Kinetic Chain Questions

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fozzy40

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My understanding about the differences between open vs. closed kinetic chain exercises is whether or not the distal segment is fixed.

I was at working out the other day alternating pull-ups on free hanging rings and also on the pull up bar. There is an obvious difference in the amount of effort it takes to do a pull up between the two different apparatuses. I'm assuming it's because you are recruiting more and different muscles to stabilize the entire arm and bring it through full range using free-hanging rings compared to a fixed pull up bar.

My questions are:
1) Is performing a pull up on a fixed bar considered a closed kinetic chain exercise?

2) Does that make free hanging ring pullups a "more open" chain vs closed chain exercise?

fozzy40
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fozzy40 said:
My questions are:
1) Is performing a pull up on a fixed bar considered a closed kinetic chain exercise?

2) Does that make free hanging ring pullups a "more open" chain vs closed chain exercise?
Click to expand...

I would call both closed chain because the distal extremity (the hand) is still fixed as you move your body through space. The added difficulty is due to added instability and is a separate issue from the closed/open chain issue. Compare it to squatting on foam instead of a hard floor; it is harder on foam because the surface is unstable and allows for some movement, but both instances are both still closed chain. Same applies to your example. And I would never refer to something being "more" open or closed because I don't consider it a continuum. It's either open, closed, neither, or a more complex exercise that incorporates both IMO.
 
Interesting..
So if doing a squat on a hard vs. an unstable surface are both CKC exercises, what is the difference between the two since there are obvious differences in difficulty. Is it that you are recruiting different muscles to help stabilize more degrees of freedom at the ankle? I guess on some level I wonder if there is some sort of continuum where an OKC exercise has the most degrees of freedom.
 
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fozzy40 said:
Interesting..
So if doing a squat on a hard vs. an unstable surface are both CKC exercises, what is the difference between the two since there are obvious differences in difficulty. Is it that you are recruiting different muscles to help stabilize more degrees of freedom at the ankle? I guess on some level I wonder if there is some sort of continuum where an OKC exercise has the most degrees of freedom.
Click to expand...

The difference with standing on foam is that your ankle and foot are not entirely static. Depending upon your balance among other things, your body has to correct for the "mistakes" that shift your COG on the foam. These correction strategies can happen at your ankle, knee, or hip and are a whole separate issue. But more simply, yes, you have to recruit other joints and muscles to maintain upright standing, which is more work for the individual.

I'm not sure I understand your last statement about a continuum, but I would say that in general, OKC exercises do allow more degrees of freedom because your distal extremity is free to move through its ROM while stabilized proximally. In CKC, you are typically more limited by the way that your body can move around a fixed distal extremity due to weight bearing and balance.
 
In CKC you have to move at least 2 joints. For example in a squat if you bend your knees, the ankles and hips have to move. The pull up is CKC - you can't only bend your elbows or shoulders. They both have to happen. In OKC movements it is possible to only move 1 joint.

Maybe there are exceptions, but this "definition" is working for me at the moment. (FYI - 1st year, 1st semester).
 
Are you sure about OKC being limited to just 1 joint? I see what you are saying if you are talking about seated knee extension exercises. But if someone is performing a front kick where you are getting lumbar spine, hip, knee, and ankle, isn't this an OKC?

Great discussion!
 
Liz- if you don't want your bubble burst look away now.

The closed chain refers to the proximal segment moving on the FIXED distal segment, for simplicity, a weight bearing position. This occurs when the femur moves on a fixed tibia during a squat.
The open chain refers the opposite- where the distal segment is moving on a fixed proximal segment as in a knee extension extension exercise where the tibia moves on a fixed femur.

There does not have to be two joints involved in a CKC chain movement, although there almost always is- a good example would be a calf raise (assuming you could keep the forefoot fixed).

Now as far a as a pull up goes that gets kind of messy because you have a closed chain at the elbow where the humerus moves on the fixed ulna while at the shoulder you have a Reverse action moment occurring between the humerus and the glenohumeral fossa.

