10 ms·

What Is Suspension Trauma a.k.a. Harness Hang Syndrome?

141 points by mhb 8y ago

newmac 8y ago
I am currently building a house, and there are large portions of it that have a >25ft drop from rooftop to the ground below. That means the workers on the roof or upper floor need to wear proper fall protection. Depending on the job that can often by a harness system. I was surprised that because of the height of the potential fall, we needed a "rescue plan". In other words: arresting the fall is only half the job. The result was quite a bit of extra expense for us (because of the site conditions, we need to keep a hydraulic lift available), but when I read about how quickly suspension trauma becomes an issue, I could understand why the safety regulations are written as they are.
- planteen 8y ago
  That's why you would never catch me on a rope without at least a pair of loops of smaller diameter rope that I could tie into Prusik knots and self-rescue. Those pieces of rope are almost weightless. There's no reason not to have a pair with you when you get on rope.
  - maxerickson 8y ago
    Featured in a James Bond stunt: https://www.youtube.com/watch?v=8FDX6_BSas8 https://www.youtube.com/watch?v=8FDX6_BSas8 (The clip is from "For Your Eyes Only" but has music from some other bond film dubbed over it)
    - TeMPOraL 8y ago
      Wow, apparently you can pull yourself up by your own bootstraps!
  - mirimir 8y ago
    Why not tie an Alpine Butterfly in advance? Isn't that more secure than Prusik or Klemheist? Or does it weaken the main rope too much? Or are you saying to use a pair of Prusik knots to self rescue, by climbing the rope?
    - JshWright 8y ago
      Yeah, the parent comment is talking about using a pair of Prusiks to ascend (or to at least make loops you can use to stand). An Alpine Butterfly can't be moved, so it's not especially useful in many applications.
      - planteen 8y ago
        Yep exactly. I'm talking about a pair of Prusiks to climb the rope. Of course ascenders/Jumars are even better. :)
        mirimir 8y ago
        Thanks. So when I was a kid, they made us climb a ~3 cm rope about 20 meters. With no aids, and just a padded mat for protection.
        JshWright 8y ago
        20m? That's a fatal fall...
        mirimir 8y ago
        OK, upon reflection, more like 8-10 meters. The ceiling height in the gymnasium. It was a long time ago, and what I mostly remember is the fear of falling. And the rope burns.
  - takk309 8y ago
    Try getting a prusik system set up when your tie in point is in the middle of your back as most construction harnesses are set up. It makes it much harder to self rescue. Side note, one of my favorite ways to get up a rope when hanging in free space is to walk the rope. https://www.youtube.com/watch?v=gAzXYVdskFE https://www.youtube.com/watch?v=gAzXYVdskFE
    - module0000 8y ago
      Also, in those times when you need a prusik, there is a less-than-tiny chance you are hurt. EG: you're trying to place your cam, and instead you take a 40 foot drop before your last cam arrests your fall by sending your body directly into the face. Prusiks are more difficult to tie(and ascend!) when your hands are coated in your own blood, etc.
      - takk309 8y ago
        I have, thankfully, never had to try to tie a prusik with my hands covered in blood. If you had to do that, it sounds like a brutal fall.
      - planteen 8y ago
        Yeah for sure, injury changes things. You see rock climbers needing rescue often enough when they could have self-rescued by a pair of Prusiks and ascending the rope. I've heard of a rock climber using an ATC (rappel device) as an ascender, by kicking off the wall and moving the rope up a few inches. They were near complete exhaustion when they got up to the top - Prusiks would have made the job so much easier. Of course a pair of ascenders/Jumars is best, but add some weight. Most people (outside of cavers) don't plan on climbing up a rope with single rope technique, so it's not something that is practiced very much. I'm not really sure why. I'd be super nervous as a climber if I only could go one way on a rope. I guess alpinists practice it some for self-rescue out of a crevasse. Cavers use the rope as a nylon highway, so you know how to switch from rappel to climb, climb to rappel, and how to pick-off an injured party from the rope (all of those in space, where you can't take your weight off the rope at all).
- Bartweiss 8y ago
