Saturday, July 28, 2012

Healing Knees and Closed Chain Vs. Open Chain Exercises

This is a continuation of last week’s post, a success story with a twist near the end. Pat, who was suffering from knee pain, met a physical therapist who, upon hearing of how she improved by “walking small steps” around her apartment, approvingly said, “closed chain.”

So what are “closed chain” exercises, and are they the key to chasing away knee pain?

I had come across the closed/open chain terminology before, but never bothered to really look into it. Generally, I distrust geeks bearing jargon. I’m an Occam’s Razor kind of guy. When simple reasons explain phenomena as well as complex, why not keep it simple?

So I delved a little into the book, Closed Kinetic Chain Exercise: A Comprehensive Guide to Multiple Joint Exercise. I was far from an expert on the subject, but the same surely couldn’t be said of authors Todd Ellenbecker and George Davies.

Open-chain exercises, they tell us, isolate joint and muscle movements. Further, the movement pattern is “often nonfunctional.” And the “distal end of the extremity is free in space.”

To understand these points better, consider a pure open-chain exercise -- the seated leg extension (that’s the one in the gym where you straighten your bent leg forward, against the resistance of weights). The “distal end” of the limb (that would be your foot) is out there in open space, not fixed to anything. The exercise recruits only a few muscles and joints. And functionally, well, it’s pretty much useless, unless your daily activities entail punting a football repeatedly.

So that brings us back to closed-chain exercises (such as squats). Are they then superior? Sure sounds like it.

However, it turns out that things aren’t that clear. Here I’m just going to step back and let the authors of the book explain.

First, the functional vs. nonfunctional distinction doesn’t exactly hold up after all:
One of the common arguments against the primary use of open kinetic chain exercises in the lower extremity is that they are not functional. For example, there are limited instances in the lower extremity where an individual functions in a seated position bending and strengthening the leg ... Closed kinetic chain exercises are considered to be more functional, because they closely simulate the actual movement patterns encountered in both sport and daily activities.
Analysis of most functional activities reveals that they are, in fact, a series of successive open kinetic chain and closed kinetic chain motions. An example is the normal gait cycle. During walking, approximately 65% of the gait cycle is weight bearing (closed kinetic chain) and 35% is non-weight bearing (open kinetic chain). Interestingly, during running, the percentages of closed and open kinetic chain motions essentially reverse.
Further complicating matters:
Activities progress along a continuum from closed to open kinetic chain, with many activities of daily living and sport activities incorporating components of both. For example, during the gait cycle, the stance phase is a closed kinetic chain pattern, whereas the swing phase is an open kinetic chain pattern. Another example that shows the interplay between these two movement patterns is riding a bike, during which the foot is fixed on the pedal in a closed kinetic chain pattern, yet the pedal and foot freely move in space. Another example is skiing, where the feet are fixed to the skis (closed kinetic chain), but the skis move on the snow and are not fixed to an object (open kinetic chain).
What’s more, some purported benefits of closed-chain exercises may not actually exist:
Many clinicians have assumed that in the closed kinetic chain position of the lower extremity there is automatically a resultant co-contraction of the muscles that should dynamically stabilize the knee joint. Although some studies did demonstrate this phenomenon, several recent studies actually refuted that significant co-contractions occur with some closed kinetic chain exercises.
Finally, in conclusion, I found this quoted comment (my bold) from other researchers (cited as Snyder and Mackler; sorry I didn't get the full footnote) quite interesting. It refers to rehabbing after surgery to repair the anterior cruciate ligament, but I think the phrase “after reconstruction of the anterior cruciate ligament” could easily be replaced by lots of other phrases, such as “for patients with chronic knee pain.”
Rehabiliation after reconstruction of the anterior cruciate ligament continues to be guided more by myth and fad than by science ... The present study ... suggests that closed kinetic chain exercise alone does not provide an adequate stimulus to the quadriceps femoris to permit more normal function of the knee in stance phase in most patients in the early period after reconstruction of the anterior cruciate ligament.
Now if all this “open chain” vs. “closed chain” stuff sounds a bit faddish, well, the physical therapy trends (according to the authors) looked like this:
1970s Functional rehabiliation
1980s Open kinetic chain exercises (with emphasis on isokinetics)
1990s Closed kinetic chain exercises
How’s that for inducing whiplash? The same physical therapist you saw in 1985 who was saying, “You gotta do open chain, open chain, open chain,” ten years later was probably saying, “You gotta do closed chain, closed chain, closed chain.”

My personal take is that you need to do gentle, high-repetition activities (and if they’re functional, so much the better) to heal bad knees, giving yourself lots of time to achieve results. I wouldn’t worry too much about where my activities lie on the open-closed chain continuum.

