Do you have specific advice for posture and anatomy as it relates to trim?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Ryan Neely

Contributor
Messages
217
Reaction score
117
Location
Akeley, MN USA
# of dives
200 - 499
My buddy (wife) and I have been diving at least once a week (and sometimes twice) since obtaining our Open Water cert. at the end of May. It's been just over a month and we have logged almost ten hours underwater. Our primary goal this year is to practice, practice, practice. Of course, the first area we're focusing on is buoyancy.

What's interesting is that, when we're not thinking about it (i.e., filming each other for later review or inspecting a school of bluegills), we seem to be capable of maintaining neutral buoyancy fairly well. Of course, we're only diving in thirty feet of water at most, so "fairly neutral" is really giving me a latitude of twelve to eighteen inches in either direction.

Anyway, I'm digressing. The point of this post has to do with a question I have regarding proper trim.

So, I understand that proper trim is really a part of obtaining proper buoyancy. I also understand that "ideal"* trim (for a diver in a wetsuit) is for your arms to be straight out in front of you (like you're Superman flying through the air), your torso and thighs to be horizontal, your head to be up (so you can see forward), your knees bent so your calves are at 90° to the rest of your body, and your feet flexed so your fins are parallel to your body.

Basically, the same position you'd be in if you were skydiving (prior to opening your parachute).

Here's where my concern lies. Each time I put myself into this position in the water my body seems to rotate on its own along the x-axis of my hips. Basically, imagine a body in the aforementioned skydiving position and then imagine that body slowly rotating so the head is pointed straight up at the surface, the knees are pointed straight down at the bottom, but nothing else has change. The knees are still bent, the calves are still 90° to the thighs and torso, the feet are still flexed, the arms are still stretched out in a Superman pose.

So, I kick my fins in a modified version of a helicopter kick to reposition myself horizontally, settle, and wait for the whole process to repeat itself.

A couple of thoughts I've had right off the bat:

1.) I have had a terrible time with anterior pelvic tilt. I've seen a physical therapist about it and have been correcting this problem, but it has prevented me from doing a lot of things (though, positioning myself in a skydiving pose shouldn't be one of them; anterior pelvic tilt is exactly that position).

2.) Thanks to the anterior pelvic tilt, my lower abdominals, glutes, hamstrings, and aductors aren't as strong as they probably could or should be. Due to this weakness, it is possible I'm not "clenching" or "holding" as long or as well as perhaps I should. It's like a kid trying to keep his arm raised to answer a question in school but he's just not strong enough for that kind of isometric hold (so he has to hold up his raised arm with his other arm).

3.) It is also possible that my weights are not positioned properly around my body. It seems like 18 lbs. is just about the right weighting for me (based on a PADI weight check) in my 5mm suit. I've got six pounds in each of my weight pouches on my BCD and 3 pounds in each of my trim pockets (though, to be honest, the trim pouches aren't that much higher overall on my torso than the weight pouches). I've also adjusted my tank to ride higher than I was trained (basically if I tilt my head to look forward, my first stage presses into the back of my skull; not painfully, but I'm aware of its presence).

Could my weight distribution be counter-intuitive, like the way a bicycle saddle's angle is counter-intuitive in terms of pinching the nerves in your groin?**

Any advice you have is welcome. Thanks in advance!

*Note: I put ideal in quotes here because I realize that there are many different ideas and many different options depending on body type, diving style, and preference. Talking ideal trim is probably like asking whether or not I should buy split fins.

**Note: It seems that if you're having nerve pain in your groin due to your bike seat, the intuitive response would be to lower the nose of the seat to alleviate pressure built up there. However, the actual way to alleviate that pressure is to tilt the nose up slightly. This seems counter-intuitive, but it works thanks to the anatomy of how we sit on bicycle seats.
 
The "correct" trim is the correct trim for the circumstance. You don't always have to be perfectly horizontal, however generally it's the most efficient for swimming forwards and the position you'll see skilled divers diving in a lot of the time.

As to your description of trim, I don't like the "superman" analogy. That would indicate that your arms are straight out, they should be pretty relaxed - when you are in trim you'll find they'll naturally be in position. Some divers hold-hands and it's not a bad technique to start with as it gives a good approximation of the position. Check out the pics below.

https://portofinodivers.com/files/img/content_box/fund_content_box.jpg

https://image.shutterstock.com/z/st...n-diver-with-underwater-camera-1338744134.jpg


As for the rolling - that's not at all an uncommon thing for people when they first start. A lot of people roll sideways, but it sounds like you are finding your hips sinking and your head rising?

