Viewing 13 posts - 1 through 13 (of 13 total)
  • Armchair physios assemble: why does my knee hurt?
  • Premier Icon thenorthwind
    Full Member

    I’ve got a pain in my right kneecap. The best way I can describe it is my kneecap feels like it’s moving around on top of the joint. It hurts to put any power through that leg on the bike, and a bit when I walk (particularly up stairs).

    The back story:
    Not had this sort of pain before.
    Went for a bike fit 3 weeks ago. Saddle moved forward and down very slightly, not so much to correct the distance to the pedals, but to angle it slightly differently to correct for the fact that my left leg is very slightly shorter (have had some problems with left hip before too).

    Did a 200km audax two weeks ago (acid test for a bike fit!). New position felt comfotable, but developed this knee pain. Quite painful after.

    Not much significant riding (just 8 mile round trip commute + getting around town) since, but went for a social paced, flat-ish 60 mile ride yesterday. Now it hurts again.

    The obvious answer is the new position from the bike fit has caused the knee pain, but want to know what the likely cause is (in terms of particularly muscles/tendons) to see whether there might be another solution other than just going back to my previous position. And not jump to conclusions – could be coincidence and a 200km ride would have brought it up anyway. Anyone have any similar experience? Advice?

    I should point out than I’m happy with the service I’m getting from the bike fitter – old hand, came recommended unanimously by the roadies in our club. I told him about the knee pain immediately after the audax, and he suggested giving it a little bit longer, and that it could just be adaptation to the new position. I’m sure he’ll suggest what do if it persists.

    Premier Icon chiefgrooveguru
    Free Member

    It sounds like your patella is mistracking. I’ve had this due to having a badly damaged ankle which no longer works properly putting unusual load onto the knee. Building up leg strength through the full range has pretty much solved it.

    Premier Icon senorj
    Full Member

    It’s one of the early symptoms of cat aids. A physio may be able to save the leg at least.

    Premier Icon qwerty
    Free Member

    Whole lot of elements to consider the many causes….

    For me, old knackered Time pedals & old knackered worn shoes seem to have been the cause.

    First thing I did was buy some Shimano PD M520 pedals for £20, those alone made it go away, then new shoes (Terraduro) made my point of contact at the pedal a whole lot more solid.

    Easiest way to describe it was that before it felt like I was pushing down on an unstable pin point, now i feel like I’m pushing down on a much bigger & more solid platform.

    Not saying that’s what your is, but it seems to have been for me.

    Premier Icon qwerty
    Free Member

    PS: if you know that one legs shorter than the other, should some cleat spacer / shoe insert not be used to even things out???

    Premier Icon greenskin
    Full Member

    I had a similar pain, turns out my it band was mega tight in my right leg, when I bend down or run the pain manifest in my knee due to it being pulled out of alignment. Or something like that.

    Premier Icon thenorthwind
    Full Member

    Sorry, probably should have mentioned: I use flats on all my bikes. Bike fitter was confident that because I’d been riding flats for so long, my feet naturally find a good position on the pedal.

    He did mention that he had a guy who had one leg 8mm shorter than the other (which is a lot apparently) and that the only way to fix that was with a spacer.

    Premier Icon Fat-boy-fat
    Full Member

    Could be your ITB is super tight and pulling on your knee cap. I get that a lot and feels like you describe. A good quad and ITB sports massage might help.

    Premier Icon n0b0dy0ftheg0at
    Free Member

    Check the angle between your hip joint, knee joint angle and normal position of ankle joint at bottom dead centre of pedal stroke.

    It should be 25-35 degrees for most riders. Every 1mm of saddle height change affects that angle by 1 degree.

    When I changed to 3-bolt pedals last year, I tweaked my saddle position and got sharp pains on my outer left knee a few days after a hard ride. I had to stop power intervals for ~8 weeks, turned out I hadn’t aligned cleats decently for my bow legs and my knees didn’t like ~25 degree bend. Lowering ~5mm made all the difference.

    Premier Icon Onzadog
    Free Member

    After one person said I had a let length discrepancy, someone else told me that unless they hung me upside down and x-rayed me, they couldn’t actually know that for sure. It could just be a tightness on one side.

    Premier Icon enigmas
    Free Member

    Lowering and moving the saddle forward does increase load on the patellafemoral joint. I’d be tempted to rest up for a week or so then try the old position to isolate the bike fit.

    Again for leg length, most of us have up to 10mm of discrepancy without issue. Cleat spacers can help with this though, rather than trying to change other things.

    Another one is cleat position can easily cause maltracking of the patella.

    Premier Icon thenorthwind
    Full Member

    Check the angle between your hip joint, knee joint angle and normal position of ankle joint at bottom dead centre of pedal stroke.

    It should be 25-35 degrees for most riders. Every 1mm of saddle height change affects that angle by 1 degree.

    When he initially measured me up I was bang on 30° on the right and 28.5° on the left. Can’t remember what it was after the adjustment. The idea was to even the angle up as I was naturally adjusting for it in my foot position, which could apparently cause problems.

    I’d be tempted to rest up for a week or so then try the old position to isolate the bike fit.

    This is probably the answer. Don’t have much riding planned, but am planning to walk 15 miles carrying a packraft and bivvy kit at the weekend. Hmmm.

    Premier Icon globalti
    Free Member

    I don’t think youmention your pedals and cleats but if you ride with a foot up against the limit of cleat movement, the very small twisting force can really mess up your knees.

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