Full disclosure: I own a bike chain. I like it. It gets me places. :)


  1. Hello Richard, 

    I just read your book over the July 21 weekend. Thank you for sharing your story!   It is very validating of so many of my own (failed) attempts to heal my knee since 2006! Like you,  I used to be very active doing road biking,  windsurfing, waltzing,  downhill & cross country skiing, hiking, swing dancing, etc.  but I had to totally stop ALL of that for the past 6 years due to severe knee pain.  Walking was the only thing I could do -- and usually not too far. And sometimes even walking was too painful.  (Fortunately, I did not have pain sitting, so that was lucky!)   

    One big AH-HA was the section about how knees work and why I can do what I call "a high risk activity" (attempting to do a squat or ......jog 10 feet to catch the bus or ...... even stumble over a pebble on the sidewalk) and not experience any pain at the time... but then 24 hours later have a terrible setback and be in pain for weeks.  After figuring out this 24-hour pain delay problem, i would go to bed at night in fear and suspense wondering if I had "overdone it again" and would be in pain the next day and if it would be a 2 week setback or a month setback. 

    Another AH-HA was to read your idea about healing the joint first. I have had the exact same problem in your book where I would try to strengthen the quads and other leg muscles and it would seem to start to help, but.... I always always always have a flare up which caused a big, painful set back. Very frustrating!! 
    So, when I read your idea about gentle motion to heal the joint first and then finally, over time, slowly slowly slowly work on strengthening the leg muscles, it completely resonated! Yes yes yes!  

    I have more to say on all that, but for now I want to contribute to the conversation about  open and closed chain.

    After trying soooooo many things, for me personally what seems to have been the turning point starting in March 2012 was trying water therapy which is open chain.  (I want to clarify by water therapy I do not mean "swimming!"  So may people had told me "swimming is good for knees" but I tried it and of course I had a flare up.)  I finally read a book which talked about actual Water Therapy exercises including specific exercises for people with bad knees.  I started by wearing a flotation belt in the deep end of the pool and do gentle leg movements while suspended in the water (while wearing my knee brace).  This is open chain because I'm just floating. This turned out to be really really helpful!   Now I've built up to being in the shallow end with my feet on the bottom (closed chain) and I am trying  to build up courage to try what I call a "high risk" motions... like jumping with both legs while in shoulder deep water or even hop.  Eventually the idea is I'll be able to jump in progressively shallower water and some day I'll be able to jump or hop on land in full gravity. But, that won't be for a long while! 

    Before reading Saving My Knees I did not know about the idea of healing the joint before healing the knee. But now after reading Saving My Knees what I think was happening was that my knee joint liked the gentle motion without the strain of "strengthening the quads."  So, that helped slowly heal my joint and then later I was able to start adding in exercises to strengthen the quads and other muscles.

     I also started 5 minute gentle biking at the gym.... Then have been slowly building up to 7 minutes...10 minutes...Etc... Then in June started biking outdoors on flat... Now in July I'm starting to add in tiny hills. This is WONDERFUL!!!!  But it all started with the open chain water therapy

    1. That's great! I think water activities are often beneficial (though I had mixed results, myself). I think your experience further throws into question why the focus on closed vs. open chain. There are a lot of good rehab activities that can be done in the water that are open chain, even though some therapists recommend that knee pain patients stick with closed chain. The truth is, "open chain" water is very different from "open chain" land.

  2. I have a few things to say too. I read in the book Anterior knee pain and Patellar Instability that between 0º (extension)-50º of flexion closed kinetic chain excercises are less harmful to the knee, as they provoke smaller moment, lesser reaction forces, and smaller pressure in the patellofemoral joint.

    However, between 50º -90º of flexion open kinetic chain exercises are the ones with smaller movement, less reaction forces and less pressure. That's the reason why certain exercises should be done only between certain degrees of motion, as doing them the wrong way could make matters worse.

    As from my experience, I wasted many months doing seated leg extensions against resistance (open kinetic chain exercise, as it is said in this post) recommended by a doctor and they made my knee pain much worse. I think I'm not an isolated case as I read many patients without knee pain developed symptoms after this last type of exercise.

    Too Knee Pain: I tried water therapy for a month a year ago and my knee felt even worse. Reading you comment now I realize I overdid it. To put it short: beware of jumps (and impatience).

  3. Hello Richard,

    I wrote a message a few weeks back regarding how to deal with setbacks. Since then I have had some improvements and some setbacks as well, but I think overall I am more focused now on what has the potential to help me and what is certain to make things worse. I wanted to add a few things and maybe they would help someone. Please take them all with a very big grain of salt - their just my personal view.

