Thursday, June 14, 2018

Knee Pain, Knee Alignment and Pedal Stance Width


In a previous article, I wrote in-depth about crankarm length and how crankarms that are too-long can cause knee-pain.
In this article, we will be concentrating on pedal stance width, and why it is important. This article focuses more on road bikes and triathlon / time trial bikes. These style bikes have close to the same bottom bracket shell widths and use the same or similar cranks. Mountain bikes, on the other hand, offer different crank widths (q-factor) such as 168mm, 175mm, 176mm, and even wider.
Figure 1 – Terminology

Terminology

First, let’s explain the difference between three different terms: pedal width, (pedal) stance width, and q-factor. These terms are often used interchangeably, but they really have different meanings. Following is their correct (cycling) definitions.
Pedal Width
Pedal Width (not shown in Figure 1) is the distance from the center of the pedal to the outside of the closest crankarm. Standard road pedal width is 53mm.
Stance Width 
Stance Width (or pedal stance width) is the distance between the center of one pedal to the center of the other pedal.
Q-factor
Q-factor (or quack-factor which is a reference to the wide stance and waddling gait of a duck) is the distance between the outside of one crankarm to the outside of the other crankarm measured at the points of the threaded portion where the pedal axle attaches.

The Problem and The Cause

When pedaling, there are 3 points for each leg that “pivot.”
  1. Femoral Head. Since you can’t see or feel your femoral head directly, the Greater Trochanter is the next best thing. The GT is the boney protrusion that you feel below the top of your hip (Iliac Crest). It is positioned so that it accurately represents the top pivot point.
  2. Knee. Simply defined, the knee divides the Femur and the Tibia/Fibula and is the joint that allows the leg to bend. To find this pivot point, locate the bottom of the Patella and move laterally to the outside center of the knee. This will be very close to the pivot point.
  3. Ankle. The easiest pivot point to locate. Just look for the Malleolus, or the protruding round bone commonly referred to as the ankle bone.
When pedaling, you want all of these pivot points aligned so that you are pushing straight down. Any angling will not only rob power, but worse, will place torque on your knees in a direction that is not natural – i.e. often resulting in knee damage or minimally, knee pain. Remember, cycling is an accumulation of micro-injuries and, if you want to continue cycling pain-free into your 60’s, 70’s, and even 80’s, it is essential to take care of yourself now.

What’s Going On?

The real culprit is the Bottom Bracket shell for road bikes – it’s too narrow for us Americans. The Europeans are generally thinner, narrower, lighter, shorter, smaller than us wider-hip Americans and when we lock our feet into a too-narrow stance. As we pedal, the knees have no other option than to oscillate (go out at the top of the pedal stroke and in at the bottom of the pedal stroke).
Mountain bikes bottom brackets and cranks are designed and built with a larger Q-factor that, in my experience places most MTB riders with the correct pedal stance. You will know if your pedal stance (usually determined more by Q-factor) is too wide. If too wide, your knees will start diving inward at the top. You might also experience knee pain as well.
Figure 2- Knee Alignment
Figure 2 above, shows the cause being Pedal Stance Width is too narrow resulting in the feet to be out of plumb with the hips, which causes the knees to go in and out with each pedal stroke. The round circles at the top of this figure represents the Greater Trochanter and is meant to show that the hips are badly out of plumb from the feet. At the bottom of this figure are the pedals and crank spindle. The yellow lines connect the feet, knees and pelvis. The only difference between the ‘cyclist’ on the left and the ‘cyclist’ on the right is the Pedal Stance Width. The ‘cyclists’ feet on the left are closer together, while the ‘cyclists’ feet on the right are further apart. In this case, placing the feet further apart puts them more under the hips, allowing for a more upright “piston-like” motion while pedaling.

How Do We Fix This?

