his hips forward and up over the bottom bracket, and because Dave has good fitness and strength in the right areas, we were able to lower his handlebars and in the process we put his upper body biomechanically where it needed to go. We improved his power, we reduced the muscular requirement to hold himself on his bike (he will have a front heavy sensation on the bike for a while since we brought his center of gravity forward on the bike, but this will decrease as his body begins to proprioceptively "get it") and improved his aerodynamics all with just two changes.
His left side was being sacrificed, as I said before, and we needed to get it in the game. It is less coordinated and not as strong, so we put a couple of forefoot wedges in his left shoe to improve that foot's contact with the pedal. Over time, this correction, will begin to re-train the muscles in the left leg and hip to get through the pedal stroke without inhibiting the right side.
Here is an after photo to compare with the previous one:
Look at how much more relaxed his spine looks. His elbows are tucked underneath him nicely, and because we've taken stress off the muscles supporting the shoulder blades (which incidentally also attach to the neck) he is able to move his head easier from side to side and look up. Go back and look at the first photo -- see the impression that his shoulder blade makes under the skin. No such impression on the after picture because that shoulder blade is resting more comfortably on the back of the rib cage rather than on the side of it.
The position is definitely more compact, and will take some adjustment time -- but luckily Dave is in a step-down period of his training, so he'll benefit from some moderate rides to allow his body to adapt. We may still make some minor tweaks in the near future, but I think he now has a good long distance tri bike position to keep him powerful for a full 112 miles. (But I'll let Dave himself comment here on how the fit is working, if he'd like)
The Retul travels quite well. It packs away neatly into (what I am told is) a gun case. The most difficult thing to plan for is to have enough parts and equipment for as many possible fitting changes as possible. Carrying a few dozen stems of various sizes is no problem -- it's the handlebars (because of their size), and seatposts (too many different diameters) that are tough.
So anyway, I was in beautiful Basalt, Colorado this Saturday and Sunday to see a number of clients. I ended up doing about 11 hours worth of fittings on Saturday and another 3 hours on Sunday, so you can begin to get an idea of why I am "recovering".
Lots of very nice people, ages ranging from in their 30's to the upper 70's. Yep, you read that right. There are some very fit folks out in this part of the country.
One client that was a lot of fun was Dave C. He is an avid long distance triathlete; he just finished a 70.3 in Boise the week before. He is very fit, motivated, and attentive -- your basic Type A triathlete. He listened very well and asked a lot of good questions - exactly the type of client I like to work with, because the more a client knows about what is going on, the more likely it is they will see the complexity of the decisions that need to be made in their bike fitting. This is a client who will see the process, as we do it, for what it is -- a service that is one of a kind and geared toward only making their bike work better for them.
So Dave is fit, but like all human beings who live on the modern world of driving cars, computer work, and tools that do our work for us, he has a few imbalances:
+ one leg is stronger and more coordinated than the other
+ he is asymmetric through his shoulder motion and strength
+ he has a small twist originating in his lumbar spine
+ somewhat weak intrinsic foot muscles and resultant pronation tendencies, etc. etc.
When you start to list all these things out, you get the impression that he's a wreck -- not so. This is very typical of what I find in my initial body assessment (he actually has fewer and smaller issues than many).
He has some neck discomfort when on the bike for a while; recovering from some knee pain, of the tendinitis sort, and some back pain on occasion as well.
Here are his first two Retul files that we took:
He had his (very well appointed and beautifully built) Felt B2 set up in the more relaxed seatpost position, and had also put on a stem of equal length to the original it came with, but now with more rise to raise the aerobars up some.
Many times I see people where their pedal stroke clearly has a hitch or hesitation in it, but Dave has spent too much time on his bike for that. His issue was more subtle. After doing this for ten years, I can see that his pedal stroke, while very practiced and relatively smooth, seems slightly disjointed. It's almost as if his upper and lower body are working independently of each other, rather than together.
After looking at the Retul files, it was clear his left side was getting sacrificed -- it had more lateral knee travel and the knee tracked at about an 8 degree angle, not to mention more hip motion.
