Do recumbent bicycles cause knee pain?

Question

I've been thinking about the way the body is positioned on a recumbent bicycle and it seems like knee pain might result. Even if you use a low gearing I think the force direction will always be in a direction on your knees differently from an upright bicycle...

I googled bentrideronline knee pain from recumbent riding and there were tons of results. That seems to be very surprising since recumbent riding is such a small sample of bicycles. Some people were even reporting never having knee pain and then getting knee pain when switching to a recumbent.

I was thinking a recumbent would be the ultimate in comfort but I'm thinking some sort of different geometry upright frame bicycle would be the best between comfort and not getting knee pain.

Answer 1

Ultimately, the cause of knee pain while riding is that we have knees.

That, combined with a poor bike fit will give pain in knees.

The human knee is a relatively vulnerable joint because it is at the end of two shafts and is abutted together while not being constrained as much as a hip or ankle. The elbow is similar.

If you're having knee pain on any bike, think about your saddle height, saddle fore/aft position, foot width apart, and pedal position.

I've seen knee pain caused by a bent pedal shaft, while riding it would follow a "corkscrew" path which aggravated the knee joint most.

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Additionally some knees are just weak. I ride a couple of recumbents, along with two road bikes, a folder, and occasionally a MTB. I always have a dull ache in the right knee no matter what.

Upshot - knee pain is caused by bike fit, or the bike is just highlighting an existing weakness in the knee.

Answer 2

The forces on the legs are not really different between recumbents and upright bikes. In both the seating position should be adjusted for the same leg angles with maximum force applied with an almost extended leg.

On a recumbent the maximum force can be higher because you can press against your back like in a leg press exercise machine (even untrained people can produce surprisingly large forces that way).

On an upright bicycle you have to pull with your arms once your leg force exceeds your bodyweight. This kind of puts a limit on maximum force which might be lower than what your legs could do on their own. For sustained pedaling in the saddle it doesn’t really matter.