Heavy Fin Problems

[Surelyshirly]

with your rig balanced ..... placing your weights evenly up the configuration.... you should have the whole thing neutral and almost floating above you, not being carried by you.... your harness should not be so tight as to be restrictive and you should have room to flex slightly.... the fins hsould not be an issue with your knees bent close

is it possible that you are trying to support the whole rig and are causing yourself some discomfort?

I can tell you that I fractured my back this past year and if anyone was going to be uncomfortable in a harness it was going to be me..... I actually got some diving in while in my brace. With my orthpaedists permission I was able to remove the brace and dive because my rig was balanced and not supported by me and the water was the best thing for me because it hyper extended my back....( good dive buddies did some major lugging for me and I still thank them...) you should not be uncomfortable in the water

 

[shoredivr]

When you stand up while wearing tanks, straighten your body against the pull of the load and maintain a neutral spine. Do not tighten your abdominals; just move your pelvis.

I'm having a really hard time understanding Dr. Bookspan's instructions.

Imagine you're looking at a person from the right side, where A down to C represents your low back down to the back of your thighs. B down to D represents your abdominals down to the front of your thighs. The [......] represents your pelvic bones. The ** represents the muscles in your lower back. The 'I' represents your lumbar spine. The ! represents your abdominal muscles. The # represents your hamstring muscles. The & represents your iliopsoas and quadriceps muscles (deep hip flexors and front of thigh muscles).

A................B
* I .............!
* I .............!
[................] .
# .............&
# .............&
C...............D


In a general way, to keep the pelvis "level", the low back muscles and the abdominal muscles (*, !) must pull "up" equally to the hamstring and iliopsoas/quadriceps muscle's pulling "'down" (#, &).

I can't see how you can keep your pelvis "level"....therefore keeping your low back vertebrae (I) not hyperlordotic (less arched) WITHOUT tightening your abdominal muscles (! in the sketch above). The abdominals HAVE to pull up to keep the pelvis [....] level.

Sure, you can 'shift' your pelvis "neutral", but the abdominals have a role to play in this movement.

What am I missing?

 

[Diver Lori]

Post 17 may be where you need to look for answers. If you have to drop your knees ('bend my thighs at the hip downward, and knees upward to keep my fins up in the air.') to get relief, you have a configuration issue.

I don't have a problem with sinking feet, my legs float. I wear jets and they are just right, it's the arching the back that I can't abide. And I don't wear any weight with the SS backplate in a wetsuit, so there's no weight to move around. When my torso is straight from head right down to the knees, that's were the arching comes into play. Unfortunately, the DAN article has grapics (that aren't visible in the copy I posted) to show what a diver does which is my issue to a "T". I've got kickass buoyancy and can hover on a dime, I move through the water with minimal effort, I just can't arch my back without discomfort. When I say I bend my thighs downward and my knees upward, it's subtle and not an exagerated form.

Therefore, telling a diver to "arch" their back, not knowing their predispostion is iffy at best, and just may add a whole other set of issues, my case being an example.

 

[Diver Lori]

with your rig balanced ..... placing your weights evenly up the configuration.... you should have the whole thing neutral and almost floating above you, not being carried by you.... your harness should not be so tight as to be restrictive and you should have room to flex slightly.... the fins hsould not be an issue with your knees bent close

is it possible that you are trying to support the whole rig and are causing yourself some discomfort?

I can tell you that I fractured my back this past year and if anyone was going to be uncomfortable in a harness it was going to be me..... I actually got some diving in while in my brace. With my orthpaedists permission I was able to remove the brace and dive because my rig was balanced and not supported by me and the water was the best thing for me because it hyper extended my back....( good dive buddies did some major lugging for me and I still thank them...) you should not be uncomfortable in the water

My rig is balanced, and basically I hang below it. Whether I am diving backmount or sidemount, it's my back's position in conjunction with how my torso is bent at the hip that is the make or break.

Fortunately, I don't carry my rig in Mexico, as I hire someone to do it for me given some of the difficult entry areas. In Florida, I've gone sidemount for difficult entry areas, but still heft my own backmount for areas with steps. I was blessed with lower back issues (thanks Mom) that I have to be cognizant of. Fortunately the DAN article confirmed something I was already experiencing but didn't have a name for.

It's obviously an issue that is more common than thought if DAN has done an article on it. Maybe cases are on the rise due to heavier kits, and "ideal" trim, being less than ideal for the physiology.

Interesting.......

 

[GLENFWB]

I really appreciate all the information. I do have some mentors helping with this. I will be diving doubles and a wet suit to begin with. I currently do not have any weights to move because my steel tank and steel backplate make extra weight uncessary. I have to slide my tank "head-banging" high to get the trim I need. I have tried arching my back and pulling my knees up. I agree that I have some more work do to in the area of body position.

I am at a place in working on trim, that I don't know if the fins are causing me problems refining my trim....or my poor skills are causing me to blame the fins for the poor trim. I will continue to work on my body position, as well as testing some different fins.

 

[Meng_Tze]

Therefore, telling a diver to "arch" their back, not knowing their predispostion is iffy at best, and just may add a whole other set of issues, my case being an example.

I don't believe so, it is a standard and integral part of diving, especially in cave diving where absolute perfect trim is a must. Again, if arching ones back causes concern, the issues are not with diving, but deeper.

If advising someone to do something as a standard practice causes them pain, their participation in the sport may be iffy at best...?

 

[Diver Lori]

I don't believe so, it is a standard and integral part of diving, especially in cave diving where absolute perfect trim is a must. Again, if arching ones back causes concern, the issues are not with diving, but deeper.

If advising someone to do something as a standard practice causes them pain, their participation in the sport may be iffy at best...?

I find it very interesting your ability to argue your point with DAN and a physiologist, and discount all options save your own.

Go figure, live and let live.......

 

[TSandM]

I think part of the argument is coming from different interpretations of "arching the back". If you isolate the movement to the lumbar spine, you WILL end up with hyperlordosis and back pain. If you create the "arching" by minimizing the kyphosis of the thoracic spine, and going just past neutral in the lumbar region, you will create a situation where the backplate touches you at the top and bottom, but there's no pressure in the middle, and you can do this without aggravating your back. (And I speak as someone with disc problems, so I'm quite aware of back pain and what aggravates it, at least for me.) I like to think of making my body as "long" as possible, from my shoulders to my knees -- Trying to get my knees as far from my shoulders as I can produces just the right flattening of my torso, without hyperextension anywhere.

I do think a great many issues with trim in doubles are solved by posture. I know I moved weight around like crazy when I was first diving doubles, because I was head heavy. Nothing really solved it, but I did make it better. Nowadays, I can slap on a set of double 95s with cave fills and NO weight belt, and trim it out. I don't know exactly what I've learned to do differently, but I've learned something.

 

[ShagMan]

Glen, Mat encountered the same problem as you did, with the heavy Jets... he swapped to dive-rite fins as you know. Seem to be a common thing from what I can tell.

Skip doubles, go straight to side-mount!

 

[GLENFWB]

I thought about it...but going doubles for a while is much cheaper at this point.

Glen, Mat encountered the same problem as you did, with the heavy Jets... he swapped to dive-rite fins as you know. Seem to be a common thing from what I can tell.

Skip doubles, go straight to side-mount!