I was more concerned with his angles at his elbow and shoulder, however. The angle at his elbows was almost 100 degrees and his shoulders were open and rather stretched out (the Retul takes two different shoulder or "armpit" angles -- to the elbow and the wrist). When your shoulders are stretched out like that a few things happen. First, your lats (latissimus dorsi) are lengthened and if they are pulled too far, they can exert a force on the lower thoracic and lumbar spine where they originate. This decreases the mobility of the lower half of the spine. Also, the shoulder blades, or scapulae have to move with our shoulder joints, so when the shoulder is flexed excessively, the shoulder blades must protract (move outward), thereby stretching the muscles that attach the shoulder blade to the mid-thoracic spine. Just like with the lats, this decreases the mobility of this portion of the spine. Take a look at this picture and you can see this with the "round-ness" of his back.
Also, note where the elbow and the shoulder dot are located, with the elbow being in front. In the aero position, we would like to support ourselves (especially the upper body) with as little active muscular input as possible, and if we need to use muscles, we'd want to use respiratory muscles (muscles we use in breathing) as little as possible. Often, when the elbow and shoulder have this relative position we are using excessive upper body muscular force to hold us up, rather than just "resting" on our skeletal support.
Corrections:
So to fix things I wanted to first address the upper body, lower body disconnect I was seeing. Dave's Felt was built with a two position seatpost, and he originally had it in the further back, relaxed seat angle position, so we changed it to the steeper configuration. We also made sure the seat was level (a huge mistake that triathletes make with respect to saddle position is to nose-down the saddle to reduce pressure on their perineum. This just causes you to bear more weight on your upper body as you constantly slip off the front of the saddle -- I always think of it as "tripod-ing" on the bike) and made a small seat height adjustment to accommodate the now-level seat.
This fit is proof that a higher handlebar position isn't always more "relaxed" or comfortable. Because we were rotating his hips forward and up over the bottom bracket, and because Dave has good fitness and strength in the right areas, we were able to lower his handlebars and in the process we put his upper body biomechanically where it needed to go. We improved his power, we reduced the muscular requirement to hold himself on his bike (he will have a front heavy sensation on the bike for a while since we brought his center of gravity forward on the bike, but this will decrease as his body begins to proprioceptively "get it") and improved his aerodynamics all with just two changes.
His left side was being sacrificed, as I said before, and we needed to get it in the game. It is less coordinated and not as strong, so we put a couple of forefoot wedges in his left shoe to improve that foot's contact with the pedal. Over time, this correction, will begin to re-train the muscles in the left leg and hip to get through the pedal stroke without inhibiting the right side.
Here is an after photo to compare with the previous one:
Look at how much more relaxed his spine looks. His elbows are tucked underneath him nicely, and because we've taken stress off the muscles supporting the shoulder blades (which incidentally also attach to the neck) he is able to move his head easier from side to side and look up. Go back and look at the first photo -- see the impression that his shoulder blade makes under the skin. No such impression on the after picture because that shoulder blade is resting more comfortably on the back of the rib cage rather than on the side of it.
The position is definitely more compact, and will take some adjustment time -- but luckily Dave is in a step-down period of his training, so he'll benefit from some moderate rides to allow his body to adapt. We may still make some minor tweaks in the near future, but I think he now has a good long distance tri bike position to keep him powerful for a full 112 miles. (But I'll let Dave himself comment here on how the fit is working, if he'd like)
Monday, June 1, 2009
Front of the knee pain, but first....
Someone asked me a good question the other day:
By writing this blog, aren't you worried about giving away the bike fitting secrets that you've learned and inceasing your competition?
I guess I never really thought about it that way. To me, it's like an architect being worried that by explaining to his clients how their house is drawn up, then they'll use that information to finish the project on their own. There is just too much to know, and most folks, while they may find the information interesting (and I hope everyone does -- I know it can be a bit dry, but we are all nerdy cyclists at heart, and this is the stuff we love to read about), it's not likely anyone is going to be able to read my blog and open up shop on their own based solely on this information. I think it's important that there are practitioners of bike fitting out there that are taking the process more seriously, and treating it as it should be treated -- a very complex, biomechanics-based area of study, and not just a bike shop service.
So now onto the technical stuff.
One of the most common problems I see on the bike is frontal knee pain. Sometimes it is a force issue (just pushing too big of a gear for too long)
(brief diversion)
****I frequently get front of the knee pain (on the right) as I get back into riding shape. My seat height is good, I sit fairly straight on the saddle (see HERE); so what's the problem? As you can see from some of the biofeedback studies we did HERE, when I am not fit, my pedal stroke is not very efficient and I tend to be right leg dominant (like most of the population) AND I am very quadricep dominant when re-learning my pedal stroke. I am just pushing too much with my right leg and the choppy nature of my pedal stroke is requiring more of my quads, so my kneecap and patellar tendon are under tremendous strain.****
(and we're back...)