    I believe what you say is true, that gentle movement is the key to healing. I think the other side of it is that it is also very important what we do when are passive - and we are bound to be passive some of the time. So a few things:
    Get a good bed - if you have even a small curve near the feat area, that can put unnecessary stress on your knees for hours without you even noticing.
    Stay away from what feels bad - even if that means looking awkward. For example I try avoiding sitting on regular chairs because I found the constant unchanging pressure from the ground is bad for my knees. If I need a chair I use a tall bar chair where my legs have zero pressure from the ground (or if I sit partly they have very little pressure).
    Changing pressure points is very important for me. If I stand in line, it's better for me to walk in place or change my weight center regularly. Putting pressure on one point for a long period of time can hurt - even if you don't feel it right away.

    I have found this exercise routine quite effective (for me):
    Sitting on a high chair with legs not touching the floor.
    Wiggling my leg back and forth very softly starting with almost no range at all - using mostly inertia and gravity to move them. Then walking some steps around the house. Then repeating according to how I feel.

    It helps to learn how to stop exercising when you are still feeling well, how to handle yourself when you are in passive times and how to notice when things start to get worse.

    I find Nordic sticks for walking are helpful. They take pressure of the knees, they work the upper body. However be careful not to hurt your hands and not to do too much. They create the illusion that you are in better position then you really are, you can easily overdo it without noticing - your knees will notice it later.

    There are tables that electronically change their height! That allows you to sit or stand or anything in between. That seems fantastic for people with knee problems (and for everybody else). I do hope to get that someday.

    Above all, if you find something that works - try not to do too much of it. If you feel suddenly much better - keep being careful and attentive as you would be if you were still in pain.

    Good luck!

    1. Omer, I definitely relate to what you said about trying not to over do it. That is very difficult to gauge... especially because of the delayed pain effect. Do you have the delayed pain effect that Richard talks about in "Saving My Knees"? I definitely have that problem. It's very frustrating. I don't know I'm hurting myself until 24 hours later. I have to stop way way way before it starts hurting and even then it could be too late. I've been keeping a journal and one of the words that pops up a lot is Patience! Patience patience patience. Patience is frustrating, too, but not as frustrating as a huge set-back. But in my journal pretty much every day I remind myself to be patient and not over-do-it. I am famous for over-doing-it. Yesterday I told two friends about how well I've been doing on my current knee therapy exercises and my plans, but instead of looking happy for me they both looked very scared and said, "don't over-do-it!" I guess I don't blame them for their reaction. I've had so many ups and downs caused by accidentally over-doing-it... I wonder if there is anyone left who believes I can be healed instead of having a setback to square zero. I am trying so hard to be careful and patient this time. Again.

      You mentioned that you are worried about hurting your hands with the Nordic stick. I am not sure what you mean by a Nordic stick. I have a walking stick that I used sometimes. What they taught me to do is to hold the strap in such a way that my hand is totally supported by the strap. In this way, I'm not gripping the stick with my hand (which would be very tiring), but the downward force of my hand on the strap means my hand, wrist and whole forearm are all all involved in stabilizing the stick so, my grip on the stick is much much lighter. I hope this helps.

    2. Omer, these sound like some good tips. I'm glad you mentioned the walking sticks. They can be useful and they make sense to me, in terms of taking pressure off the joint.

    3. Thank you both.

      Knee Pain, I think the delayed pain is one of the hardest things to deal with - but I believe it is possible to deal with (and Richard is a living example).
      Here's my take on it:
      1) Go by experience - try to remember what is too much, 2) Try to remember what was just right and did not cause any pain (just as important).

      Low impact exercises, with little weight bearing, can be done much longer without damage. So when in pain I think one should try to do more of those, while very gradually increasing the weight bearing activities.
      It's not a crime to walk just a few steps once in a while, it's far better than "proving" you can walk a certain distance while hurting your knee.

      3) Be very sensitive to small pain. Be just as sensitive to comfortable sensations.

      4) Get a program that reminds you to walk away from the computer... very useful (i use workrave it's free)

    4. I love this idea about a reminder to move away from the computer!

      Also, I totally agree with what you are saying about not worrying about "proving" I can walk a certain distance. It's all about how my knee is doing right at that moment and paying attention to it rather than thinking "well I should be able to walk 3 miles because last time I waked 2.5 miles." maybe right at that moment my knee needs just 1 miles or 1/2 mile.

  4. Hi Richard,

    Finished your book too fast probably and will no doubt have to re-read parts of it. At least reading is an activity that I can still do with intensity and doesn't that hurt my knees...

    Our stories are much alike: I too am now in my late 40's and was diagnosed with PFS 1 year ago, probably because of too much climbing over a six year period (there's a 4 mile climb @ 8% near my house that I got in the habit of climbing, literally hundreds of times yearly due to time constraints). I've also had issues with my heart and had a mostly successful ablation 6 years ago, but can experience mild ectopy from time to time.

