Question about recumbents and bad knees

[Paul]

Hello Everyone,

I have a questions and was hoping that some of you can tell me if I can or
cannot ride a recumbent bike. About 3 years ago I was in a hang gliding
accident which broke my left leg just under the knee and my right foot.
Anyway I'm able to bend my right leg normally but my left leg only has
about a 60 degree bend maybe a little less. I know I can no longer ride the
bicycle I rode before my accident which is a standard mountain bike. My
knee just won't bend past the point to get over top part of the pedal cycle.
Forgive me for not knowing the proper names of the bicycle.

My question is, with a recumbent bike is there any less bending of the knees
when pedaling? Do you have any suggestions I might try to be able to get to
ride a bicycle again?

Thanks,

Paul in NRH, TX

 

[Tom Sherman]

Paul wrote:

> Hello Everyone,
>
> I have a questions and was hoping that some of you can tell me if I can or
> cannot ride a recumbent bike. About 3 years ago I was in a hang gliding
> accident which broke my left leg just under the knee and my right foot.
> Anyway I'm able to bend my right leg normally but my left leg only has
> about a 60 degree bend maybe a little less. I know I can no longer ride the
> bicycle I rode before my accident which is a standard mountain bike. My
> knee just won't bend past the point to get over top part of the pedal cycle.
> Forgive me for not knowing the proper names of the bicycle.
>
> My question is, with a recumbent bike is there any less bending of the knees
> when pedaling? Do you have any suggestions I might try to be able to get to
> ride a bicycle again?

The bending of the knee depends on crank length, but is otherwise
approximately the same for both uprights and recumbents. With very short
cranks, the amount of knee bend might be within your limit.

Very short (e.g. 110-mm) cranks can be created by drilling new pedal
eyelets in regular cranks and machining off the ends.

--
Tom Sherman – Quad City Area

 

[Doug Huffman]

Efficient pedaling is the same whether recumbent or upright. If an
asymmetrical stroke can be tolerated then there are various systems for
adjusting the length of the cranks, as for particularly tall or short
riders. One of these could be used on your customary bike.


"Paul" <[email protected]> wrote in message
news:[email protected]...
| Hello Everyone,
|
| I have a questions and was hoping that some of you can tell me if I can or
| cannot ride a recumbent bike. About 3 years ago I was in a hang gliding
| accident which broke my left leg just under the knee and my right foot.
| Anyway I'm able to bend my right leg normally but my left leg only has
| about a 60 degree bend maybe a little less. I know I can no longer ride
the
| bicycle I rode before my accident which is a standard mountain bike. My
| knee just won't bend past the point to get over top part of the pedal
cycle.
| Forgive me for not knowing the proper names of the bicycle.
|
| My question is, with a recumbent bike is there any less bending of the
knees
| when pedaling? Do you have any suggestions I might try to be able to get
to
| ride a bicycle again?
|
| Thanks,
|
| Paul in NRH, TX
|
|

 

[Ian Smith]

On Sat, 31 Jul 2004 21:53:35 -0500, Tom Sherman <[email protected]> wrote:
>
> The bending of the knee depends on crank length, but is otherwise
> approximately the same for both uprights and recumbents. With very short
> cranks, the amount of knee bend might be within your limit.

Alternatively, there are special solutions that substitute a more
complex mechanism in place of one crank, which gives a non-cirular
pedal path. Some of these can give near full-size crank effect round
the lower part of the down-stroke, while not lifting as high at teh
top of teh stroke. There's some power penalty, and a complexity &
cost penalty, but they can give a better solution to limited mobility
joints than simply drastically shortening a crank.

Unfortunately, beyond knowing such things exist, I don't know much
useful about them (like how you might obtain one). I suspect you'd
need to start with a medical type - possibly a physio might know where
to find this sort of thing.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

 

[anonymous coward]

On Mon, 02 Aug 2004 20:03:46 +0000, Ian Smith wrote:

> On Sat, 31 Jul 2004 21:53:35 -0500, Tom Sherman <[email protected]> wrote:
>>
>> The bending of the knee depends on crank length, but is otherwise
>> approximately the same for both uprights and recumbents. With very short
>> cranks, the amount of knee bend might be within your limit.
>
> Alternatively, there are special solutions that substitute a more
> complex mechanism in place of one crank, which gives a non-cirular
> pedal path. Some of these can give near full-size crank effect round
> the lower part of the down-stroke, while not lifting as high at teh
> top of teh stroke. There's some power penalty, and a complexity &
> cost penalty, but they can give a better solution to limited mobility
> joints than simply drastically shortening a crank.
>
> Unfortunately, beyond knowing such things exist, I don't know much
> useful about them (like how you might obtain one). I suspect you'd
> need to start with a medical type - possibly a physio might know where
> to find this sort of thing.

I have no experience of these things either, but there was something on
bentrideronline recently that sounds similar - though they don't give
details about the pedal path:

http://www.bentrideronline.com/2004Feb/rotor_cranks.htm

Random (and possibly daft) thoughts include that:

Clipless pedals might help because they let your good leg pull your bad
leg round the circle, and because by moving the cleat between your toe and
your heel you may be able to adjust the amount your knee needs to bend.

Is there any reason not to use one long crank (for the good leg) and a
much shorter / childrens crank for the bad leg?

Could you put a platform on one pedal, but not on the other?

Good luck,

AC

 

[Tom H.]

A man in my town has a trike that is operated by hand power. he rides
all over. He uses it because of some leg problem which does not allow
him to ride a conventional bike.

That might be an option if the other solutions do not work that have
been suggested here.