Why does developing the quadriceps help knee arthritis?

Discussion in 'Health & Fitness' started by Raul_SJ, Feb 10, 2013.

  1. Raul_SJ

    Raul_SJ Professional

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    Given that developing quadriceps muscles does not reduce the impact on the knee joint, how exactly does it serve to reduce knee osteo-arthritis progression as this recent study indicates?

    http://www.ncbi.nlm.nih.gov/pubmed/23192791

    Abstract

    OBJECTIVE:

    Although there is evidence for a beneficial effect of increased quadriceps strength on knee symptoms, the effect on knee structure is unclear. We undertook this study to examine the relationship between change in vastus medialis cross-sectional area (CSA) and knee pain, tibial cartilage volume, and risk of knee replacement in subjects with symptomatic knee osteoarthritis (OA).

    CONCLUSION:

    In a population of patients with symptomatic knee OA, increased vastus medialis size was associated with reduced knee pain and beneficial structural changes at the knee, suggesting that management of knee pain and optimizing vastus medialis size are important in reducing OA progression and subsequent knee replacement.
     
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  2. Chas Tennis

    Chas Tennis Hall of Fame

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    These pertain to arthritis of the patellar-femoral joint (injury under the knee cap) and not to the main joint of the knee. Injury to the patellar-femoral joint is often caused by quad muscle imbalances.

    Patellar-Femoral injury from poor tracking.
    http://www.youtube.com/watch?v=xWC4fLSSV6E

    Tight Rectus Femoris (the only quad that originates above the hip joint). I had and may still have tight rectus femoris muscles even after many years of playing tennis. (Because you play mostly in the 'ready position' with the femur to trunk angle flexed and the rectus femoris shortened.)
    http://www.mrtherapy.com/articles/article3.html

    General anatomy and function of the knee joint.
    http://www.youtube.com/watch?v=_q-Jxj5sT0g
     
    Last edited: Feb 10, 2013
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  3. ollinger

    ollinger Legend

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    The study is correlational and does not present a reason for the finding, at least not in the abstract. Possible explanations here are numerous. Moderate levels of activity, such as walking or going to a gym (i.e. not the pounding of tennis, necessarily) are thought to help resurface the cartilage in a joint, and the muscle size here may reflect that activity. We don't know from the abstract if diet was controlled for in the study -- could be that those who ate more adequate amounts of a nutient had that reflected in both muscle size and joint cartilage. Finally, one has to be careful interpreting the results of a study when the authors write "After adjusting for confounders" in discussing the data analysis. This means that some subjects were excluded before they did the data analysis because they were felt to be too deviated from the bulk of the subjects' results, not necessarily a valid thing to do before analyzing your results.
     
    Last edited: Feb 10, 2013
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  4. Raul_SJ

    Raul_SJ Professional

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    I think this latest study pertains to the main knee joint in general... there are two different studies.

    1) http://www.ncbi.nlm.nih.gov/pubmed/22248804

    The effects of quadriceps strengthening on pain, function, and patellofemoral joint contact area in persons with patellofemoral pain.

    2) http://www.ncbi.nlm.nih.gov/pubmed/23192791

    Increase in vastus medialis cross-sectional area is associated with reduced pain, cartilage loss, and joint replacement risk in knee osteoarthritis.
     
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  5. OHBH

    OHBH Semi-Pro

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    Stronger muscles simply hold the bones, ligaments, and other connective tissues in their proper place better than weak muscles. This prevents excess joint movement and wear. I thought this was joint protection 101.
     
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  6. Chas Tennis

    Chas Tennis Hall of Fame

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    Stronger muscles can contribute to muscle imbalances. These can cause knee problems.

    Are bad knees caused more by getting older or from years of tennis with a muscle imbalance?

    [​IMG]

    Illustrations muscle imbalances

    https://www.google.com/search?q=mus...vJaq20QH7tIGQCw&ved=0CDcQsAQ&biw=1334&bih=722
     
    Last edited: Feb 12, 2013
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  7. Chas Tennis

    Chas Tennis Hall of Fame

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  8. OHBH

    OHBH Semi-Pro

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    Well you obviously need all the muscles to be strong for stability, but the greater majority of people are stronger in the posterior leg muscles causing the types of imbalances that contribute to the most common knee problems.
     
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  9. Chas Tennis

    Chas Tennis Hall of Fame

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    Interesting - Do you have some links discussing that the majority of people have stronger posterior leg muscles and how that affects the knees? How about for tennis players?
     
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  10. OHBH

    OHBH Semi-Pro

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    After a looking into my National Council on Strength and Fitness textbook the strength ratio between the knee flexors to knee extensors is ideally 2:3. Regarding posterior leg strength, tightness and hamstring flexibility are the real problem as everyday activities such as running, sitting, etc make the hamstrings much tighter than they should be. Quad strengthening exercises force the posterior muscles to relax and even get a mild stretch balancing the pulling forces on the knee which are coming from these antagonistic muscle groups.
     
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  11. BeHappy

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    It's simply because when you sprint you are pushing against the resistance of the ground with your hamstrings, but there's no resistance when your legs swing forward through the air. That's why the imbalance happens.
     
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  12. Chas Tennis

    Chas Tennis Hall of Fame

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    Some links on these points would help me understand what you mean.
     
