A common concern for cyclists is protection of their knees.
If you ride a thousand miles a year that’s over 300,000 revolutions of the
pedals—that is a lot of bending and unbending of your knees! And if
you watch slow motion videos of the legs of people pedaling a bicycle it
isn’t just a simple linear up and down. There is also some gliding,
rolling and rotating involved. Despite the fact that this description
makes cycling sound like it creates a lot of wear and tear on your knees,
orthopedic surgeons often recommend riding a bike or an exercycle for knee
rehab after surgery. To keep mobility and build strength in your knees
they need to move, and cycling provides lots of that movement without the
impact created in walking or running.
Riding a bicycle can actually be good for your knees, as opposed to “wearing
them out”, but there are some important cautions you should keep in mind.
When considering the impact of your cycling on these large and complex joints,
a correct riding position is critical. A general rule of thumb is that a
saddle set too high can cause injuries to the back of your knees, a saddle set
too low can cause problems in the front. Your saddle should be set so
that when your foot is at the bottom of the pedal stroke there remains just a
slight bend to the knee. If you go to straight leg with every
stroke, of if you pedal from a very low saddle position (with your legs
staying significantly flexed during the entire pedal stroke), you are asking
for knee pain. Finally, be certain your bike is the right size for you.
Poorly fitting bikes, ones that are too big or too small for your height,
invite incorrect leg extension, and thus, knee problems.
Do your knees a favor and don’t ride too hard, too soon. When starting
each ride you should not come out of the gate “hammering the big ring”.
Spin comfortably and gently for a bit, get the blood flowing and everything
loose and warm for 10 to 15 minutes before you consider pushing hard. Be
sure to cover your knees in cold weather (under 65 degrees) or they may never
properly warm up (especially if you add wind chill by riding fast).
Also, as a new season begins don’t start out with extremely tough or
extremely long rides. Set up a training schedule that slowly allows all
your body, including your knees, to build up to maximum performance.
Regular heavy duty pressure when pedaling can create deterioration in your
knees rather than a strengthening of them. Numerous runners have
switched to cycling when their leg joints begin giving them problems—cycling
is a wonderful, non-impact, aerobic activity, as long as you don’t use high
pedal pressure and/or very low rpms all the time. Excessive crank
arm length and always staying seated when grinding up hills can magnify pedal
pressure problems. Except for bursts of hill climbing or acceleration
necessary for top performance, think “spin”. Turn the pedals in the
area of 80 to 90 rpms (lots of revolutions, minimal to moderate pressure),
especially when warming up. Maintaining a comfortable, easy pedal
pressure cadence will assure that you are building up rather than tearing down
your knees.
Proper foot placement on the pedals is an important factor in the way your
knees respond to cycling. The best foot placement for you depends a lot
upon your lower limb biomechanics. If you normally are a bit “pigeon
toed” or “duck footed” in the way you walk, then adjust the comments
that follow (in the direction of what your feet do naturally).
Generally, cyclists should avoid riding with their feet angled dramatically
outward or inward. Pointing your feet outward is particularly dangerous
as it inclines your knees to stick out at right angles to the bike, putting
remarkable stress on knee ligaments. If you use clipless pedals, avoid
the old style road pedals with no built-in “rotation” (lateral movement).
As you make pedal strokes, your heels need to be able to shift laterally a
little to allow a “natural” downstroke (allow the gliding, rolling and
rotating mentioned earlier), to prevent undue pressure on your knees.
Finally, the position of the cleats on the bottom of your shoes needs to be
set to your biomechanics. They can be angled a little in or out, if
necessary, to accommodate the position of your feet during your “natural”
pedal stroke, to avoid forcing your knees into “unnatural” positions while
pedaling.
Off the bike, take care of your knees. If you are prone to knee
problems, minimize high impact aerobic exercising, don’t squat or kneel
unnecessarily, and only use low weights for conditioning your legs (especially
when doing leg extensions for building up your quads). If you have
questions about your knees, and especially if you are having significant
problems with them, seek professional advice before beginning a cycling
program. Depending upon your questions or problems, you can consult with
cycling-informed physical therapists, general practice physicians or
orthopedic specialists. Be smart, and enjoy your bike rides!