I'd start by getting into what you think is the correct position, then clenching your glutes as hard as you can. That should ensure that your legs aren't dropping. Can you then get your dive buddy to take a photo or video? Because often when people think their body is doing is not what it's doing.

Secondly, once you are sure you are actually starting in the right position, i'd look at your weighting. Often new divers have far too much weight, and stick it all around the hips. That means you have a big gas bubble in your BCD which is trying to lift you up while the weight belt drags your hips down.

So - start by doing a proper weight check. You should only have enough to be able to hold your 10ft stop with an empty tank. Then you can look to shift the weight around a little as needed.

What are you diving in? What kind of BC / wetsuit etc?
 
Word @Griffo. I've got a GoPro just for this specific purpose. I figured we'd want to film each other as we practiced certain skills and techniques. (It's better to see yourself later and have a visual for what something felt like over taking someone else's word for it.)

I'll try the glute squeeze ... and relaxing my arms.

The photo in your link is almost exactly how I start out. I'll try to get a video of the "rolling" I'm noticing. Maybe it's something different.

Thanks for the tips!
 
I like your approach and desire to get it just right.

Definitely play with the location of your weights. This can take quite a few dives to get spot on. It's good practice to just hang there and observe any rotation to make a mental note or even adjust it under water if you and your wife are comfortable with this.

With your high tank, are you able to turn the first stage upside down (switch all hoses around) to have less of the stage protrude upwards? If I have my MK17 the normal way up, I would hit my stage, once I turned it upside down, I am clear.

I can't get around saying that a bp/w system would go a long way towards what you are after. I found that it by default placed me really well (aha! moment) with the bulk of weight ideally positioned in the backplate and STA, and the rest was just a bit of tinkering with tank height and waist strap and cam band mounted weight pouches.

Body position wise, for rec diving, as long as your belly is approximately the lowest point, feel free to do what's comfortable with your arms. Frog kick by default if you don't already, and the resting position of your fins will be just fine.
 
Assuming you have the pose correct, you are just a seesaw in the water. Absent some dynamic fine tuning via lower leg angle and skulling.

If your hips swing down, move more of your weight higher. If you have lead to play with, its nothing more involved than school yard seesaw physics. Holding a 1lb. weight in each hand allows you to shift that much weight up and down your body to see where you naturally stay level. Obviously don't dive normally with lead in hand. Use it as an exercise to see how much you need to move, and to where.

For handiness in diving, it helps to have extra room in your hip weight pockets, or perhaps shoulder trim pockets to stow them after playing with them. The DGX trim pockets are small yet handle a few pounds easily. At $10/ea, one on each shoulder is a handy way to play with weight distribution.

If your 'trim' pockets are worthless for trim, get some higher up. You need more options than hips or hips+3".

+1 on BP/W

I've no connection to UTD, but their video shows this playing with trim location fairly well, just not with a full kit on. They may not always be level, but holding lead and moving it head/tail to see is the idea.
 
I think you are over thinking trim. You can tie a boltsnap or double ender to a couple of small 2-4lbs weights as part of your 18lbs then you can play with moving then around to get the proper trim balance. You can have your buddy or wife move the weights until your balanced while you do your best sky diver statue impression sometimes that is quicker to have an external eye do the balancing.

One you know where you need the trim weights you just need to keep that balance on all your dives.
 
Here's where my concern lies. Each time I put myself into this position in the water my body seems to rotate on its own along the x-axis of my hips. Basically, imagine a body in the aforementioned skydiving position and then imagine that body slowly rotating so the head is pointed straight up at the surface, the knees are pointed straight down at the bottom, but nothing else has change. The knees are still bent, the calves are still 90° to the thighs and torso, the feet are still flexed, the arms are still stretched out in a Superman pose.
.


Sounds like you have a weight distribution problem.

Are you diving a Jacket style BCD? in that case all of the weight is concentrated on your weight belt / pockets which is placed on your hips.
This will of course make your lower body "sink" down and instead of the flat angle you will get more of a tilt.

