Wobbly frog kick

[TSandM]

I have a minor difficulty that is driving me nuts.

At the end of a full frog kick, just after the fins have more or less come together, I have a "wobbly moment". I just feel a little off balance, like when you're not going fast enough on a two wheeled bicycle, and I often end up moving one fin or the other a little bit to stabilize, before starting the loading portion of the next kick cycle. I talked to one of my buddies, and he says he notices the same thing sometimes.

Anybody got any clues as to what's going on? I was really noticing this in Mexico, diving double Al80s in a wetsuit. My weighting's spot on, and my buoyancy and trim are solid. I don't think the "wobble" is really even visible to my buddies. HERE's some video which includes some of me (I'm the one with the orange wing and the wetsuit).

If anybody has any ideas on this, I'm all ears.

 

[shoredivr]

Great video, love the halocline....

From a biomechanical viewpoint, there are two main actions in each frog kick. The first one is adduction at the hip (what you see: bringing the knees more together) combined with external rotation at the hip (what you see: soles of fins come together).

The second one is the repositioning for the next cycle: abduction at the hip (what you see: knees come more apart) combined with internal rotation at the hip (what you see: fins move away from each other).


In addition there's a minor internal and external rotation at the knee (in anatomical terms, the "screw home mechanism at the knee" )

If you want to look them up in an anatomy text:

hip adductors: adductor magnus, adductor brevis, adductor longus, etc
hip abductors: gluteus medius, gluteus minimus, etc
hip external rotators: piriformis, quadratus femoris etc
hip internal rotators: tensor fascia lata

screw home mechanism:
medial tibial rotation: popliteus
lateral tibial rotation: biceps femoris

Travell, MD, J. and D. Simons, MD, Myofascial Pain and Dysfunction, the Trigger Point Manual, Vol 2, 1992, Williams and Wilkins.This is a great reference book, can't recommend it highly enough for these kind of things.


If any of these muscle groups are either:

weak

or short

compared to others, you'll get asynchronous movement.

Often, piriformis is the culprit, being short and/or weak. That's what I thought I saw in the video. And this:

At the end of a full frog kick, just after the fins have more or less come together, I have a "wobbly moment". I just feel a little off balance, like when you're not going fast enough on a two wheeled bicycle

would tend to support piriformis as a causal factor, too.

In addition, you may have reduced range of motion in the hip joint or sacroiliac joint; or previous history of knee sprains, which could add to muscle overuse: if a ligament is strained, muscles have to work harder to support the joint.....

Come on over, I'll assess the length and strength of these muscle groups for you...set up a stretch/strengthen programme

If you like, I'll PM you some specific muscle length etc tests, you just need Peter to help out with them....

 

[Charlie99]

If you stay in that "end of kick cycle" position long enough without moving, will you turn turtle??

In the couple of times I tried a BP/wing with thin wetsuits, all of the backplate weight up high wanted to flip me tank side down. Worst case was shallow at the end of a dive with little or no air in the wing. The feeling was most obvious at the end of the glide of a frog kick. It bothered the heck out of me, even though it was not obvious to my buddies unless I stayed horizontal and absolutely motionless for 5+ seconds and even then they just thought that for some reason I was doing a quarter turn roll to look at something.

If the above describes your problem, then the solution is simply to move some of the weight from the plate down to weights on the front of your weightbelt.

 

[do it easy]

It wasn't brick-in-the-head obvious to me in the video, but I notice a wobble when I swim slowly and especially when I pause in the glide between kicks- I always assumed it was a balance mechanism to keep stable while gliding. I think different parts, such as pockets, bottles, lights, and even your wing, will drag differently through the water and cause you to be unstable. You might not notice it when still, since there is no flow to cause drag.

 

[AndrewJD]

I hear KMD has a strong frog kick.... perhaps he can provides some advice....

 

[TSandM]

KMD's the one who told me he sometimes experiences the same thing.

