Is PLF still relevant?

I've been thinking about this for a while, and have talked about it a bit with some people deeply involved with developing current training methods in the US, but thought I'd feel out here, if people think I'm off with this:

Clearly, learning to fall properly, when a landing does not go quite right, is an essential safety skill, and it has been my saving grace many times, especially on my first 100 jumps or so, but I feel like the current teachings around this topic may not quite be up to date with the reality of our sport. Like everyone else, I learned the good old PLF. And--I think also like everyone else--I tried to apply it in the real world, but if I am honest, in reality have practiced something that really wasn't quite what we learned.

Don't get me wrong: There are some crucial aspects of the PLF (such as rolling over the side and distributing the impact over as wide of an area of the body as possible, at the same time protecting the most vulnerable parts of the body) that absolutely apply now just as much as in the past, but: If you look at any depiction of the exact technique of the PLF, it becomes clear that the technique was designed for absorbing high vertical speed with almost negligible horizontal speed, and minimizing the impact on crucial body systems in such a scenario. This is of course exactly what one would have experienced during a landing with a round parachute at the time when this method was developed (and still now, as a paratrooper jumping similar systems)
However: This is generally NOT the situation during a (potentially) hard landing, using modern sports parachutes. In these situations, you are generally encountering fast horizontal speeds and varying vertical speeds, with a tremendous variety of exact scenarios. While again, something LIKE a PLF, or some principles of the PLF, still apply, I have noticed that many jumpers intuitively (or through experience) know that this does not work completely, and then design their own system (consciously or not) to deal with the reality of the situation. This can vary from from something like a rolling judo fall to "just slide it in"--and there is really no consistent system that gets trained that is fully applicable, since instructors and coaches simply have to train the "PLF", even though they would have to admit that they do not quite use it in the way it is described--if they were honest. (And clearly some solutions are better here than others.)

On the other hand, there are so many techniques from martial arts and especially parkour that may actually apply more here and could be trained if someone dared to update our current methods.

What do people with more experience think? Am I off about this? Can this "sacred cow" actually be updated? Does your own method of avoiding injury during (semi-) hard landings actually resemble the original PLF? Do you think it's good enough to continue teaching the PLF as a general system and trust that everyone will modify it to the actual situation they are in? If you think a PLF does not apply exactly as taught, what changes would you suggest?

Should this go under the safety forum? (I feel the forums, other than "Speakers Corner" are so underused these days that I am hoping to post this somewhere, where it's at least got a semi-decent chance of attracting some eyeballs and responses--but feel free to move it, moderators, if you think that's more appropriate)

I think the PLF is a good thing, for several reasons. Not sure what else could be used. Most of the Parkour type falls are simply modified PLFs, at least from what I've seen on the videos. 

First off, the forward speed one sees on landing usually isn't all that high (swooping excepted). If the landing is anything approaching normal, forward speed should be mostly bled off by the time the ground is met.

A more or less standard PLF is perfectly adequate for a fair amount of forward speed. You just roll forward more (further). I've turned running landings into PLF/forward rolls when I found that I couldn't move my legs fast enough to keep up with my body. 

Slides have their place, when properly executed. I've adopted/adapted something resembling a baseball style slide. I start it while the canopy is still supporting my weight, and just sort of settle down on the side of my leg and my hip as it progresses.
One problem with this is it needs smooth grass. If I'm not certain there aren't any holes or ruts, then I roll it out. I had one where I saw a nasty rut from the lawn mower tractor (probably 5" deep and at least 8" wide) that would have easily caught & injured my ankle. I abandoned the slide idea at the last second & rolled it out. 
Another problem is that it has to be done correctly. Tandems often slide in, landing straight on the butt. For a landing that is smooth & properly flared, this is ok. For anything else, it can cause spinal injuries. "Unteaching" students who want to do that can be challenging. 

5 hours ago, wolfriverjoe said:

"Unteaching" students who want to do that can be challenging. 

It gets worse when they are not students. I know a guy who injured his foot playing football at jump #60ish., and he decided to keep jumping but slide the next few landings in, so he would not put more stress on the injured foot. This was sometimes last year, the foot has healed, he has 200+ jumps and still slides in most landings. He has now started doing double front approaches, and is on his way to learning 90/270 accelerated approaches, and yet is still landing on his ass. 