  It's always surprising to me how fall risks operate in the world of OSHA compared to rock climbing. There's an entire domain where people take good-sized falls as an everyday event, just sort of sitting in parallel with the domain where they're considered a major risk needing emergency-response measures. Obviously, some of that is a real difference in situation. Construction falls are unplanned and happen under all sorts of odd circumstances, and people are quite often injured during their falls. Climbers have someone managing the other end of their rope at all times, on a system that makes lowering them to the ground straightforward. But other differences seem absolutely pointless. The "suspended by your groin, legs hanging straight down" posture of construction harnesses massively accelerates suspension trauma, while climbing harnesses pull the legs up and keep pressure on large muscles. And there are companies starting to use that design for safety gear, so it's not a regulatory issue - it just somehow took decades to cross the gap.
  - takk309 8y ago
    I big difference between a climbing harness and a construction harness is the tie in point. Climbing it is fine to have that point in front of the user. For construction, having the rope constantly in front of you would be a real inconvenience. By tying in on the back, the harness will hold the user in a different orientation just due to the way weight is distributed.
    - Bartweiss 8y ago
      That's definitely part of it; climbing harnesses tend to support you in a position that's great for suspension trauma, but involves a pretty inconvenient rope. They're also waist-and-hip only, and while they'll reliably hold a climber through a flip, it doesn't sound great for chaotic, confined-space falls where you might stay upside down. The newer generation of construction harnesses are still back-clipped and full-body though - a short strap runs from the waist to the back clip to redistribute weight without normally being in front of you. Presumably getting that working smoothly and safely was an extra engineering hurdle, but I'm still surprised harnesses went so long without even including waistbands.
  - module0000 8y ago
- burfog 8y ago
  Falls from far less than that height can kill. If it is safe to be at 10 feet without that equipment, then it is safe to be at 1000 feet without that equipment. IMHO, the cutoff is just what the construction industry was willing to tolerate. The whole thing is a lobbyist battle between the construction industry and the safety equipment industry.
  - newmac 8y ago
    I think that at a lower height, a rescue is considered to be easier. 10 ft would still require a safety program, it just wouldn't be fall arrest, more likely prevention (scaffolding)
yodon 8y ago
A similar root cause issue is developing life threatening blood clots from sitting too long. Both suspension trauma and blood clots in the legs come from a clever optimization of our circulatory system. The heart can't actually pump blood out of the legs. It counts on muscle activity to make the flow happen. If you sit for many hours, like on a cross country or cross ocean flight, or because you are a dev or gamer with tremendous concentration and focus, the blood quite literally just sits in your legs and eventually starts to coagulate. It doesn't matter how much exercise you get the rest of your day, those 6 or 8 hours of sitting can quite literally kill you through the creation of a blood clot that then flows through your system and blocks blood flow to the heart or brain (all learned personally when I developed such a clot from routinely sitting long hours in a coffee shop with my laptop and 100% focus). If you're like me and can focus easily for many hours straight, get a Fitbit, turn on activity tracking, and when it tells you you haven't walked around recently get up and walk around. It's much less impactful to your concentration than an emergency ER visit followed by a lifetime of prescription blood thinners to reduce the now much higher risk of a second clot.
- tyingq 8y ago
  "Deep Vein Thrombosis" is the term if anyone is looking for more info. https://www.cdc.gov/ncbddd/dvt/travel.html https://www.cdc.gov/ncbddd/dvt/travel.html
  - mrkstu 8y ago
    Yep, flew from Phoenix to Atlanta, fell asleep until the end of the flight, woke to get off the flight, and immediately became blind in one eye as an embolism blew up inside the vitreous fluid. Not a great way to start a new job. Boss was meeting me at the airport thankfully and he drove me to the hospital to get checked out. A few weeks of an eye patch was the short term outcome and a bunch of new 'floaters' that my mind has mostly learned to filter out. Just very grateful that it detonated in my eye instead of my brain...
    - tyingq 8y ago