    There's no need to bore you with the details of my struggle to rehab, you are much more entertaining and articulate than I am and my path has been much like yours. One difference is that I "elected" to have surgery (lateral release and chondral shave) after 7 months of PT, reduced exercise, supplements, etc. Without getting into the sordid details, the surgery has been a disaster and now there is swelling on the back of my patella.

    Just got a second opinion as the original surgeon wants to scope and probe...No thank you very much. The second OS say's rest for six weeks, with light cycling. Unfortunately, walking causes the kneecap to lock, so rest with light cycling it is. I suspect though, particularly after reading your book, that 6 weeks is pretty optimistic and now I believe I am prepared for the longer haul with plan... As you can see I am still at a stage of acceptance.

    A flailing question for you about mold. I started having knee pain soon after moving into a house in the woods. The house hadn't been inhabited for over a year and there was a lot of mold that we removed. Even in summer we don't get a lot of sun (on the north side of a mountain and under the redwoods). When reading your book, noticed that you moved from Hong Kong (where you mentioned it was very mildewy/moldy in summer, which is when you became more symptomatic) in 2008 and if you think that there might be a possible link between your continued improvement post 2008 and your new environs?

    Thanks for your time. Will adhere to your advice and keep you posted.

    1. Good question about the mold. Did all the mold in my apartment somehow contribute to my condition, and did moving (and getting away from the mold) contribute to my recovery? My family asked the same question. And believe me, while writing the book I pondered practically everything, trying to figure out what happened to me and why.

      Honestly though, I don't think there was a connection between the mold and my bad knees (or if there was, it was very, very small). The strongest evidence I can cite: the year I got better I was living in the same moldy apartment. I stayed in Hong Kong for the first year of my recovery, and at the end of that year, I was well on my way to fully healing. About the nine-month mark (while living in Hong Kong), I felt pretty confident that my program was going to result in a full recovery, as I had gotten much better already.

  5. Looking at the quote above about the typical open chain activity just isolates one joint, that reminds me that when I first started doing the water therapy one thing that I thought was really great was that my muscles all gently worked together to make the movements: feet, shins/calves, hams, quads, hips...., maybe also back and core. I remember thinking that some muscles that I hardly ever use woke up and seemed to be grumpy and shocked that I was asking them to chip into the effort. They cramped up in protest.... Which i interpretted as a good sign! Also, it was fascinating that something as simple as pointing my toe or flexing my foot would change the way the other leg muscles worked as I moved my leg through the water. Also, if some movement seemed too intense all I had to do was move more slowly to make it less intense.

    I should probably stop and say that I am not a water therapist or any sort of therapist. I'm just a person who has tried many many things to heal my knees and was delighted and amazed that water therapy (not swimming!) seemed to make a huge difference for me. I am also very grateful and surprised the the public pool in my city has the flotation belts that I needed for these deep water exercises. Not only that, but, the public pool reserves time slots for a special swim lane to be ONLY for people who want to do therapy instead of swim laps. Wow! The life guards were also very supportive and have seen many people benefit from water therapy, which was encouraging to a newbie like me. That was very lucky I found that pool!

    Back to open chain or closed chain, do I think that the fact my water therapy was "open chain" exercise was really important? I don't know. All I can say is that I think that being able to move my knee without too much strain on the joint helped -- what Richard calls gentle repetative motion. Also, I think that it was very helpful to do gentle exercises that required my leg muscles to all work together as a team instead of "just the quads" or "just the hams."

    1. Just to be clear to everyone, a big part of the impetus for writing this blog post wasn't "I'm anti-knowledge, and I sneer at things I don't happen to understand." On the contrary: I love learning about new things. But on my long journey through knee pain, I felt at times like the complexity a knee pain sufferer has to wade through was just too bewildering (especially some of what you get from structuralists, when they concoct these chains of causation between various muscles and your aching knees).

      In my opinion, someone with knee pain has to be concerned with a lot of things about the activities they do -- the range of motion the bent knee goes through, the intensity of the exercise, how the foot lands, how the knee is stressed, etc. etc. But dwelling on whether that activity is "open chain" or "closed chain" just doesn't seem all that worthwhile to me. But of course -- I could be wrong and there may be something I need to be enlightened about!

    2. I hope I didn't imply that you were sneering at anything. And I hope I didn't sound as if I was sneering at anything, either.

      I'm so glad that you are willing to read the research and distill it down to th essentials for the rest if us!! Thank you!!

      I am reading through your 2 year of blog posts and am AMAZED (in a good way) at some things you have posted! Just now I found the Nov 20, 2010 post about the patella tracking problem and asking if my doctor was a structuralist. Like I wrote in my response, my jaw dropped!! That's been my entire knee history!! Most doctors told me the problem was my patella alignment. Only 2 suggested something else was causing my pain.