13 hours ago, mbohu said:

I've been thinking about this for a while, and have talked about it a bit with some people deeply involved with developing current training methods in the US, but thought I'd feel out here, if people think I'm off with this:

Clearly, learning to fall properly, when a landing does not go quite right, is an essential safety skill, and it has been my saving grace many times, especially on my first 100 jumps or so, but I feel like the current teachings around this topic may not quite be up to date with the reality of our sport. Like everyone else, I learned the good old PLF. And--I think also like everyone else--I tried to apply it in the real world, but if I am honest, in reality have practiced something that really wasn't quite what we learned.

Don't get me wrong: There are some crucial aspects of the PLF (such as rolling over the side and distributing the impact over as wide of an area of the body as possible, at the same time protecting the most vulnerable parts of the body) that absolutely apply now just as much as in the past, but: If you look at any depiction of the exact technique of the PLF, it becomes clear that the technique was designed for absorbing high vertical speed with almost negligible horizontal speed, and minimizing the impact on crucial body systems in such a scenario. This is of course exactly what one would have experienced during a landing with a round parachute at the time when this method was developed (and still now, as a paratrooper jumping similar systems)
However: This is generally NOT the situation during a (potentially) hard landing, using modern sports parachutes. In these situations, you are generally encountering fast horizontal speeds and varying vertical speeds, with a tremendous variety of exact scenarios. While again, something LIKE a PLF, or some principles of the PLF, still apply, I have noticed that many jumpers intuitively (or through experience) know that this does not work completely, and then design their own system (consciously or not) to deal with the reality of the situation. This can vary from from something like a rolling judo fall to "just slide it in"--and there is really no consistent system that gets trained that is fully applicable, since instructors and coaches simply have to train the "PLF", even though they would have to admit that they do not quite use it in the way it is described--if they were honest. (And clearly some solutions are better here than others.)

On the other hand, there are so many techniques from martial arts and especially parkour that may actually apply more here and could be trained if someone dared to update our current methods.

 

What do people with more experience think? Am I off about this? Can this "sacred cow" actually be updated? Does your own method of avoiding injury during (semi-) hard landings actually resemble the original PLF? Do you think it's good enough to continue teaching the PLF as a general system and trust that everyone will modify it to the actual situation they are in? If you think a PLF does not apply exactly as taught, what changes would you suggest?

 

Should this go under the safety forum? (I feel the forums, other than "Speakers Corner" are so underused these days that I am hoping to post this somewhere, where it's at least got a semi-decent chance of attracting some eyeballs and responses--but feel free to move it, moderators, if you think that's more appropriate)

did you read the article i wrote on the plf?  it is very much still appropriate, and i have used it many times to prevent injuries in other areas besides parachute landings.  i would think that if anything, we don't teach it well enough.  it takes a week of landings during jump school while we make the new jumper do it what, five times max, and from a bench at that.  jump school teaches it on the platform, then the zip line, then the sling load trainer (the really fun one).  if anything, i would increase the time spent on plfs to at least an hour, and have the student jumpers do five before every jump, not modify it at all. 

regardless of the amount of forward speed(up to about 25 mph anyway), it is safer to absorb the impact with every joint that will bend and roll as much as necessary to bleed off the speed.  i had to take a downwind landing to avoid powerlines and had about 20 mph forward speed into a plowed field that was dry as a bone once, rolled twice and ended up with a few scrapes.  even when done wrong, they can help avoid injury as long as you keep your feet and knees together and bend everything and roll it out.  you can't say that for sliding in, or any other landing type that i know of.  improving our methodology is always a good thing, but if it ain't broke, don't fix it.  change for change's sake is never a good thing.  when you come up with a better landing technique that works well when done wrong, test it well and see what happens, also, let me know so i can try it out myself.  i am always up for improving things, but some things just can't be improved on.  that doesn't mean we should stop trying.

I learnt on rounds so a PLF is natural for me.  If I'm coming in fast I will just continue the roll as much as is needed.  I have never hurt myself on landing.  My concern with students today is will they ever get enough practise to do it instinctively.

The idea of sliding-in a landing that you know is going to go bad, seems absolutely crazy to me.  If it is going wrong just do a PLF and protect yourself in both the vertical and horizontal axis.