      The link I posted mentions it's not just air travel, but car, train, bus, etc, also. But I have to wonder if the shrinking coach seat pitch/size isn't a big factor. I'm fairly average size, but flying is miserable these days. Perhaps also the relative awkwardness of getting up while flying...the visible sighs from your row mates that have to move around a lot to let you pass.
leoc 8y ago
Yeah, interesting timing. It also seems quite similar to the effect of high (downward) G-forces.
hprotagonist 8y ago
Whenever i'm climbing outside i have a few lengths of dyneema or cordelette that i can rig into a prussick or kleinheist for self-rescue or for staying comfy at multipitch belays that don't have nice ledges. I don't hangdog all that much, so i was actually unaware of this risk, but it's worth keeping in mind!
- oftenwrong 8y ago
  Dyneema is not the best choice for friction hitches due to its low melting point. This is primarily a concern when using it as a backup for abseiling or lowering, or in any situation where you may take a fall onto the friction hitch.
  - hprotagonist 8y ago
    I know. I don't use it for raps, but it's just fine as a static or static-ish anchor.
- takk309 8y ago
  This is less of a risk in a climbing harness due to the location of the tie in point. With the point in front of you at your waist, it is possible to shift your legs around even when free hanging. Think about doing a rappel on a long free hang. For me, I keep my legs in front of me and more or less above my waist. If you were tied in at a point on your back, as construction harnesses use, your center of mass is below the suspension point and the only position you can grab the rope is with your arms above and behind your head. Try doing a pull up in that positions, it is extremely hard.
  - planteen 8y ago
    I once was indoors as a "training dummy" who got stuck on-rope rapelling and waited for someone to come up from the bottom to pick me off. My "tie in" point was a rack at my waist on the front. It takes a while to do this as it's not easy to climb past someone in single rope technique. I definitely felt my legs starting to go numb, even when I was kicking them around to keep blood flowing. I was hanging in space. That experience hit home to show the reality of harness hang syndrome.
QuotedForTruth 8y ago
Its interesting to me as a rock climber that I've never heard of this. Its not unusual for someone to hang in their harness at an anchor for quite a while while their partner is climbing the pitch before and after. Are climbing harnesses that much more comfortable than safety harnesses that its not a problem?
- planteen 8y ago
  It will still happen in a climbing harness if you are hanging in space. On a hanging belay, you try to get your weight off the harness and get your weight on your feet on the wall as much as possible. This alleviates the problem. Cavers will spend a long time hanging in space on rope when climbing out of deep pits (over 100 meters / 300 ft) with single rope technique. That doesn't lead to harness hang, because you are engaged in aerobic activity with your legs.
  - QuotedForTruth 8y ago
    That is true. A free hanging belay would not be very useful! I did find some discussion on mountain project about it in the context of rescuing an incapacitated climber.
- ska 8y ago
  I think the lack of movement (especially if unconscious or barely conscious) and full suspension is key. When climbing, do you typically maintain contact with the wall, especially with you feet?
  - QuotedForTruth 8y ago
    Barring injury, you wouldnt be hanging in free space for very long. I didn't realize that would make such a difference. After my comment I did some more searching and found plenty of discussion of harness hang syndrome in the context of rescuing an incapacitated climber though.
- JshWright 8y ago
  Are you typically hanging with all your weight in the harness, or are you leaning off the wall?
deleted 8y ago
[deleted]
amelius 8y ago
This is the stuff I think about when I find myself in an overly tight airline seat.
- brandon272 8y ago
  I am constantly and intentionally contracting my leg muscles when in an airplane. Mainly due to comfort issues, but I figure it is probably also helping blood flow.
reubenmorais 8y ago
Last time I went skydiving I experienced something like this. I was doing a pair jump and you do it in a harness that’s attached to the skydiver with the parachute. When the chute opens you slide down/into the harness and it compresses around your thighs. The first time I jumped, the instructor told me to step on his feet so he could put some slack in the harness, but this time the instructor didn’t do that, so for the whole time between opening the chute and landing I was stuck motionless in the tight harness. I almost passed out, it was pretty scary.