If you are using a BP/W you should consider getting trim pockets and spreading the weight through out your rig.
In your case, try shifting some weight to the upper body (trim pockets on tank bands for example).

Also 18 pound seems a little excessive,Im a fairly big guy and with my 5mm i use 12-14 pounds max on AL80.
You should consider having a pool / shallow water session and try removing some weight, being over weighted can also cause trim problems.
 
My buddy (wife) and I have been diving at least once a week (and sometimes twice) since obtaining our Open Water cert. at the end of May. It's been just over a month and we have logged almost ten hours underwater. Our primary goal this year is to practice, practice, practice. Of course, the first area we're focusing on is buoyancy.

What's interesting is that, when we're not thinking about it (i.e., filming each other for later review or inspecting a school of bluegills), we seem to be capable of maintaining neutral buoyancy fairly well. Of course, we're only diving in thirty feet of water at most, so "fairly neutral" is really giving me a latitude of twelve to eighteen inches in either direction.

Anyway, I'm digressing. The point of this post has to do with a question I have regarding proper trim.

So, I understand that proper trim is really a part of obtaining proper buoyancy. I also understand that "ideal"* trim (for a diver in a wetsuit) is for your arms to be straight out in front of you (like you're Superman flying through the air), your torso and thighs to be horizontal, your head to be up (so you can see forward), your knees bent so your calves are at 90° to the rest of your body, and your feet flexed so your fins are parallel to your body.

Basically, the same position you'd be in if you were skydiving (prior to opening your parachute).

Here's where my concern lies. Each time I put myself into this position in the water my body seems to rotate on its own along the x-axis of my hips. Basically, imagine a body in the aforementioned skydiving position and then imagine that body slowly rotating so the head is pointed straight up at the surface, the knees are pointed straight down at the bottom, but nothing else has change. The knees are still bent, the calves are still 90° to the thighs and torso, the feet are still flexed, the arms are still stretched out in a Superman pose.

So, I kick my fins in a modified version of a helicopter kick to reposition myself horizontally, settle, and wait for the whole process to repeat itself.

A couple of thoughts I've had right off the bat:

1.) I have had a terrible time with anterior pelvic tilt. I've seen a physical therapist about it and have been correcting this problem, but it has prevented me from doing a lot of things (though, positioning myself in a skydiving pose shouldn't be one of them; anterior pelvic tilt is exactly that position).

2.) Thanks to the anterior pelvic tilt, my lower abdominals, glutes, hamstrings, and aductors aren't as strong as they probably could or should be. Due to this weakness, it is possible I'm not "clenching" or "holding" as long or as well as perhaps I should. It's like a kid trying to keep his arm raised to answer a question in school but he's just not strong enough for that kind of isometric hold (so he has to hold up his raised arm with his other arm).

3.) It is also possible that my weights are not positioned properly around my body. It seems like 18 lbs. is just about the right weighting for me (based on a PADI weight check) in my 5mm suit. I've got six pounds in each of my weight pouches on my BCD and 3 pounds in each of my trim pockets (though, to be honest, the trim pouches aren't that much higher overall on my torso than the weight pouches). I've also adjusted my tank to ride higher than I was trained (basically if I tilt my head to look forward, my first stage presses into the back of my skull; not painfully, but I'm aware of its presence).

Could my weight distribution be counter-intuitive, like the way a bicycle saddle's angle is counter-intuitive in terms of pinching the nerves in your groin?**

Any advice you have is welcome. Thanks in advance!

*Note: I put ideal in quotes here because I realize that there are many different ideas and many different options depending on body type, diving style, and preference. Talking ideal trim is probably like asking whether or not I should buy split fins.

**Note: It seems that if you're having nerve pain in your groin due to your bike seat, the intuitive response would be to lower the nose of the seat to alleviate pressure built up there. However, the actual way to alleviate that pressure is to tilt the nose up slightly. This seems counter-intuitive, but it works thanks to the anatomy of how we sit on bicycle seats.
Could you repeat that?
 
Nice post, I like where your (and your wife's) head is as far as improving and striving for more/better.

First, don't worry too much about hands out forwards from your body. Just whatever is comfortable for you. I generally have my fingers interlocked just below my sternum, because that's comfortable for me.

