10 November 2010

QotD: Neurology question

This month I've decided to post every day. Since I don't have enough original things to write about (hence the desertish nature of my blog lately), I've decided to ask a new question every day this month and hope that I get answers. I have questions; you have answers.

If someone has weakness of the proximal muscles of his legs, does he find it hard to go up stairs or down stairs? Justify your answer. Proximal means "closer to the beginning" and in the case of the leg muscles means thigh and buttocks muscles.

Once enough people respond, I will tell you the answer.


Janiece said...

Um, I'm pretty sure that's why they pay you the big bucks.

Now, if you have a question about erlang load on a VoIP deployment using both H.323 and SIP with situation dependent codec selection, then I'm your gal.


Eric said...

My own experience is that going down stairs is always easier than going up, provided how you arrive at the bottom isn't an issue.

By way of illustration, consider this video: Mr. Arbogast clearly exerts some effort ascending the stairs, both physically and (as you can see) mentally (he is paying a great deal of attention to his ascent), but his descent is seemingly effortless on his part--indeed, he not only easily descends backwards but also has his attention obviously and completely fixated elsewhere.

Of course, I freely confess to only limited, lay medical knowledge, and it may be that the proximal muscles are in fact playing significant-but-different roles in ascent and descent. What's your opinion?

Random Michelle K said...

Going down is harder.

Going down your main support is on a flexed (and hence inherently weaker) joint, causing the your hamstrings and thighs and gluteums maximums to have to take the strain.

Going up stairs, you can somewhat hold your joints in position, and straighten when you have both feet on the same step (assuming one step at a time climbing for safety)

To put it another way, going down stairs, you're reaching to plant your foot while your muscles are bearing the load of your weight. Going up stairs, your foot is already planted and solid, and you can rely somewhat upon both legs for lift and stability.

Plus, you've got the whole mental thing going.

ExpatMom said...

Descending. Just to be difficult.

neurondoc said...

Heh. In a way, this is a trick question. If you read carefully, you'll see that I said "does he find it hard to go up stairs or down stairs", not hardER.

One of the neurologists who trained me during residency asked this question during one of the first neuro teaching lectures I attended during residency. I knew the answer from personal experience, as I have proximal (and distal, for that matter) weakness of my legs, but I let a couple of my fellow residents get the answer wrong first. (Why yes, I am sneaky.)

The correct answer is "Yes" or "Both". It is harder to go UP stairs from a gravity perspective, but going down the stairs is perhaps equally difficult, because of the balance necessary for that action on the pivot point of one leg/knee, as Michelle points out.

Though I like Eric's answer best.