dangerboysteve 8y ago
This happens also to hunters that fall from hunting in tree stands and are wearing a safety harness.
quacked 8y ago
About a year ago, I was flying a hang glider and accidentally had a parachute deployment, and I ended up suspended in a tree, waiting for a grounds crew to come cut me down. The first thing that my friend said when I called him was "stand up if you can". Suspension trauma is a real risk for pilots who get stuck in trees, and it's a subject covered during parachute education clinics for that reason.
aasasd 8y ago
> as you inhale, the mediastinal intrapleural pressure becomes more negative, leading to expansion of the lungs, and pressure drops in the RA, RV, SVC, and IVC. Right Atrial expansion increases the pressure gradient for venous return So you're saying my lung volume has implications for the chance of deep vein thrombosis or possibly even for varicose veins? Great engineering right there.
BXLE_1-1-BitIs1 8y ago
A climber can reach the rope, put in a prussik and stand on it. No can do with construction harnesses. The rope's out of reach.
- ken 8y ago
  There are products available which enable one to self-rescue from a lanyard at your dorsal.
deleted 8y ago
[deleted]
grahamburger 8y ago
Interesting to see this pop up here! I'm in the process right now of getting my team Tower Safety Certified by Comtrain and this is one of the things they learn about. They also have to practice both being rescued from a tower (while hanging limp as though they were unconscious) and rescuing someone else from a tower. Gotta stay safe out there!
- velosol 8y ago
  Given the address in your profile I'd suggest you might also want to have your team have access to non-cell communications. Sometimes you're at a tower that doesn't have great cell reception and even if the team is able to rescue an injured member they won't be able to safely transport them and be stuck sending someone to find cell coverage and call for an ambulance.
  - grahamburger 8y ago
    That's very true! Fortunately in our case (at least with the company I work for currently) we don't do any work outside of cell coverage or more than a few miles from a hospital. Part of the tower safety process though is to decide before climbing the tower where you will take someone if they get injured and how you'll get them them, or who/how you'll call if they can't be transported.
bitL 8y ago
Is this somehow related to feeling uneasy from skydiving once parachute is deployed as well? I sometimes feel like I am going to pass out. I had a scary situation while practicing multiple tailspins and free-falls on a sailplane and almost blacked out after the last one (basically couldn't feel anything and landed just by vision and mechanical yoke movements I couldn't feel at all.
DoctorMemory 8y ago
I started looking into a suspension system for Virtual Reality to increase immersion. I thought it was surprising that no one had made a harness type device. Then I came across suspension trauma and realized how complex an issue it would be to make something like that and take it public.
I_complete_me 8y ago
Coincidence or what? I attended a Safety Course (Construction) this very day and was introduced to the term orthostatic trauma which is also called suspension trauma. It so happens that I also do tree climbing with ropes and am familiar with prusik knots for ascension. Everyone should experience the sensation of climbing a single rope - it is magic. And finally I suffered bilateral pulmonory embolisms that I am putting down to excessive sitting while developing. My consultant told me that "20% don't make it to hospital"! Chilling memories. This article struck me thrice.
mindgam3 8y ago
Wow, I had no idea this was a thing. I nearly blacked out the first (and only) time I went skydiving. Tandem jump with instructor. Free fall was fun. After parachute deployed the harness started feeling tight around my chest and legs. I got dizzy and it felt like I was having a panic attack, difficulty getting enough oxygen. When we landed I immediately fell to the ground where I couldn’t get up for a few minutes. My friends who jumped with me were all laughing and having a great time, they thought I was being dramatic or something. A web search brought up tons of hits of this being discussed in skydiving forums. Apparently it’s related to older harnesses. Some skydivers don’t believe it’s real. Thanks for posting this.

