Bicycle-related pain and injuries are commonly associated with poor bike fit. If you have pain related specifically to cycling, you might have a bike fit problem.
Bike Fit Basics
Keep a controlled but relaxed grip of the handlebars.
Change your hand position on the handlebars frequently for upper body comfort.
When pedaling, your knee should be slightly bent at the bottom of the pedal stroke.
Avoid rocking your hips while pedaling.
Problems and Possible Causes:
Anterior (Front) Knee Pain
Possible causes are having a saddle that is too low, pedaling at a low cadence (speed), using your quadriceps muscles too much in pedaling, misaligned bicycle cleat for those who use clipless pedals, and muscle imbalance in your legs (strong quadriceps and weak hamstrings).
Possible causes include poor handlebar or saddle position. A poorly placed handlebar might be too low, at too great a reach, or at too short a reach. A saddle with excessive downward tilt can be a source of neck pain.
Lower Back Pain
Possible causes include inflexible hamstrings, low cadence, using your quadriceps muscles too much in pedaling, poor back strength, and too-long or too-low handlebars.
Possible causes are inflexible hamstrings, high saddle, misaligned bicycle cleat for those who use clipless pedals, and poor hamstring strength.
Hand Numbness or Pain
Possible causes are short-reach handlebars, poorly placed brake levers, and a downward tilt of the saddle.
Foot Numbness or Pain
Possible causes are using quadriceps muscles too much in pedaling, low cadence, faulty foot mechanics, and misaligned bicycle cleat for those who use clipless pedals.
Iliotibial Band Syndrome (ITBS)
Possible causes are too-high saddle, leg length difference, and misaligned bicycle cleat for those who use clipless pedals.