This stuff can really hurt your head but when you are dealing with a patient who has an intra-articular issue such as a ligament reconstruction or tear this becomes EXTREMELY important in keeping the joint stress safe and out of harms way... open chain ACL rehab occurs at 90-45 degrees while closed chain occurs at 0-45. Get this backwards and you've got a screaming patient and a pissed off surgeon.
 
Thanks for the elaboration since I'm not at the real application part yet.

I was way over-simplifing things without explaining my thought process. First, I was assuming the fixed/weight bearing part was understood.
Second, I wasn't saying that OKC is only 1 joint - but that it can be whereas CKC is almost always more than 1 joint.
For a squat (CKC), you can't separate the knee flexion from the hip and ankle flexion without falling over.
However, kicking (OKC) involves multiple joints of course, but you could in theory get from point A to point B by moving 1 joint at a time: flex knee, flex hip, extend knee, flex lumbar spine.

Lastly, maybe this doesn't work for you. I apply this concept (within reason) as a way to test my decision of whether something is OKC or CKC. I didn't intend to define it. Rather to provide another way to think about it from my "fresh" perspective. I was sure to provide the caveat that I'm a 1st year student so that no one takes my post too seriously.
 
haha liz you have a very good and thorough thought process stick with it and you will be good to go. But some food for thought... what about a dead lift in which the ankle remains neutral, the knee remains in full extension, and the movement occurs as the pelvis is moving on the fixed femur?
 
You've definitely got me thinking.

My response at the moment is that the ankles cannot be fixed in a deadlift. As you bend forward to grab the weight, your hips shift posteriorly and the ankles slightly plantarflex. So the opposite has to occur on the way back up to maintain balance. They ankle/hip motion has to occur together unless there is something I'm not considering.
 
CKC and OKC are not necessarily concrete terms. An activity can be considered CKC if the distal end of the limb is "relatively" more stabile than the proximal segment. The example of squats on an uneven surface is certainly a CKC activity.

Ponder this: Two people are standing on ice with a rope between them. One person weighs 200 pounds, one weighs 190. they have the same skates on and the skates are pointing at each other. they have a rope and they both pull on the rope. Who is going to move more? The one that weighs 190. It is a closed chain exercise for both of them but it is "more" closed on the heavier person.

It isn't always black and white.
 
Great example...I figured that these terms were not concrete and just a way to name general concepts.

So is the general reason why OKC put more force through joints is because it takes more muscle recruitment to stabilize? I'm guessing this is why in an acute injury/joint reconstruction that you would want OKC exercises limited to ROMs where structures are stressed the least and vice versa. Is this right?
 
fozzy40 said:
Great example...I figured that these terms were not concrete and just a way to name general concepts.

So is the general reason why OKC put more force through joints is because it takes more muscle recruitment to stabilize? I'm guessing this is why in an acute injury/joint reconstruction that you would want OKC exercises limited to ROMs where structures are stressed the least and vice versa. Is this right?
Click to expand...

My thinking is that the OKC are often isolating muscle groups vs integrating them. For example: short or long arc quads do not load any muscle group other than the quads to achieve terminal extension. This applies a large compressive load on the patella since the mechanical advantage is so poor at the knee, especially in the last 30 degrees where the patello-femoral contact area is the smallest. Contrast that to a squat done correctly (universal athletic position) with knees behind toes and butt behind feet. The quads are activated, but so are the hamstrings, gluteals, and calf mm. So, the quads try to extend the knee, the hamstrings extend the hip, the gluts extend the hip and the calves plantar flex the ankle (with the foot on the ground, this equals knee extension) and the force is distributed over many groups.

I rarely do OKC with the LE only because it is not terribly functional. e.g. the only time you do a resisted SLR is when someone tucks the sheets into the bed too tightly when they make the bed and it curls your toes down. You might do a SLR to untuck the sheet.

Injuries don't occur with the foot in the air so I spend my patient's therapeutic time with their feet on the ground training proprioception and efficiency at the same time that I strengthen them. Kill several birds with fewer stones. I find that it is more important to teach the muscle(s) when to contract and who to play with rather than simply to be stronger. It doesn't matter how strong a muscle is if it contracts at the wrong time.
 
Thanks again to everyone contributing to this discussion. Very helpful!
 
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