141 points by mhb 8y ago

I am currently building a house, and there are large portions of it that have a >25ft drop from rooftop to the ground below. That means the workers on the roof or upper floor need to wear proper fall protection. Depending on the job that can often by a harness system. I was surprised that because of the height of the potential fall, we needed a "rescue plan". In other words: arresting the fall is only half the job. The result was quite a bit of extra expense for us (because of the site conditions, we need to keep a hydraulic lift available), but when I read about how quickly suspension trauma becomes an issue, I could understand why the safety regulations are written as they are.

planteen 8y ago
That's why you would never catch me on a rope without at least a pair of loops of smaller diameter rope that I could tie into Prusik knots and self-rescue. Those pieces of rope are almost weightless. There's no reason not to have a pair with you when you get on rope.
- maxerickson 8y ago
  Featured in a James Bond stunt: https://www.youtube.com/watch?v=8FDX6_BSas8 https://www.youtube.com/watch?v=8FDX6_BSas8 (The clip is from "For Your Eyes Only" but has music from some other bond film dubbed over it)
  - TeMPOraL 8y ago
    Wow, apparently you can pull yourself up by your own bootstraps!
- mirimir 8y ago
  Why not tie an Alpine Butterfly in advance? Isn't that more secure than Prusik or Klemheist? Or does it weaken the main rope too much? Or are you saying to use a pair of Prusik knots to self rescue, by climbing the rope?
  - JshWright 8y ago
    Yeah, the parent comment is talking about using a pair of Prusiks to ascend (or to at least make loops you can use to stand). An Alpine Butterfly can't be moved, so it's not especially useful in many applications.
    - planteen 8y ago
      Yep exactly. I'm talking about a pair of Prusiks to climb the rope. Of course ascenders/Jumars are even better. :)
      - mirimir 8y ago
        Thanks. So when I was a kid, they made us climb a ~3 cm rope about 20 meters. With no aids, and just a padded mat for protection.
        JshWright 8y ago
        20m? That's a fatal fall...
        mirimir 8y ago
        OK, upon reflection, more like 8-10 meters. The ceiling height in the gymnasium. It was a long time ago, and what I mostly remember is the fear of falling. And the rope burns.
- takk309 8y ago
  Try getting a prusik system set up when your tie in point is in the middle of your back as most construction harnesses are set up. It makes it much harder to self rescue. Side note, one of my favorite ways to get up a rope when hanging in free space is to walk the rope. https://www.youtube.com/watch?v=gAzXYVdskFE https://www.youtube.com/watch?v=gAzXYVdskFE
  - module0000 8y ago
    Also, in those times when you need a prusik, there is a less-than-tiny chance you are hurt. EG: you're trying to place your cam, and instead you take a 40 foot drop before your last cam arrests your fall by sending your body directly into the face. Prusiks are more difficult to tie(and ascend!) when your hands are coated in your own blood, etc.
    - takk309 8y ago
      I have, thankfully, never had to try to tie a prusik with my hands covered in blood. If you had to do that, it sounds like a brutal fall.
    - planteen 8y ago
      Yeah for sure, injury changes things. You see rock climbers needing rescue often enough when they could have self-rescued by a pair of Prusiks and ascending the rope. I've heard of a rock climber using an ATC (rappel device) as an ascender, by kicking off the wall and moving the rope up a few inches. They were near complete exhaustion when they got up to the top - Prusiks would have made the job so much easier. Of course a pair of ascenders/Jumars is best, but add some weight. Most people (outside of cavers) don't plan on climbing up a rope with single rope technique, so it's not something that is practiced very much. I'm not really sure why. I'd be super nervous as a climber if I only could go one way on a rope. I guess alpinists practice it some for self-rescue out of a crevasse. Cavers use the rope as a nylon highway, so you know how to switch from rappel to climb, climb to rappel, and how to pick-off an injured party from the rope (all of those in space, where you can't take your weight off the rope at all).
Bartweiss 8y ago
It's always surprising to me how fall risks operate in the world of OSHA compared to rock climbing. There's an entire domain where people take good-sized falls as an everyday event, just sort of sitting in parallel with the domain where they're considered a major risk needing emergency-response measures. Obviously, some of that is a real difference in situation. Construction falls are unplanned and happen under all sorts of odd circumstances, and people are quite often injured during their falls. Climbers have someone managing the other end of their rope at all times, on a system that makes lowering them to the ground straightforward. But other differences seem absolutely pointless. The "suspended by your groin, legs hanging straight down" posture of construction harnesses massively accelerates suspension trauma, while climbing harnesses pull the legs up and keep pressure on large muscles. And there are companies starting to use that design for safety gear, so it's not a regulatory issue - it just somehow took decades to cross the gap.
- takk309 8y ago
  I big difference between a climbing harness and a construction harness is the tie in point. Climbing it is fine to have that point in front of the user. For construction, having the rope constantly in front of you would be a real inconvenience. By tying in on the back, the harness will hold the user in a different orientation just due to the way weight is distributed.
  - Bartweiss 8y ago
    That's definitely part of it; climbing harnesses tend to support you in a position that's great for suspension trauma, but involves a pretty inconvenient rope. They're also waist-and-hip only, and while they'll reliably hold a climber through a flip, it doesn't sound great for chaotic, confined-space falls where you might stay upside down. The newer generation of construction harnesses are still back-clipped and full-body though - a short strap runs from the waist to the back clip to redistribute weight without normally being in front of you. Presumably getting that working smoothly and safely was an extra engineering hurdle, but I'm still surprised harnesses went so long without even including waistbands.
- module0000 8y ago
burfog 8y ago
Falls from far less than that height can kill. If it is safe to be at 10 feet without that equipment, then it is safe to be at 1000 feet without that equipment. IMHO, the cutoff is just what the construction industry was willing to tolerate. The whole thing is a lobbyist battle between the construction industry and the safety equipment industry.
- newmac 8y ago
  I think that at a lower height, a rescue is considered to be easier. 10 ft would still require a safety program, it just wouldn't be fall arrest, more likely prevention (scaffolding)