PLF still makes sense at the novice level, and that's the level that is normally taught in skydiving for nearly everything. At a more advanced level, that's where in skydiving we have generally had to learn much more on our own. And people now are taking more and more canopy control classes, whether enforced at the intermediate level (depending on jurisdiction), or for learning swooping a little further down the road.

I don't know what other coaches have done, but when I've taught canopy classes for those just getting into faster canopies, all those other variations on landing do come up: All the stuff about how if you aren't going to run out a landing, you can slide, but there are all sorts of things to be aware of relating to protecting the spine, foot position, roughness of the ground, and so on.

I can't recall exactly what they do in judo or parkour, but I think one sees rolls that are a little more of a 'forward roll', although still twisted to the side.  That might work if one is flexible with no gear on, and with certain softer surfaces and with certain moderate speeds. Worth looking at but I doubt anything is going to greatly change skydiving landing rolls.

As an example of a situation where both sliding and PLF can work together: A low slide, one butt cheek on the ground, can be good for scrubbing off speed if the ground is smooth. But if you might hit an obstacle, say a rock, dirt ridge, or stump in some higher grass, then it would be better to slide with the feet but keeping one's torso off the ground, and the center of gravity higher, so that if one hits something, one can at least get thrown forward into some sort of roll, instead of piling straight into the obstacle.

PLF is still great for vertical speed, sliding is great for horizontal speed if the surface is smooth, and for everything in between, it gets a little more complicated, but the PLF is still the first thing you want to have in your toolbag.

 I think this PLF topic falls less into the category of "what's wrong with the PLF", than "how do we keep educating skydivers on more advanced knowledge, after they are licensed and are no longer students". 

my one attempt to plf back in the student days circa 2003 did not go well. I was on a 288 manta, probably 3rd jump, and was told if your radio doesn't work, half-brake landing and plf.

my radio didn't work.

I landed way out and dutifully got on to final with my hands at ear level, feet and knees together and flexed and waited to hit the ground. and did i. somehow i bounced flipped up and landed on my neck / head.  

i wish there was video, as to this day i don't know how that happened. but my plf training was completely inadequate for a half-brake landing on light wind day, even on a big manta.  

Quote

While again, something LIKE a PLF, or some principles of the PLF, still apply, I have noticed that many jumpers intuitively (or through experience) know that this does not work completely, and then design their own system (consciously or not) to deal with the reality of the situation.

To my recollection, proper PLF involves feet together, knees together and roll TO THE SIDE on first contact. Modern parachutes have forward speed that makes this impossible.

So one either has to turn body 90 degrees sideways right before touchdown and roll to the side (= along the forward speed of the parachute)

Or roll forward on touchdown.

Or combination of both.

All are modified PLF, I agree with the author.

Nobody questions usefulness of that type of landing. It's just that instructions on how to perform it have gaps and holes and don't make that much sense. For me the biggest take away is FEET AND KNEES TOGETHER and then roll part is improvised. I wish there were better instructions out there.

5 hours ago, wmw999 said:

I PLF more than most people. In fact, my default landing is  PLF, with a standup being a last-minute decision if everything looks perfect. And it's a fairly honest PLF, generally done only when it's a no-wind or downwind landing, so there is some speed.

Wendy + others: Are you sure though that what you do is a PLF as it is taught? The way I have seen it taught and the way it is depicted everywhere really works best with zero forward speed or even some backing up: feet completely together and then start the roll over the side and then the back: 

In my experience: keeping your feet rigidly together on a downwind landing (or even a fast cross-wind or no-wind) is not always the best strategy--particularly, if you say you start running out and then go into a PLF, I bet you are doing something similar to what I do, which resembles a judo-roll more. The roll is also executed more over the side in the forward direction and while turning towards your back is helpful, it doesn't look exactly like depicted. Lastly, I definitely engage my arms differently to help to direct the force of the roll (obviously not to break the fall, which would create the danger of broken arms, but pulling the arm on the side I roll over in, towards the body, helping to make it a more rolling movement and protecting parts of the body at the same time.) So I'm not saying: don't teach the right way to fall, but: teach it more realistically. And yes, that is harder, because you can't easily simulate the forward speed on the ground.