, but it can also be a patellar tracking issue, IT Band problems (and, incidentally, patellar tracking and IT band sometimes are not mutually exclusive), increased patellar compression/chondromalacia, or even referred or radicular lumbar pain.
The common "fix" you hear about with front of the knee pain is that your saddle is too low and raising it is necessary. Many times this is the case, but it becomes less likely when the pain is only on one side. (If you have a leg length discrepancy or your pelvis sits skewed on the saddle, the seat height may be too low for one leg and perfect or too high for the other leg; in this case you have to figure out why you aren't sitting symmetrically on the saddle first, and fix that)
So if your seat height is okay, where to next? One often overlooked area is how we toe in and toe out. In much of the research it is called inversion (toeing in) and eversion (toeing out) which on the bike is a little different than the motion we refer to as inversion and eversion in biomechanics. On the bike because of how the cleat fastens to the pedal the motion is truly just toeing in and toeing out, but in biomechanics-speak, the toes go in (medially) with inversion, but the bottom of the foot actually points in (medially) as well; opposite for eversion.
Generally when we invert our feet on the bike it drives the knee and increases what's called a valgus force on the knee (valgus = think of looking at the knee straight on and a force presses on the knee from the outside and forces it into a "knock-kneed" position). Conversely, when we evert our foot, we increase the varus force through the knee (think "bow-legged"). This valgus force at the knee essentially takes the ever-important medial quads out of the equation more. These medial quads (vastus medialis and a bit less correctly, VMO) are important because they need to be adequately active to keep the patella in between the two notches at the bottom of the femur. If the patella is not lined up then the underside of it gets dragged against the lateral notch and can cause cartilage damage and pain. The valgus force at the knee puts the medial quads at a mechanical disadvantage. Everting the foot a small amount may reduce this valgus force, and consequently allow the medial quads do their job and/or aid in patellar tracking.
All of this can be read in a great article by Gregersen, Hull, and Hakansson in the June 2006 Journal of Biomechanical Engineering:
How Changing the Inversion/Eversion Foot Angle Affects the Nondriving Intersegmental Knee Moments and the Relative Activation of the Vastii Muscles in Cycling by Gregersen CS, Hull ML, Hakansson NA
I have many clients who have front of the knee pain and the simple act of toeing their foot out (eversion) sometimes helps. Some clients can feel it "unlock" or "unload" their knee almost immediately.
So this is a good option to try if you are at a loss for your knee pain. Just keep in mind that like a lot of things in bike fitting, very tiny corrections are necessary most of the time. Also, remember that when you are changing cleat/foot position, you have to think in opposites: if you want to toe your foot out, you have to toe the cleat in.
But keep in mind that the consequences of toeing out (decreasing the "knock-kneed" force etc.) is what often, but not always, happens. Because we are all just experiments of one we cannot take this as the only consequence. I have, in fact, had some clients who show signs of an increased valgus force about the knee when they toe out. In at least one case it was due to some odd midfoot mechanics, but this cannot be discounted -- there are other people out their with these same mechanics and there are most certainly other movement asymmetries that could cause this eversion/varus relationship to break down as well.
By writing this blog, aren't you worried about giving away the bike fitting secrets that you've learned and inceasing your competition?
I guess I never really thought about it that way. To me, it's like an architect being worried that by explaining to his clients how their house is drawn up, then they'll use that information to finish the project on their own. There is just too much to know, and most folks, while they may find the information interesting (and I hope everyone does -- I know it can be a bit dry, but we are all nerdy cyclists at heart, and this is the stuff we love to read about), it's not likely anyone is going to be able to read my blog and open up shop on their own based solely on this information. I think it's important that there are practitioners of bike fitting out there that are taking the process more seriously, and treating it as it should be treated -- a very complex, biomechanics-based area of study, and not just a bike shop service.
So now onto the technical stuff.