yodon 8y ago

A similar root cause issue is developing life threatening blood clots from sitting too long. Both suspension trauma and blood clots in the legs come from a clever optimization of our circulatory system. The heart can't actually pump blood out of the legs. It counts on muscle activity to make the flow happen. If you sit for many hours, like on a cross country or cross ocean flight, or because you are a dev or gamer with tremendous concentration and focus, the blood quite literally just sits in your legs and eventually starts to coagulate. It doesn't matter how much exercise you get the rest of your day, those 6 or 8 hours of sitting can quite literally kill you through the creation of a blood clot that then flows through your system and blocks blood flow to the heart or brain (all learned personally when I developed such a clot from routinely sitting long hours in a coffee shop with my laptop and 100% focus). If you're like me and can focus easily for many hours straight, get a Fitbit, turn on activity tracking, and when it tells you you haven't walked around recently get up and walk around. It's much less impactful to your concentration than an emergency ER visit followed by a lifetime of prescription blood thinners to reduce the now much higher risk of a second clot.

tyingq 8y ago
"Deep Vein Thrombosis" is the term if anyone is looking for more info. https://www.cdc.gov/ncbddd/dvt/travel.html https://www.cdc.gov/ncbddd/dvt/travel.html
- mrkstu 8y ago
  Yep, flew from Phoenix to Atlanta, fell asleep until the end of the flight, woke to get off the flight, and immediately became blind in one eye as an embolism blew up inside the vitreous fluid. Not a great way to start a new job. Boss was meeting me at the airport thankfully and he drove me to the hospital to get checked out. A few weeks of an eye patch was the short term outcome and a bunch of new 'floaters' that my mind has mostly learned to filter out. Just very grateful that it detonated in my eye instead of my brain...
  - tyingq 8y ago
    The link I posted mentions it's not just air travel, but car, train, bus, etc, also. But I have to wonder if the shrinking coach seat pitch/size isn't a big factor. I'm fairly average size, but flying is miserable these days. Perhaps also the relative awkwardness of getting up while flying...the visible sighs from your row mates that have to move around a lot to let you pass.