So how do we fix it so that our knees go straight up and down? Spoiler – only one real way. The right way.
Figure 3- Post fit. This Cat 3 racer’s laser knee alignment at bottom, top and front of pedal stroke.
Two gentlemen came in recently, both having the same issue (knees going out at the top of the pedal stroke) and both were now complaining of newly developed knee pain. Both were fit by the same guy at the same bike shop, and both were fit incorrectly. There are several ways to correct knees moving in and out and most are wrong.
The fitter can:
  1. Wedge the heck out of the shoe by placing numerous wedges between the cleat and the shoe. Placing the thicker side of the wedge along the outside of the shoe will result in canting the knee inward. To see how this works, while seated, place your feet flat on the floor and knees bent at 90°. Lift the outside of one foot and see what happens. The knee dives inward.
  2. Wedging of the insole. This works exactly like #1 above.
  3. Wedging of both the shoe and the insole – this is what the bike fitter did to these 2 cyclists.
  4. Repositioning the cleat to force the heel outwards. To see how this works, sit like in example #1 above. Take one foot and twist the heel outwards while leaving the ball of your foot in place. See what happens? Again, the knee dives inward.
  5. A combination of #3 and #4 above.
Figure 4- Post fit female recreational cyclists knee alignment.
So, what’s wrong with using these methods if it makes the knee track straight? The answer is that you are artificially forcing the knee into a position it doesn’t naturally want to be in. Although that fitter got these cyclists knees to track straight, he introduced such tremendous knee pain for these cyclists that they stopped riding for a couple weeks.
As can be seen in figure 2 above, the only correct way to get knees to track straight(er) is to widen the pedal stance and this can be accomplished in several ways:
  1. Add up to two 1mm pedal washers each pedal. Be cautious since adding more may not allow enough pedal threads engagement with the crankarms. Clients usually require more width but, opt out due to cost and the fact that they are not experiencing knee pain like they were prior to this bike fit (i.e., their knees are now tracking straight up and down or close to it.
  2. Add a pedal extender each pedal (each extender is +20mm).
  3. If you have Speedplay pedals, you can add longer pedal spindles (+3.175mm, +6.35mm, +12.7mm)
  4. If you prefer Shimano, you can opt for their +4mm Ultegra pedals
By widening the pedal stance, the cyclist ends up with correct cleat placement, AND straight tracking knees.

This is for the Pedal Manufacturers!

These statistics will vary for each geographical area, but, for South Orange County, CA. (San Clemente, Dana Point, San Juan Capistrano, Mission Viejo), the pedals that I see during bike fits are 80% Shimano Dura-Ace/Ultegra, 15% Speedplay and 5% LOOK. Twenty miles south in Encinitas (North San Diego County), I am sure that Speedplay is the dominant pedal since (a) Encinitas is the ‘Triathlon capital’ of SoCal and (b) that is where Speedplay headquarters is located.
I have taken the most popular pedals that I see during bike fits and created a table (Table 1) that shows current pedal width and recommended pedal widths. This is based on metrics collected on amount of pedal washers, +4 pedals, longer axles, etc. that I need to add to the cyclists’ stance to (a) keep them where their feet want to naturally be and (b) align their knees as straight as possible.
Table 1- Recommended Pedal Widths to Manufacturers
Comments:
  1. I recommend a wider pedal for the Look Keo Sprint and Keo Classic 3 since these are geared more for the recreational cyclist. A slightly wider platform will be more comfortable for this type of cyclist.
  2. Same for the Shimano 105 FC-R7000

Summary

Based on bike fitting metrics collected, I recommend that manufacturers modify their pedal axle widths to meet cyclists needs. A recommended list is included in table 1 above.

Tuesday, June 12, 2018

What Makes A Good Bike Fitter?


By Rick Schultz

BACKGROUND

Based on a half dozen or so recent client’s ‘bad bike fit’ stories, several asked me to put a short article together on the  topic. I discussed with them their increased risk of injury and that, as they get older, all of those micro-injuries will eventually catch up with them. 
Basically, my belief is that a bike fitter should “do no harm”. This means that if the fitter doesn’t know what they are doing, they shouldn’t be fitting.


WHY GET A BIKE FIT?

Everyone knows that a good bike fit will place you on the bicycle correctly which will allow you to pedal more efficiently (more power to the pedals), help you stay injury free and be safer on the bicycle. And that is my goal for every client. All positive outcomes! But, regardless of how well-intentioned a “bike fitter” might be, a bad fit will rob you of power, and more importantly, increase your risk of injury. I put “bike fitter” in quotes since there are 3 basic types of fitters:
  1. Those who have the education and know that they know what they are doing.
  2. Those who have the education and believe they know but really don’t know what they are doing.
  3. Those who don’t have the education and believe they know what they are doing but they really don’t.

From what I have seen in the industry, the majority of fitters fall into #2, #3, which is sad, since they are actually doing a great disservice to their clients.  

For bike shops there are  consequences to providing a  poor bike fit, sometimes reputation and ultimately their bottom line.  This is where bike shops should take notice!

