Do you think a hollow stone surface carved out in the exact shape of your body would be as comfortable to lie on as a mattress?

Of course not. Who the heck doesn’t move – at all, ever – while sleeping?

well at first i guess it would feel good, but think aboutit, not moving your body all night your going to wake up really sore

I move way too much for that to be comfortable. Also, I like soft cushy beds.

Yes. I work in a clinic that does highly customized seating for wheelchairs. We have to produce surfaces that people can sit against, often without moving, for many hours. It’s all about distributing the weight over as large a surface area as possible. The resiliency of the surface only matters when movement is involved. We often end up taking an impression from the person’s body and making a surface that conforms perfectly to their contours. One famous rehab clinic actually uses a stiff, hard plastic for its molded seating.

I move a lot during sleep. My husband doesn’t, so it might work for him, but I think the back of your head would be sore from resting on a hard surface for so long. I just think of how the back of my head feels after sitting at a movie with my head leaned back against the hard plastic trim at the top of the seat.

@MrItty, @rhector63, @casheroo:
I intended not to consider the factor of moving in your sleep, for the sake of discussion.

@Harp: does the customized seating work similar to the kind of molded braces for teeth where the body shape eases into a better position for posture and weight? Are these custom chairs covered under most insurances and if not, how much do they usually run? I have a particular friend who could benefit greatly from something like this.

Then there’s gravity.

@Fyrius
Oh okay, so yeah if you didn’t move then that would probably work for like relaxing or something

@Supacase: You forgetting that you’re thinking of a hard surface, flat, your weight resting on only one small spot. If it were exactly in the shape of your head instead, don’t you think it would be different?

@Judi: People on mattresses don’t seem to mind gravity. Why would a rigid bas-relief stone mould be different?
Like I said, I think the reason why mattresses make gravity unproblematic to comfort is because your weight is distributed. The stone bas-relief mould should have the same effect.

have any of you guys ever lied down on a water bed?

I owned a waterbed back in the day when they were sloshey. It was really hard. Not comfortable at all.

I move when I sleep. No go.

As for waterbeds, I’ve slept on one before. It’s on the other end of the spectrum because it moves way too much.

oh thanks @Judi, i was actually gonna buy one a few weeks ago but they turned out to be REALLY expensive

As a semi-related remark, have you ever felt the surface of flour?
Imagine a water bed filled with that.

@hungryhungryhortence Sometimes the shape may be designed to correct an unhealthy tendency in a patient’s posture, but more often the goal is simply to accommodate as well as possible their natural shape.

We sometimes use a device called a “pressure map”, a thin sensor array that we slip between the patient and the cushion. It senses pressure over the entire seating surface and displays it as a multi-colored map. This lets us see where the “hot spots” are, and we can modify the surface until they go away. Immobile people with sensitive skin can develop life-threatening pressure sores if the distribution isn’t close to perfect.

I’m not sure about your insurance question, since almost of our clients are covered by public aid (we’re a state-run clinic). This kind of seating is extremely expensive though; thousands above the cost of the chair itself.

@Harp: thanks! I’m going to pass this on

My husband had a waterbed when I moved in. I hated having the bed follow me around. Couldn’t wait to get rid of it. Also when the power went out, man, was it cold and clammy. Who needs a bed that plugs in? Besides, it was a pain to make up. We eventually sold it to a happy young woman and bought a conventional bed.

I would not want to sleep on anything that locked me into one position. I don’t have a comfortable position any more. I spend the night swapping pain here for pain there, about every two hours.

oh, thanks @Jeruba
Now i know

I love my Tempurpedic. It is a bit firmer than I am used to, but once I got used to it I love it. I don’t move around as much in my sleep anymore either.
@Jeruba; Remember having to get on your hands and knees just to roll over?

you know what someone should make a bed out of, Gel, like the soft but firm Gel

@Harp: Oh wow, a professional buttockogram.
The things science can do these days.