One of the most common problems I see on the bike is frontal knee pain. Sometimes it is a force issue (just pushing too big of a gear for too long)
(brief diversion)
****I frequently get front of the knee pain (on the right) as I get back into riding shape. My seat height is good, I sit fairly straight on the saddle (see HERE); so what's the problem? As you can see from some of the biofeedback studies we did HERE, when I am not fit, my pedal stroke is not very efficient and I tend to be right leg dominant (like most of the population) AND I am very quadricep dominant when re-learning my pedal stroke. I am just pushing too much with my right leg and the choppy nature of my pedal stroke is requiring more of my quads, so my kneecap and patellar tendon are under tremendous strain.****
(and we're back...)
, but it can also be a patellar tracking issue, IT Band problems (and, incidentally, patellar tracking and IT band sometimes are not mutually exclusive), increased patellar compression/chondromalacia, or even referred or radicular lumbar pain.
The common "fix" you hear about with front of the knee pain is that your saddle is too low and raising it is necessary. Many times this is the case, but it becomes less likely when the pain is only on one side. (If you have a leg length discrepancy or your pelvis sits skewed on the saddle, the seat height may be too low for one leg and perfect or too high for the other leg; in this case you have to figure out why you aren't sitting symmetrically on the saddle first, and fix that)
So if your seat height is okay, where to next? One often overlooked area is how we toe in and toe out. In much of the research it is called inversion (toeing in) and eversion (toeing out) which on the bike is a little different than the motion we refer to as inversion and eversion in biomechanics. On the bike because of how the cleat fastens to the pedal the motion is truly just toeing in and toeing out, but in biomechanics-speak, the toes go in (medially) with inversion, but the bottom of the foot actually points in (medially) as well; opposite for eversion.
Generally when we invert our feet on the bike it drives the knee and increases what's called a valgus force on the knee (valgus = think of looking at the knee straight on and a force presses on the knee from the outside and forces it into a "knock-kneed" position). Conversely, when we evert our foot, we increase the varus force through the knee (think "bow-legged"). This valgus force at the knee essentially takes the ever-important medial quads out of the equation more. These medial quads (vastus medialis and a bit less correctly, VMO) are important because they need to be adequately active to keep the patella in between the two notches at the bottom of the femur. If the patella is not lined up then the underside of it gets dragged against the lateral notch and can cause cartilage damage and pain. The valgus force at the knee puts the medial quads at a mechanical disadvantage. Everting the foot a small amount may reduce this valgus force, and consequently allow the medial quads do their job and/or aid in patellar tracking.
All of this can be read in a great article by Gregersen, Hull, and Hakansson in the June 2006 Journal of Biomechanical Engineering:
How Changing the Inversion/Eversion Foot Angle Affects the Nondriving Intersegmental Knee Moments and the Relative Activation of the Vastii Muscles in Cycling by Gregersen CS, Hull ML, Hakansson NA
I have many clients who have front of the knee pain and the simple act of toeing their foot out (eversion) sometimes helps. Some clients can feel it "unlock" or "unload" their knee almost immediately.
So this is a good option to try if you are at a loss for your knee pain. Just keep in mind that like a lot of things in bike fitting, very tiny corrections are necessary most of the time. Also, remember that when you are changing cleat/foot position, you have to think in opposites: if you want to toe your foot out, you have to toe the cleat in.
But keep in mind that the consequences of toeing out (decreasing the "knock-kneed" force etc.) is what often, but not always, happens. Because we are all just experiments of one we cannot take this as the only consequence. I have, in fact, had some clients who show signs of an increased valgus force about the knee when they toe out. In at least one case it was due to some odd midfoot mechanics, but this cannot be discounted -- there are other people out their with these same mechanics and there are most certainly other movement asymmetries that could cause this eversion/varus relationship to break down as well.
Thursday, May 28, 2009
Retul Bike fits
If you've read my blog before you know that I use the Retul system of motion capture (www.retul.com). I get a lot of questions about it -- and a lot of business frankly.
I often hear,
"Wow, that must really make the fittings easier, huh?"
After using the system for a while now I finally have an answer to that. Does it make the fittings easier? The short answer is "No", unequivocally, it does not make the process simpler.
Blasphemy, right? Retul is definitely the most influential technology to come into bike fitting in, well, maybe forever, and here I am dissing it?
Well, I don't think it is a "knock" on the system because it doesn't make bike fits easier. People and companies (i.e. Specialized) have been taking a reductionist approach to bike fitting and it has done nothing positive to the process. The *Fit Kit", *BG Fit*, *Wobblenaught* among others have tried to take this very complex process and turn it into a nice neat, packaged "revenue driver" that every bike shop in the world can become an expert in.