leoc 8y ago

Yeah, interesting timing. It also seems quite similar to the effect of high (downward) G-forces.

hprotagonist 8y ago

Whenever i'm climbing outside i have a few lengths of dyneema or cordelette that i can rig into a prussick or kleinheist for self-rescue or for staying comfy at multipitch belays that don't have nice ledges. I don't hangdog all that much, so i was actually unaware of this risk, but it's worth keeping in mind!

oftenwrong 8y ago
Dyneema is not the best choice for friction hitches due to its low melting point. This is primarily a concern when using it as a backup for abseiling or lowering, or in any situation where you may take a fall onto the friction hitch.
- hprotagonist 8y ago
  I know. I don't use it for raps, but it's just fine as a static or static-ish anchor.
takk309 8y ago
This is less of a risk in a climbing harness due to the location of the tie in point. With the point in front of you at your waist, it is possible to shift your legs around even when free hanging. Think about doing a rappel on a long free hang. For me, I keep my legs in front of me and more or less above my waist. If you were tied in at a point on your back, as construction harnesses use, your center of mass is below the suspension point and the only position you can grab the rope is with your arms above and behind your head. Try doing a pull up in that positions, it is extremely hard.
- planteen 8y ago
  I once was indoors as a "training dummy" who got stuck on-rope rapelling and waited for someone to come up from the bottom to pick me off. My "tie in" point was a rack at my waist on the front. It takes a while to do this as it's not easy to climb past someone in single rope technique. I definitely felt my legs starting to go numb, even when I was kicking them around to keep blood flowing. I was hanging in space. That experience hit home to show the reality of harness hang syndrome.

QuotedForTruth 8y ago

Its interesting to me as a rock climber that I've never heard of this. Its not unusual for someone to hang in their harness at an anchor for quite a while while their partner is climbing the pitch before and after. Are climbing harnesses that much more comfortable than safety harnesses that its not a problem?

planteen 8y ago
It will still happen in a climbing harness if you are hanging in space. On a hanging belay, you try to get your weight off the harness and get your weight on your feet on the wall as much as possible. This alleviates the problem. Cavers will spend a long time hanging in space on rope when climbing out of deep pits (over 100 meters / 300 ft) with single rope technique. That doesn't lead to harness hang, because you are engaged in aerobic activity with your legs.
- QuotedForTruth 8y ago
  That is true. A free hanging belay would not be very useful! I did find some discussion on mountain project about it in the context of rescuing an incapacitated climber.
ska 8y ago
I think the lack of movement (especially if unconscious or barely conscious) and full suspension is key. When climbing, do you typically maintain contact with the wall, especially with you feet?
- QuotedForTruth 8y ago
  Barring injury, you wouldnt be hanging in free space for very long. I didn't realize that would make such a difference. After my comment I did some more searching and found plenty of discussion of harness hang syndrome in the context of rescuing an incapacitated climber though.
JshWright 8y ago
Are you typically hanging with all your weight in the harness, or are you leaning off the wall?

deleted 8y ago

[deleted]

amelius 8y ago

This is the stuff I think about when I find myself in an overly tight airline seat.

brandon272 8y ago
I am constantly and intentionally contracting my leg muscles when in an airplane. Mainly due to comfort issues, but I figure it is probably also helping blood flow.