I recently had two clients come in, both were fit by the same local shop. A third client came in from a second local shop. They came in on different days-“I got a bike fit from shop A, or shop B in this case and I am  in more pain now than I was before I got my [bad] bike fit.” They asked, "what did the fitter do wrong?" I asked them what happened and then I listened intently to what they had to say. All three clients mentioned that during the bike fit, they (1) knew something wasn’t right and (2) told the fitter(s) that they didn’t feel comfortable, and in all three instances the fitter(s) just didn’t listen.

It turned out that all three fits were horribly wrong starting with the cleats. I went through each client’s new fit step-by-step explaining what I was doing and why. I also asked them how they felt during and after completing each step. When we were done, all three  said "WOW, I have no more pain!"

Here’s the part that bike shops really need to pay attention to.  These three clients  began comparing their previous “bad” bike fits to the way I involved them throughout the fit process and they all told me "I'm never going back to that shop again!" followed immediately by "What bike shop do you recommend?"
It turns out that we have a great local bike shop,  G2 Bike. They listen to the client, believe that bike sizing is important, thus ensuring that their clients start off with the correct frame size. They are all about providing real value to the customer. As a bike fitter, this is the type of shop that I want to work with.

So, for those shops that think that they can provide a bike fit from someone who thinks they know what they are doing or worse, what you risk is losing a customer forever...just like these two shops did.

SO, WHAT MAKES A GOOD BIKE FITTER

Here is a great list of questions to use for your potential bike fitter, in no particular order. You can add to this list with your own questions and concerns;
QUESTIONS and RESPONSE(S)
1)      What’s your background?

Not only being a bike fitter, but, being someone who has a background in or understands kinesiology, meaning that the bike fitter will draw on his experience (as to how the body should move) so that they can provide a better user experience. Also, it is useful to be a certified personal trainer or certified strength and conditioning coach, i.e., someone  who knows and understands anatomy. It’s also beneficial to be a USAC or USAT coach and understand physiology. This
 advanced training  and experience  is what you should be looking for in your bike fitter.
2)      What are your qualifications/certifications?

You want to make sure that the bike fitter has related certifications. In my opinion, as a minimum, they should have taken BIKEFIT.COM’s courses. For more advanced training, I believe that the Trek Precision Fit Level 2, 3 / Cyclologic Contact Point Analysis  , the new Guru Range of Right, as well as the  Serotta Cycling Institute Advanced courses  are currently the best bike fitting schools. For those that want to specialize in Triathlon fits, there is  F.I.S.T offered through slowtwitch.com.

3)      How long have you been bike fitting?

Is this your full-time job or side-business? Also, ask the bike fitter how many bike fits they have performed. A good answer would be at least 250 successful and documented bike fits. So, what of bike fitters breaking into the business? I feel there should be an apprentice program set up to help mentor these up and coming fitters.   
4)      Any references, testimonials?

They should have a list of references for you to review. This might be part of their customer  ‘testimonials’ webpage.
5)      Do you ride, do you train?

A fitter who does hard club rides, races and/or trains will understand cycling better and ultimately do a better bike fit for you than someone who doesn’t.
6)      Have you built any bikes? How many? Do you use a torque wrench?

This will indicate their level of understanding in safely swapping out parts on your bike, i.e., their technical skills. Using a torque wrench is mandatory when carbon fiber parts are involved.
7)      Do you fit for local teams or groups?

A fitter who fits for local racing teams and/or cycling organizations  shows that more serious cyclists have trust/faith in this particular fitter. NOTE: The fact that  someone  is/was  a pro or semi-pro  doesn’t  make them a bike fitter.
8)      What is your fitting philosophy? What is your bike fitting process?

Bike fitting philosophy might include stating that they include the clients input as an overall part of a successful process. They also might include discussing how they do cleat fitting, static bike fitting (pros/cons), dynamic bike fitting (pros/cons), what their views are on adjusting the cockpit and even bike sizing might be part of their overall fitting philosophy.
9)      Which bike fit system will I be fit on?

Will this be a static fit or a dynamic fit? Guru, Retul, Computrainer, etc. If so, ask them to give you an overview of the system and how it will be used during the bike fit process.
10)  What is your pricing model?

Question pricing and exactly what you get for the that price? Ask about any upcharges that might occur (i.e., cleats, handlebars, stems, saddles, etc.) as well as any other recommended items other customers end up purchasing whether these be products like pedals and saddles or additional recommended test procedures, such as saddle pressure mapping. Everything done and being charged for should be clearly identified prior to the fit. You basically want to ask, “what am I getting for my money?” and “what other items will I  potentially be charged for?”
11)  If I don’t like the fit/how it feels, do you have a warranty or another plan of action?