  I agree that saying "slide it in" is not a good option, because "sliding it in" really requires you to continue to fly the parachute, to make it safe and successful, and a PLF is for when you've somewhat given up on that part...or at least you don't want students to depend on that skill, which they probably aren't good at yet.

Maybe it's not that important and people do fine learning the regular PLF and then just use it in a modified way--but I have definitely noticed that what I see being practiced does not match with the original version of a PLF.

15 minutes ago, CoolBeans said:

Nobody questions usefulness of that type of landing. It's just that instructions on how to perform it have gaps and holes and don't make that much sense. For me the biggest take away is FEET AND KNEES TOGETHER and then roll part is improvised. I wish there were better instructions out there.

Yes, thank you. That's what I meant.

Not sure if this has been said or not, but a couple of concepts:

1. You have 100 jumps.  Pretty early to be questioning foundational techniques of the sport and dictating your understanding of emergencies to a much more experienced audience.

2. From personal experience, PLF works great.

Personal experience:
* Many friends with lumbar fractures from "trying to slide it in"

* Friends that PLF don't get injured nearly as much

In about 600 jumps I have had to PLF about 3 times, but I'm glad those 3 times that was the intuition that was drilled into me - because I would have broken myself otherwise.

If you have a landing emergency more than once every hundred to two hundred jumps, take a hard look back at what you are doing wrong.  Maybe get canopy coaching?  Stop jumping in shit winds?

On an even more personal note, on the same jump, landing at the same time, my wife and I were landing in the same shit conditions a few feet from each other.  I PLF'd and walked away with some bruises.  She didn't jump for the rest of the season.

PLF.  It's better than the alternative.

4 hours ago, sfzombie13 said:

if anything, i would increase the time spent on plfs to at least an hour, and have the student jumpers do five before every jump, not modify it at all. 

Yes, I absolutely agree with teaching it more and longer. But again, I would then also teach it more the way it actually is executed. If you look at the picture above, the only time I've seen it executed in a similar fashion is when a student flares much too high, runs out of forward speed and then drops straight down.

4 minutes ago, lyosha said:

1. You have 100 jumps.  Pretty early to be questioning foundational techniques of the sport and dictating your understanding of emergencies to a much more experienced audience.

I thought I updated my jump numbers, but maybe not--I'll check. I have about 480 jumps and a coach license. I had the privilege of spending some longer time with Jen Sharp recently, seeing her thoughts on teaching and USPA methods (disclaimer: none of what I'm saying here comes from her, so don't blame her for it!...but it made me think more about some topics around teaching)

AGAIN: Let me clarify here: I am absolutely not for teaching "sliding it in". This comment was meant to illustrate the problems with not teaching the PLF in a way that applies for our types of landings. It comes from this encounter:

I talked to an instructor examiner and said something similar, that I feel like the PLF as taught doesn't really work completely in real world landings and if he wouldn't think that maybe it could be taught differently, and the instructor examiner answered: "yeah, well, we just slide it in, right?" (not sarcastically!) So I thought that is a bit of an issue: When people feel that a method doesn't quite apply as it is taught, they either modify it themselves (more or less successfully) or they abandon it completely (the "slide it in" crowd). Wouldn't it be better to teach a version of a landing fall that applies more closely, so can be used without too many modifications, so we don't rely on the student's ability to modify it appropriately? That's where I'm coming from.

23 minutes ago, lyosha said:

If you have a landing emergency more than once every hundred to two hundred jumps, take a hard look back at what you are doing wrong.

Again, I am writing this from the perspective of seeing it in coaching students and AFF students.

Although I've certainly had some landings where I had to roll it out. (what most people would call a PLF--but really it wasn't.)

Of course, when I talk to students I teach the PLF and I suggest to PLF, whenever in doubt--but if they inquire a bit more deeply I do tell them how I actually execute it in most scenarios, and that looks a little different than the "keep your feet together and roll over the side to the back" method that is so perfect for zero forward speed.

Also: I mostly jump in Colorado and often at a DZ where cross-wind landings into pretty good winds at 5,000+ feet elevation are more the standard than the exception. So you get to see a lot of "PLF"s here--and it makes you think about how to make them better, especially when you see people getting hurt.