Charlie, no, I won't turn turtle. I can sit perfectly still and quite stable for some time before I have to move anything. I've really got my weight and posture worked out for good balance. (I got actual, spoken PRAISE for my buoyancy and trim from a GUE Cave instructor this last week )

Shoredivr, I suspect you're probably on the right track. I've had a bunch of lower extremity injuries (tibial plateau on the left, plafond on the right, among others) and I'm sure I have some muscle asymmetries. I've been doing strength work, but it may not be evening me out very well.

This is such a minor thing, but it just BUGS me.

 

[Thalassamania]

Lynne, think about keeping your knees closer together as you cock your legs for the stroke. As you release your legs into the propulsion phase of the kick, try and rotate your angles more so that your toes are further from the midline. Let me know if that helps or hurts ... but do practice a good bit before you decide.

 

[karstdvr]

Great video, love the halocline....

From a biomechanical viewpoint, there are two main actions in each frog kick. The first one is adduction at the hip (what you see: bringing the knees more together) combined with external rotation at the hip (what you see: soles of fins come together).

The second one is the repositioning for the next cycle: abduction at the hip (what you see: knees come more apart) combined with internal rotation at the hip (what you see: fins move away from each other).


In addition there's a minor internal and external rotation at the knee (in anatomical terms, the "screw home mechanism at the knee" )

If you want to look them up in an anatomy text:

hip adductors: adductor magnus, adductor brevis, adductor longus, etc
hip abductors: gluteus medius, gluteus minimus, etc
hip external rotators: piriformis, quadratus femoris etc
hip internal rotators: tensor fascia lata

screw home mechanism:
medial tibial rotation: popliteus
lateral tibial rotation: biceps femoris

Travell, MD, J. and D. Simons, MD, Myofascial Pain and Dysfunction, the Trigger Point Manual, Vol 2, 1992, Williams and Wilkins.This is a great reference book, can't recommend it highly enough for these kind of things.


If any of these muscle groups are either:

weak

or short

compared to others, you'll get asynchronous movement.

Often, piriformis is the culprit, being short and/or weak. That's what I thought I saw in the video. And this:

would tend to support piriformis as a causal factor, too.

In addition, you may have reduced range of motion in the hip joint or sacroiliac joint; or previous history of knee sprains, which could add to muscle overuse: if a ligament is strained, muscles have to work harder to support the joint.....

Come on over, I'll assess the length and strength of these muscle groups for you...set up a stretch/strengthen programme

If you like, I'll PM you some specific muscle length etc tests, you just need Peter to help out with them....

Piriformis...gemeulus inferior/superior,quadratus femoris,obturator internus/externus are weak external rotation movers versus Glut max,they serve more in a capacity as a shunt muscle versus spurt muscle. The screw home mechanism of the knee probably plays a very minor role,but ankle inversion/eversion from a control of roll/yaw probably play a bigger role.

 

[karstdvr]

I have a minor difficulty that is driving me nuts.

At the end of a full frog kick, just after the fins have more or less come together, I have a "wobbly moment". I just feel a little off balance, like when you're not going fast enough on a two wheeled bicycle, and I often end up moving one fin or the other a little bit to stabilize, before starting the loading portion of the next kick cycle. I talked to one of my buddies, and he says he notices the same thing sometimes.

Anybody got any clues as to what's going on? I was really noticing this in Mexico, diving double Al80s in a wetsuit. My weighting's spot on, and my buoyancy and trim are solid. I don't think the "wobble" is really even visible to my buddies. HERE's some video which includes some of me (I'm the one with the orange wing and the wetsuit).

If anybody has any ideas on this, I'm all ears.

What are your results when you do a modified flutter and shuffle kick?

 

[jagfish]

Hi Lynn
Great dive environment....I can definitely see the hitch you are talking about. Compared to your buddy (instructor?) you can see that you haven't fully developed your fluidity yet in that kick, possibly due to ankle/knee/hip flexibility issues. It's quite a contrast in the video.

I'm sure you'll get it...and kudos for you to open up yourself to this kind of examination....