What happens on a ‘fit that goes wrong?’ Is there a warranty, is there a possibility of a refund? What will the fitter do to make things right, if they go wrong? This being said, don’t be customer  who pulls this off every time they can.  If so. You are the one committing fraud.
12)  What other services do you offer?

If they are a  USAC certified cycling and/or USAT certified triathlon coach or  a personal trainer, can they  help you gain strength, help  with flexibility, etc. Do they offer any other services such as pedaling analysis, Rotor ring regulation, re-programming Di2, etc.?
13)  What are other potential “add-ons?”

What additional items does your typical fit client end up with? Do they sell items like stems, saddles, handlebars, shoes, insoles, etc.?
14)  Which brands?

Do they carry any brands? Are they locked into one brand such as Specialized? IN my opinion, the first item you pick up might not fit/feel the best so it’s always best if the fitter has several brands to choose from.
15)  Have you published or written any [bike fitting] papers or articles in any related publications?

This should be recommended reading to get a window on what their philosophy is.
16)  Will the bike fit be documented?

Will you get a copy of the bikes new sizing to keep?
17)  How experienced are you at correctly fitting cleats?

Have the bike fitter discuss the cleat fitting process in detail. References should be made to the differences/limitations/strengths on the BIG 4 (SPD-SL, SPD, LOOK KEO, SPEEDPLAY ZERO). Which models offer what (ex., SPD-SL BLUE vs YELLOW, etc.).
ALSO, the fitter should know about pros/cons of wedges, shimming and what different pedal stance widths will do for you and what is available. You want to make sure that the fitter places your feet in a position that will not stress your knees  when you are riding.
18)  How will you correct my knees from going out at the top to tracking straight up and down?

The fitter should be knowledgeable in determining your correct crank arm length as well as be able to explain to you how this is achieved.
19)  Are they knowledgeable with respect to insoles, arch supports, shoes, cleats, etc.?

Ask them about the importance of a good insole, arch support, etc. If you need new cycling shoes, ask them about their recommended shoe, last width, carbon soles, etc.
20)  Do they measure your power output at each step of the fit process?

Your power output should be increasing after each step of the fitting process. Your pedaling stroke should be getting easier and more economical as well.
21)  Do they hold a detailed client interview with you?

At a minimum, they should discuss the following with you.
·         Why you are here for a bike fit?
o   What are the issues?
o   What are your goals?
o   Do you have any injuries, surgeries, etc. that might limit your cycling?
o   How many miles are they currently cycling?
o   How much time can they afford to cycle/exercise?
o   Any other sports?
o   Any other exercising?
o   What is your current lifestyle?
·         For example, a Triathlon/TT fit should put you in a different position depending on length of event.
22)  Do they hold a pre-fit mini-physical evaluation?

At a minimum, the fitter should run you through several tests such as  flexibility , LLD test for Leg Length Discrepancies as well as ask  you to do some pre-fit stretching.

Even though this is a pretty comprehensive list, there might be other items you would like to add for yourself. 

MY QUALIFICATIONS & EQUIPMENT 

 After retiring from IT, I decided to get more involved with my love for cycling. I combined Bike Fitting and USAC coaching. For bike fitting, I started with BIKEFIT’s Foot/Pedal interface course which showed the importance of getting this right. Why? Because this is the only place where you are mechanically connected to the bicycle. From there, I took Cyclologic’s Trek 2, 3 classes followed by Guru Range of Right and Triathlon fit.
Next, I enrolled into USAC’s coaching program and am now a level 2 coach. Next year, I will have time to test for level 1.

Combining this instruction, I have come up with two areas that have been neglected in the cycling industry. A fitter with advanced knowledge would know how to test for and find the correct measurements.
  1. What is the correct crank arm length for you.
  2. What is the correct pedal width for race, club racing and sport road pedals. 

My bike fitting workshop includes a Serotta Size Cycle used exclusively for bike sizing. The workhorse  Computrainer used for the majority of the bike fits as well as a new acquisition GURU DFU bike fit machine that is really a treat to size clients on.
I have the full assortment of bike fitting tools; goniometer, plumb-bob, torque wrenches, 2 motion-based real-time video cameras (used for the GURU fits), and all of the appropriate software to perform every type of fit.  

Rick Schultz is an Associate Cycling Coach in San Clemente, CA with Peaks Coaching Group