I think it is actually a tribute to the system that it doesn't "dumb down" the process. It in no way tells you what you should do to take corrective action for the cyclist - it just provides a lot of very accurate data about the cyclist's mechanics.
For each of the parameters it measures -- for instance the frontal angle a rider's knee tracks at relative to the vertical, called Knee Travel Tilt -- Retul provides a range of normal limits that each one, in an ideal situation, should stay within.
The difficulty lies in the shear amount of data. If you focus on one measurement and make changes to the rider's position to "fix" just that one measurement, often other measurements that are also a problem, don't change or get worse.
So, no, my bike fitting process has not gotten simpler. But I'm not the least bit disappointed. Actually this has been the most productive and fun year for me with bike fittings (in my 12 years as a physical therapist).
My bike fittings have gotten better, and that's the important part. The Retul system has allowed a level of accuracy and confidence that is hard to beat. Plus when it comes to bike fitting, "simple" isn't always the best solution.
But "better" is.
Wednesday, May 6, 2009
Musings about credentials for bike fitting
I get asked a lot by people out of state, My next trip to Colorado, I'm going to come in for a fitting. But do you know anyone in my area that can do a good bike fitting?
That's a hard one. I don't have a lot of names that I trust implicitly to do a comprehensive bike fitting. I think by endorsing someone, I am putting my reputation in their hands. Not many people out there I would do that for. There are a few, and if you live in their territory I will let you know who they are.
I am pretty particular about my fitting process, and I think too many shops out there are relying on the WOW factor of their gadgets, and their client's....I don't want to say ignorance, because that seems harsh -- after all, bike shops should know bikes, and many riders just don't have the inclination to learn about their bike and that's just fine. That's why you have a bike shop! But many clients do trust that their bike shop knows all things bike. Bike fit included.
Unfortunately that is just not the case. Most bike shops know bikes. They should. "The bike" is the easy part in the equation of bike fitting. Truly, anyone with a little time and motivation can learn enough in a short time to WORK in a bike shop. Every year thousands of high school and college age kids begin working at a bike shop and in pretty short order they are assembling and repairing bikes right alongside the "career mechanic." There are bike mechanic schools out there, but very few people building bikes in the United States are attending them. I think that's a shame. It doesn't say much for the person who is a career mechanic and it certainly doesn't help them earn a better living. When you have a profession that is unregulated, unlicensed, and requires no formal training, then you just don't have to pay those people that much. (and by "you" I mean the market in general).
Side note: A very experienced and skilled bike mechanic is an amazing thing. They are such a wealth of bike knowledge that at times is indispensable. I want to be clear how much I respect the true experts of this discipline. My point is that you likely won't go to you bike mechanic for a bike fitting just as you wouldn't go to your bike fitter for a question about derailleur actuation ratios or air chamber pressures on your rear shock.
So to get back to my point, the bike is the easy part to learn about. The variables are few and relatively fixed.
The human body, however, is exactly the opposite. It's not likely that you are going to be able to "apprentice" with a doctor, or a PT, or an exercise physiologist, and learn their trade in a few weeks or months. There are too many variables, and what's more, often these variables are hidden under layers of skin, muscle and fascia, so an intimate knowledge of their location, function, and physiology is necessary. (Again, in contrast, most of a bike's parts are easily seen and quantified.)
So you can see how it would be easy for a bike shop to alter your bike for you, but difficult for them to explain to you why you need it changed.
Some bike shops will say that they have been doing bike fits long enough that they know the 10 most common syndromes associated with ill-fitting bikes, and that that covers them for most cyclists. I don't know about you, but I don't want to pay someone hundreds of dollars in a fitting fee and more money for new equipment if they don't KNOW that it is going to help. In the last ten years I have done more fittings than most bike shops in the country, and I would estimate that fully 25-35% had some combination of mechanical issues that manifested themselves on the bike in a way I had not seen before, and about 50% fell outside of what I would consider to be the "10 most common bike fit issues". In these situations I had to rely on my education and experience with the biomechanics of the human body.