1 minute ago, mbohu said:

Yes, I absolutely agree with teaching it more and longer. But again, I would then also teach it more the way it actually is executed. If you look at the picture above, the only time I've seen it executed in a similar fashion is when a student flares much too high, runs out of forward speed and then drops straight down.

there are four directions in a plf, front, both sides, and back.  whether you go forward or backward depends on the direction of travel, mostly forward with square canopies.  it took me a week to learn how to plf, but i was with about 500 other folks and we had nothing but time.  i could teach you how to do it in an hour, maybe a little more, but you would never get the same thing from it that i got.  if you set up a zip line and a platform, you can simulate a plf accurately and would see how it does work with forward motion.  i don't know how many movies you've watched, but round parachutes rarely fall straight down.  mostly they move, forwards if you're lucky, but they move and pretty fast sometimes. 

when you are going in for a landing, you flare, then if you can't just set your feet down (they should already be together), you simply face to the right or left slightly and roll it out.  that is a proper plf.  if you're going fast, you may roll twice.  you may have a step through.  but you'll be fine, with no broken bones.

3 hours ago, mbohu said:

Wendy + others: Are you sure though that what you do is a PLF as it is taught? The way I have seen it taught and the way it is depicted everywhere really works best with zero forward speed or even some backing up: feet completely together and then start the roll over the side and then the back:

I noticed that the USPA SIM does have a detailed description of a PLF. It isn't perfect, but at least does put a lot of detail into the roll.
It doesn't however get into differences between low and high horizontal speed for example. It just mentions leaning into the direction of the landing (whatever direction that may be - not necessarily forward or straight down). So the legs would always be slightly 'back' of vertical, with no rules about how to deal with cases with more speed -- where people might have legs out in 'front'.

E.g. -  if one is going forward, and about to hit at a 45 degree angle from the vertical, then:

a) the classic PLF instructions would have you trail legs slightly BEHIND you. Giving you very little support going into the PLF! -- You would pretty much catch the feet on the ground and then body slam the ground. 

Ok, that's exaggerating somewhat. Classic PLF may still work as that angle is similar to round canopy jumps with a lot of wind. But as the horizontal speed increases and the angle of arrival is closer towards the horizon, this situation (a) becomes more true.

b) But it would also be bad to have legs out 45 degrees in front relative to your center of mass, as that would pile drive you into the ground when moving at that 45 degree descent. Impact point with feet are directly in line with your motion and center of mass. 

c) So you would want legs out in front a little, to absorb some impact and slow down a bit, but with the center of mass then going 'over' your legs to enter a roll. 

d) It would be overdoing things to have legs up higher than 45 degrees from center of mass, as that would tend to make you slide but also pitch butt down, and smack pelvis & spine into the ground.

So on the one hand the SIM does go into more detail than the 'classic 1960s round canopy' sort of diagram (that you show), but it doesn't get into all the modern issues (that you were concerned about when starting the thread).

This kind of stuff is good for making one's own thoughts on a subject clearer and better organized!

My sketch could be clearer but shows a few of the points above:

1 hour ago, pchapman said:

I noticed that the USPA SIM does have a detailed description of a PLF. It isn't perfect, but at least does put a lot of detail into the roll.
It doesn't however get into differences between low and high horizontal speed for example. It just mentions leaning into the direction of the landing (whatever direction that may be - not necessarily forward or straight down). So the legs would always be slightly 'back' of vertical, with no rules about how to deal with cases with more speed -- where people might have legs out in 'front'.

E.g. -  if one is going forward, and about to hit at a 45 degree angle from the vertical, then:

a) the classic PLF instructions would have you trail legs slightly BEHIND you. Giving you very little support going into the PLF! -- You would pretty much catch the feet on the ground and then body slam the ground. 

Ok, that's exaggerating somewhat. Classic PLF may still work as that angle is similar to round canopy jumps with a lot of wind. But as the horizontal speed increases and the angle of arrival is closer towards the horizon, this situation (a) becomes more true.

b) But it would also be bad to have legs out 45 degrees in front relative to your center of mass, as that would pile drive you into the ground when moving at that 45 degree descent. Impact point with feet are directly in line with your motion and center of mass. 

c) So you would want legs out in front a little, to absorb some impact and slow down a bit, but with the center of mass then going 'over' your legs to enter a roll. 

d) It would be overdoing things to have legs up higher than 45 degrees from center of mass, as that would tend to make you slide but also pitch butt down, and smack pelvis & spine into the ground.