Secondly, as a couple others have asked, are you diving Jacket or Backplate?

Either way, you can try setting your tank forwards(higher/towards your head) a bit to shift some weight without actually moving any weights.

Besides those, what is your wetsuit thickness and what fins? It may be possible to lose some "weight" at your feet to help balance out. (i.e. more buoyant fins or thicker booties, or both...)

At any rate, keep working on it and you'll get there! Don't get discouraged :thumb:
 
My buddy (wife) and I have been diving at least once a week (and sometimes twice) since obtaining our Open Water cert. at the end of May. It's been just over a month and we have logged almost ten hours underwater. Our primary goal this year is to practice, practice, practice. Of course, the first area we're focusing on is buoyancy.

What's interesting is that, when we're not thinking about it (i.e., filming each other for later review or inspecting a school of bluegills), we seem to be capable of maintaining neutral buoyancy fairly well. Of course, we're only diving in thirty feet of water at most, so "fairly neutral" is really giving me a latitude of twelve to eighteen inches in either direction.

Anyway, I'm digressing. The point of this post has to do with a question I have regarding proper trim.

So, I understand that proper trim is really a part of obtaining proper buoyancy. I also understand that "ideal"* trim (for a diver in a wetsuit) is for your arms to be straight out in front of you (like you're Superman flying through the air), your torso and thighs to be horizontal, your head to be up (so you can see forward), your knees bent so your calves are at 90° to the rest of your body, and your feet flexed so your fins are parallel to your body.

Basically, the same position you'd be in if you were skydiving (prior to opening your parachute).

Here's where my concern lies. Each time I put myself into this position in the water my body seems to rotate on its own along the x-axis of my hips. Basically, imagine a body in the aforementioned skydiving position and then imagine that body slowly rotating so the head is pointed straight up at the surface, the knees are pointed straight down at the bottom, but nothing else has change. The knees are still bent, the calves are still 90° to the thighs and torso, the feet are still flexed, the arms are still stretched out in a Superman pose.

So, I kick my fins in a modified version of a helicopter kick to reposition myself horizontally, settle, and wait for the whole process to repeat itself.

A couple of thoughts I've had right off the bat:

1.) I have had a terrible time with anterior pelvic tilt. I've seen a physical therapist about it and have been correcting this problem, but it has prevented me from doing a lot of things (though, positioning myself in a skydiving pose shouldn't be one of them; anterior pelvic tilt is exactly that position).

2.) Thanks to the anterior pelvic tilt, my lower abdominals, glutes, hamstrings, and aductors aren't as strong as they probably could or should be. Due to this weakness, it is possible I'm not "clenching" or "holding" as long or as well as perhaps I should. It's like a kid trying to keep his arm raised to answer a question in school but he's just not strong enough for that kind of isometric hold (so he has to hold up his raised arm with his other arm).

3.) It is also possible that my weights are not positioned properly around my body. It seems like 18 lbs. is just about the right weighting for me (based on a PADI weight check) in my 5mm suit. I've got six pounds in each of my weight pouches on my BCD and 3 pounds in each of my trim pockets (though, to be honest, the trim pouches aren't that much higher overall on my torso than the weight pouches). I've also adjusted my tank to ride higher than I was trained (basically if I tilt my head to look forward, my first stage presses into the back of my skull; not painfully, but I'm aware of its presence).

Could my weight distribution be counter-intuitive, like the way a bicycle saddle's angle is counter-intuitive in terms of pinching the nerves in your groin?**

Any advice you have is welcome. Thanks in advance!

*Note: I put ideal in quotes here because I realize that there are many different ideas and many different options depending on body type, diving style, and preference. Talking ideal trim is probably like asking whether or not I should buy split fins.

**Note: It seems that if you're having nerve pain in your groin due to your bike seat, the intuitive response would be to lower the nose of the seat to alleviate pressure built up there. However, the actual way to alleviate that pressure is to tilt the nose up slightly. This seems counter-intuitive, but it works thanks to the anatomy of how we sit on bicycle seats.

If your trim is nearly there and only slowly rotates when you're static, don't be too tempted to make major overhauls, just small tweaks. You mention that you moved your cylinder position; was this to correct the rotational effect? If so, did it help? Also, are you using a steel or ali cylinder?
 

Back
Top Bottom