To understand all these differences it takes time and lots and lots of clients -- I call it the "Malcolm Gladwell Effect". In his fantastic book Outliers: The Story of Success, he explains that thorough research has come up with a metric for understanding why some people become experts at the top of the field, and the general threshold for this is 10,000 hours of practice. Bill Gates began programming as a "tween" at a time when only a handful of people on the planet even had access to a computer to program on. Michael Jordan out-worked all his competitors by spending hours and hours EVERY single day to improve his skills.
Similarly, a bike fitter only gets to be an expert when they spend every day working their diagnostic muscles. This is where physical therapists and other clinicians have a huge advantage over bike shop employees and other fitters -- we get to practice and flex those same mental muscles every day, even outside of our bike fittings as we treat 5, 10, 15 clients a day. The treatments are different but the "work" and knowledge gained and reinforced is the same. Typically even a busy bike fitter may see 5-10 clients a week -- this would be an awfully slow way to learn the craft.
This also brings up a point that bike shops are in the business of selling bikes and bike parts. Unfortunately with the boom in the number of shops offering "fitting services" many did so because their industry advisors were telling them how many replacement parts and accessories they could sell.
I'm not trying to make people paranoid or distrustful of their LBS. Fact is I think there are plenty of shops out there TRYING to do the right thing. I just think that they in over their head with the complexity of many bike fits.
The difficulty lies in the fact that many people experience discomfort or a decrease in power and if you just LOOK at them, they appear to be set up in a very typical road position.
Example:
I had a client recently come in for a fitting on a bike she had bought a few months before. She hadn't ridden it much because she bought at the end of the fall and she was not a cold weather rider. She got a "good deal" on the bike. The young salesperson helping her helped her find the bike, they set her up on a trainer and she pedaled the bike for 2 or 3 minutes. It felt "Okay" (her words) while she was on the trainer, but to be sure, they stopped the lone "bike fit guru" (who is also the head mechanic and part owner) as he was rushing across the shop in search of a part for another client, to have a look. He watched her sit on the bike and pedal for 5 or 6 pedal strokes and declared, "Looks good." And he rushed off. Sometimes the shop (but really the client) might get lucky and everything might actually BE good.
In this case, however, once she spent more than 5 or 10 minutes on the bike it was clear she wasn't comfortable. So they came to see me, and this is when she had her second chance to get lucky -- the bike could be the right size but just need some adjustments - maybe we could "make it work". Unfortunately, the frame was the wrong size and to have an appropriate reach on the bike she'd need to have the seat all the way forward on the rails (with a 0 degree setback post) and a 60 mm stem -- definitely not ideal.
So what is the lesson with that story? Again, not that you should distrust your LBS, because I think this shop was TRYING to do the right thing (admittedly a bit half a**ed). They are just not very good at it.
Luckily there are more and more bike fitters that have education in anatomy, biomechanics etc. AND have years of experience applying this knowledge. These two things are incredibly important and you should do some digging to find out about any bike fitter you intend to visit.
That's a hard one. I don't have a lot of names that I trust implicitly to do a comprehensive bike fitting. I think by endorsing someone, I am putting my reputation in their hands. Not many people out there I would do that for. There are a few, and if you live in their territory I will let you know who they are.
I am pretty particular about my fitting process, and I think too many shops out there are relying on the WOW factor of their gadgets, and their client's....I don't want to say ignorance, because that seems harsh -- after all, bike shops should know bikes, and many riders just don't have the inclination to learn about their bike and that's just fine. That's why you have a bike shop! But many clients do trust that their bike shop knows all things bike. Bike fit included.
Unfortunately that is just not the case. Most bike shops know bikes. They should. "The bike" is the easy part in the equation of bike fitting. Truly, anyone with a little time and motivation can learn enough in a short time to WORK in a bike shop. Every year thousands of high school and college age kids begin working at a bike shop and in pretty short order they are assembling and repairing bikes right alongside the "career mechanic." There are bike mechanic schools out there, but very few people building bikes in the United States are attending them. I think that's a shame. It doesn't say much for the person who is a career mechanic and it certainly doesn't help them earn a better living. When you have a profession that is unregulated, unlicensed, and requires no formal training, then you just don't have to pay those people that much. (and by "you" I mean the market in general).
Side note: A very experienced and skilled bike mechanic is an amazing thing. They are such a wealth of bike knowledge that at times is indispensable. I want to be clear how much I respect the true experts of this discipline. My point is that you likely won't go to you bike mechanic for a bike fitting just as you wouldn't go to your bike fitter for a question about derailleur actuation ratios or air chamber pressures on your rear shock.