reubenmorais 8y ago

Last time I went skydiving I experienced something like this. I was doing a pair jump and you do it in a harness that’s attached to the skydiver with the parachute. When the chute opens you slide down/into the harness and it compresses around your thighs. The first time I jumped, the instructor told me to step on his feet so he could put some slack in the harness, but this time the instructor didn’t do that, so for the whole time between opening the chute and landing I was stuck motionless in the tight harness. I almost passed out, it was pretty scary.

dangerboysteve 8y ago

This happens also to hunters that fall from hunting in tree stands and are wearing a safety harness.

quacked 8y ago

About a year ago, I was flying a hang glider and accidentally had a parachute deployment, and I ended up suspended in a tree, waiting for a grounds crew to come cut me down. The first thing that my friend said when I called him was "stand up if you can". Suspension trauma is a real risk for pilots who get stuck in trees, and it's a subject covered during parachute education clinics for that reason.

aasasd 8y ago

> as you inhale, the mediastinal intrapleural pressure becomes more negative, leading to expansion of the lungs, and pressure drops in the RA, RV, SVC, and IVC. Right Atrial expansion increases the pressure gradient for venous return So you're saying my lung volume has implications for the chance of deep vein thrombosis or possibly even for varicose veins? Great engineering right there.

BXLE_1-1-BitIs1 8y ago

A climber can reach the rope, put in a prussik and stand on it. No can do with construction harnesses. The rope's out of reach.

ken 8y ago
There are products available which enable one to self-rescue from a lanyard at your dorsal.

deleted 8y ago

[deleted]

grahamburger 8y ago

Interesting to see this pop up here! I'm in the process right now of getting my team Tower Safety Certified by Comtrain and this is one of the things they learn about. They also have to practice both being rescued from a tower (while hanging limp as though they were unconscious) and rescuing someone else from a tower. Gotta stay safe out there!

velosol 8y ago
Given the address in your profile I'd suggest you might also want to have your team have access to non-cell communications. Sometimes you're at a tower that doesn't have great cell reception and even if the team is able to rescue an injured member they won't be able to safely transport them and be stuck sending someone to find cell coverage and call for an ambulance.
- grahamburger 8y ago
  That's very true! Fortunately in our case (at least with the company I work for currently) we don't do any work outside of cell coverage or more than a few miles from a hospital. Part of the tower safety process though is to decide before climbing the tower where you will take someone if they get injured and how you'll get them them, or who/how you'll call if they can't be transported.

bitL 8y ago

Is this somehow related to feeling uneasy from skydiving once parachute is deployed as well? I sometimes feel like I am going to pass out. I had a scary situation while practicing multiple tailspins and free-falls on a sailplane and almost blacked out after the last one (basically couldn't feel anything and landed just by vision and mechanical yoke movements I couldn't feel at all.

DoctorMemory 8y ago

I started looking into a suspension system for Virtual Reality to increase immersion. I thought it was surprising that no one had made a harness type device. Then I came across suspension trauma and realized how complex an issue it would be to make something like that and take it public.

I_complete_me 8y ago

Coincidence or what? I attended a Safety Course (Construction) this very day and was introduced to the term orthostatic trauma which is also called suspension trauma. It so happens that I also do tree climbing with ropes and am familiar with prusik knots for ascension. Everyone should experience the sensation of climbing a single rope - it is magic. And finally I suffered bilateral pulmonory embolisms that I am putting down to excessive sitting while developing. My consultant told me that "20% don't make it to hospital"! Chilling memories. This article struck me thrice.

mindgam3 8y ago

Wow, I had no idea this was a thing. I nearly blacked out the first (and only) time I went skydiving. Tandem jump with instructor. Free fall was fun. After parachute deployed the harness started feeling tight around my chest and legs. I got dizzy and it felt like I was having a panic attack, difficulty getting enough oxygen. When we landed I immediately fell to the ground where I couldn’t get up for a few minutes. My friends who jumped with me were all laughing and having a great time, they thought I was being dramatic or something. A web search brought up tons of hits of this being discussed in skydiving forums. Apparently it’s related to older harnesses. Some skydivers don’t believe it’s real. Thanks for posting this.