I like firm mattresses
like I like my um…too early to think about that

@Fyrius Would you also like to not consider the effects of heat when discussing the Sun? You can’t talk about being comfortable while sleeping without talking about motion. They are too interconnected.

@Judi, I remember pushing off from the frame. I also remember not being able to get up very fast (couldn’t live with that now!). And as I recall the cats were justly suspicious of it.

@MrItty: Who mentioned sleeping? I was just talking about it being comfortable to lie down on.

Yes. It would offer perfect support (assuming you don’t move) and would feel good, but for a short while. The Thermal Conductivity of rock is much higher than cloth and would quickly draw heat from your body. The thermal conductivity of sandstone is 1.7W/mK, cement mortar is 1.73 w/mK, and Quartz is 3.0! Cork on the other hand is 0.07W/mK, Felt 0.04, Air is 0.024 W/mK. We’re talking about a factor of 100! If you heated the rock, you’d be ok – until you decided to move.
@Harp Are your surfaces heated?.

@Lupin No, cooler is better for preventing skin breakdown.

Water is 0.58 W/mK . That’s why an unheated water bed feels so clammy. A rock would be 3x worse!
(I’m such a geek.)

@Lupin Thanks for being such a geek. :D

@Harp I’ve used pressure films under gaskets. I never thought to use it for a buttockogram. Who knew?

@Fyrius I can’t help it. I just cannot resist a good physics question.

@Lupin Don’t fight it. Give in to your geekiness. It is your destiny.

(Cue Darth Vader theme)

seems like an expensive way to not enjoy yourself.

@Lupin – I think you sound like a great person to have as a best friend, you are always prepared and you always seem to have a reasonable response.

Shoot, I forgot to answer the question, it sort of reminded me of the orthotics in my shoes. They are rigid and make my foot the way it should be, but don’t feel as nice as the cushy innersole of the running shoe.

Movement and heat would be the kickers with a custom molded stone bed. I just saw a movie though, The White Masai, where they slept on their backs with their head in a sort of tripod type thing made out of tree branch, looked really uncomfortable and I guess Masai men don’t move when they sleep???

The reasoning behind this question is actually sound if short-sighted. The basis for bed sores and people waking up tired and in some cases sore is that some matresses which rely heavily on springs will provide a measure of full body support but will put greater pressure on specific points on the body hence creating either the sores or some form of discomfort.

Newer technologies like Tempur pedic for example will distribute weight and tension evenly over the entire contact surface thereby eliminating pressure points and providing a more restful night’s sleep.

Theoretically a bas relief stone surface (otherwise known as a SARCOPHAGUS) could provide the same measure of support if made in the exact contour of the person’s bdy and if said person had zero weight and size fluctuation… the flaw here is that weight will fluctuate with everything from water consumption to meal size and frequency… and size will vary depending on the time of day, level of activity and however long one has been in a resting position.. you lose a small ammount of height during the day because of the effects of gravity and your own weight pressing down on your body.. you gain it back over the course of a night’s sleep when your body no longer fights gravity in a vertical sense and can stretch to it’s full height without resistance.

So sound theory… but not practical.

Again, I wasn’t intending it to be practical, either, nor did I mention sleeping on it. It’s just a pointless hypothetical question.
Other than that, good answer.

Dr. C… where have you been all my life?

@ABoyNamedBoobs03 fighting evil… and trust me, i look GOOD in tights and a cape.

lol epic

I haven’t been around in a while, have I missed anything of worth?

@ABoyNamedBoobs03 besides the slow agonizing death of campfire not much. There will be a fluther wedding (proposal made on the site)... other than that not a whole lot… no flame wars (none worth mentioning anyway)... same old same ol. Glad you’re back! you should come on chat!

yeah I heard it’s been falling off the wayside. I see there’s still the same punching bags hanging around. I’d come on chat but I lost the link… new computer and such.