So to get back to my point, the bike is the easy part to learn about. The variables are few and relatively fixed.
The human body, however, is exactly the opposite. It's not likely that you are going to be able to "apprentice" with a doctor, or a PT, or an exercise physiologist, and learn their trade in a few weeks or months. There are too many variables, and what's more, often these variables are hidden under layers of skin, muscle and fascia, so an intimate knowledge of their location, function, and physiology is necessary. (Again, in contrast, most of a bike's parts are easily seen and quantified.)
So you can see how it would be easy for a bike shop to alter your bike for you, but difficult for them to explain to you why you need it changed.
Some bike shops will say that they have been doing bike fits long enough that they know the 10 most common syndromes associated with ill-fitting bikes, and that that covers them for most cyclists. I don't know about you, but I don't want to pay someone hundreds of dollars in a fitting fee and more money for new equipment if they don't KNOW that it is going to help. In the last ten years I have done more fittings than most bike shops in the country, and I would estimate that fully 25-35% had some combination of mechanical issues that manifested themselves on the bike in a way I had not seen before, and about 50% fell outside of what I would consider to be the "10 most common bike fit issues". In these situations I had to rely on my education and experience with the biomechanics of the human body.
To understand all these differences it takes time and lots and lots of clients -- I call it the "Malcolm Gladwell Effect". In his fantastic book Outliers: The Story of Success, he explains that thorough research has come up with a metric for understanding why some people become experts at the top of the field, and the general threshold for this is 10,000 hours of practice. Bill Gates began programming as a "tween" at a time when only a handful of people on the planet even had access to a computer to program on. Michael Jordan out-worked all his competitors by spending hours and hours EVERY single day to improve his skills.
Similarly, a bike fitter only gets to be an expert when they spend every day working their diagnostic muscles. This is where physical therapists and other clinicians have a huge advantage over bike shop employees and other fitters -- we get to practice and flex those same mental muscles every day, even outside of our bike fittings as we treat 5, 10, 15 clients a day. The treatments are different but the "work" and knowledge gained and reinforced is the same. Typically even a busy bike fitter may see 5-10 clients a week -- this would be an awfully slow way to learn the craft.
This also brings up a point that bike shops are in the business of selling bikes and bike parts. Unfortunately with the boom in the number of shops offering "fitting services" many did so because their industry advisors were telling them how many replacement parts and accessories they could sell.
I'm not trying to make people paranoid or distrustful of their LBS. Fact is I think there are plenty of shops out there TRYING to do the right thing. I just think that they in over their head with the complexity of many bike fits.
The difficulty lies in the fact that many people experience discomfort or a decrease in power and if you just LOOK at them, they appear to be set up in a very typical road position.
Example:
I had a client recently come in for a fitting on a bike she had bought a few months before. She hadn't ridden it much because she bought at the end of the fall and she was not a cold weather rider. She got a "good deal" on the bike. The young salesperson helping her helped her find the bike, they set her up on a trainer and she pedaled the bike for 2 or 3 minutes. It felt "Okay" (her words) while she was on the trainer, but to be sure, they stopped the lone "bike fit guru" (who is also the head mechanic and part owner) as he was rushing across the shop in search of a part for another client, to have a look. He watched her sit on the bike and pedal for 5 or 6 pedal strokes and declared, "Looks good." And he rushed off. Sometimes the shop (but really the client) might get lucky and everything might actually BE good.
In this case, however, once she spent more than 5 or 10 minutes on the bike it was clear she wasn't comfortable. So they came to see me, and this is when she had her second chance to get lucky -- the bike could be the right size but just need some adjustments - maybe we could "make it work". Unfortunately, the frame was the wrong size and to have an appropriate reach on the bike she'd need to have the seat all the way forward on the rails (with a 0 degree setback post) and a 60 mm stem -- definitely not ideal.
So what is the lesson with that story? Again, not that you should distrust your LBS, because I think this shop was TRYING to do the right thing (admittedly a bit half a**ed). They are just not very good at it.
Luckily there are more and more bike fitters that have education in anatomy, biomechanics etc. AND have years of experience applying this knowledge. These two things are incredibly important and you should do some digging to find out about any bike fitter you intend to visit.
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