So on the one hand the SIM does go into more detail than the 'classic 1960s round canopy' sort of diagram (that you show), but it doesn't get into all the modern issues (that you were concerned about when starting the thread).

This kind of stuff is good for making one's own thoughts on a subject clearer and better organized!

My sketch could be clearer but shows a few of the points above:

you are way over thinking this plf thing.  there is no classic plf, or any other type than the one.  the legs are underneath you always, never in front or behind.  the only thing you need to really do is keep your feet and knees together, bend at every joint that can bend, and roll it out.  that is the plf in a nutshell.  it takes way more practice to do it and keep your feet and knees together.  they had to tie my boots together and i hopped around all day long at jump school.  it worked though.  students should spend at least an hour on it all by itself, and they should also do at least five before every jump.  on the radio, the person talking the jumper down should say, "prepare to land, hands up, feet and knees together to prepare for a plf, flare" right before landing, but like wendy, i am also not an instructor nor in charge of anything. 

6 hours ago, sfzombie13 said:

The only thing you need to really do is keep your feet and knees together, bend at every joint that can bend, and roll it out.  that is the plf in a nutshell.

This is the essence of the PLF.

Don’t take this as a personal shot at you, this is about me and a lot of us. I too thought that some things should be changed in training when I had a few hundred jumps and started working with students. It took another few hundred jumps and working with a bunch of students to figure out how much I really knew. This was before the ISP, when training was different at every different drop zone. You, like me back then, are not totally wrong. What you need to remember is that PLF’s are taught in the FJC. The whole purpose of the FJC, and even the entire student progression in the ISP, is not to teach the student to be a great skydiver. It is to give them a base to build on. 
The PLF is a relatively simple multi purpose technique. It is a basic method to minimize injury. I would no more expect this to be the only technique for someone with a couple hundred jumps to deal with a downwind landing than I would expect then to use a single stage flare.

USPA has come a long way over the last 20 years with the ISP, both in it’s original form and what it has evolved into. There have been changes and there will be more. The current and former directors of Safety and Training have moved thing ever forward. The current Chair of the Safety and Training committee, along with the committee members are constantly modifying the program, making changes when they make sense, but not trying to reinvent what works.

Bottom line, you’re right that there are a lot of variations on the PLF that, in certain circumstances work better than the exact version taught to students. But the basic PLF is what the student needs and should be taught. My concern is that in this age of modern parachutes it isn’t taught and practiced enough. 

13 hours ago, mbohu said:

Wendy + others: Are you sure though that what you do is a PLF as it is taught? The way I have seen it taught and the way it is depicted everywhere really works best with zero forward speed or even some backing up: feet completely together and then start the roll over the side and then the back: 

It's "feet together and angled slightly to the side" (translation difficulties). Also, you obviously must flare before you touchdown, keeping your hands together near your crotch, your elbows tucked in etc.

That way you are able to make the roll in the flying direction. Based on the quoted picture you would face plant, hard.

All in all that has nothing to do with the PLF in general and everything with the quality of the picture.

I've had a student once who during FJC insisted that sliding it in was better than PLF. I made him stand on a table and asked him whether he'd like to land on his ass. When he said no, I asked him why it would be a good idea to do so when jumping from 1 km instead of from a table.
A second student didn't discuss but just landed on his ass a few times. He'd get a talking to, promised to do better but was stubborn. After a few jumps he had to be taken to the hospital with a fractured tailbone.

Personally, the PLF allowed me to jump earlier after recovering from a knee injury. No problem at all rolling the entire season.

The PLF is one of the most important safety skills to learn. It's saved my butt numerous times. Even if you develop a sliding-in or similar technique to dissipate forward movement, you still want the PLF in your tool box. You could get sink on landing, turbulence could collapse your canopy, you might land off and have to land in a tight spot in deep brakes, you could have an entanglement and land under two (or 1) malfunctioning canopies, heaps of stuff could happen where a PLF may make the difference between walking away dirty and sore or going to the hospital.