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  13. BeHappy

    BeHappy Hall of Fame

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    The resistance of pushing your leg against the ground builds the strength of your hamstring, there is no resistance for your quadricep as it swings your legs forward.

    What don't you understand?
     
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  14. OHBH

    OHBH Semi-Pro

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    The most common movements; walking, running, and sitting contribute to tight posterior muslces. The sedentary population (those who do not exercise) never get enough exercise in their anterior leg muscles. Lifters and football players (guys who do a lot of squats) don't have this problem, though they to often find other ways to screw up their knees.
     
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  15. Chas Tennis

    Chas Tennis Hall of Fame

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    I am getting mixed up. The above abstract does not discuss general quad strengthening but vastus medialis strengthening.

    Patellar Femoral Joint. Vastus medialis problems (weakness?) are well known to contribute to patellar-femoral joint problems. The balance between the vastus medialis and the other 3 quad muscles causes patella misalignment and tracking problems and that leads to cartilage damage. I have that cartilage damage and it is very common.

    My Dr mentioned that one possible cause for pain under the knee cap is an imbalance between the vastus medialis and the other 3 quad muscles (possibly also the hamstring antagonists?). This vastis medialis issue is well known, searchable. However, in my case, I believe that rectus femoris tightness, correctable by stretching, is the problem for me. See reply #2. When I stretched the rectus femorus my knees felt better and anterior pelvic tilt decreased very noticeably.

    Main Knee Joint. The abstract deals with the effect of strengthening the vastus medialis on the main knee joint. I don't believe from the abstract alone that the paper deals with strengthening the quads in general - all four quads. Exercises can emphasize only one quad, for example, by squatting with the feet positioned in some prescribed way. The vastus medialis could be preferentially strengthened and the balance between the 4 quad muscles would be changed. If muscle balance is restored between the 4 quad muscles and possibly also the antagonist hamstring muscles it seems reasonable that strengthening the vastis medialis might affect the pressure distribution within the knee joint.

    Discussion VMO (Vastus Medialis Oblique)
    http://ezinearticles.com/?The-VMO--...in-Relief-and-Knee-Joint-Stability&id=1726206

    Exercises VMO. The introduction mentions initial muscle firing time between the VMO and another quad muscle as an issue.
    http://wvuscholar.wvu.edu:8881//exl...zL2R0bC9kM18xL2FwYWNoZV9tZWRpYS8xNDA0Ng==.pdf

    The quads-
    [​IMG]
     
    Last edited: Feb 14, 2013
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  16. TennisLovaLova

    TennisLovaLova Hall of Fame

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    It is possible to develop quadriceps without hurting the knees.
    When you do squats, you have to put all your weight on the heels to avoid knee injuries.
     
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  17. Raul_SJ

    Raul_SJ Professional

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    I am going to try the "Leg Extension" exercise machine at the gym and see how it feels on the knees.

    Also need to check out if it develops the entire quadriceps or particular quadriceps muscles...

    If the study is correct, developing the vastus medialis improves the prognosis
    of knee arthritis.
     
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  18. Chas Tennis

    Chas Tennis Hall of Fame

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    Could you see the full publication?

    I had a Dr evaluate my leg posture mainly to improve long term recovery for meniscus cartilage injury and patellar femoral damage seen on MRIs. The Dr mentioned imbalances in quad muscles, particularly the vastus medialis, as one possibility for patella tracking cartilage damage. He also gave me a test that indicated my gluteus medius, and other muscles were weak and that posture issue could affect my knee joint risk. I searched the internet myself on quads and patella tracking and found the issue of tight rectus femorus. During physical therapy I discussed tight RF with my physical therapist. She said that tight rectus femorus muscles are a common problem especially among the older population. Tight RF is a cause of anterior pelvic tilt that gives an overall more bent-forward posture including head forward. She said that she frequently sees this bent forward posture in older patients.

    (BTW - In my opinion, many people associate that posture with getting older but it's often just anterior pelvic tilt caused but a tight rectus femorus. It's correctable by a few weeks of stretching. Warning - Back stress from the stretches??? I think mine was too tight for 20 years.....)

    These posture issues probably would not have been normally looked at during my treatment for a torn meniscus. But I was worried both about the long term knee joint posture and especially the patellar femoral injury on the MRIs that, in my opinion, were not being addressed.

    There are exercises and specific ways to perform them that strengthen the muscles while minimizing stress on injured joints and other areas. That is where a medically training physical therapist is critical.

    My physical therapy involved strengthening muscles in my hips and stretching the RF and some other muscles. Fortunately, there was no heavy quad strengthening exercises - a weak quad was not diagnosed or any physical therapy for it prescribed. A weak gluteus medius and some other things were corrected by the PT.

    Anyway, I believe that the whole story indicates the need when you get an injury for a well qualified Dr, a physical therapist, a solid diagnosis and a lot of your own internet research. Posture issues and already chronic conditions are very complex.
     
    Last edited: Feb 16, 2013
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  19. charliefedererer

    charliefedererer Legend

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    This is a, "Which came first, the chicken or the egg?" question.

    It could very well be that those who did not have as much knee pain were able to exercise more, and as a result developed the larger quads.

    Thus, rather than the increase in muscle mass being responsible for the decrease in knee pain, having less knee pain meant they could develop more muscle mass.
     
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  20. charliefedererer

    charliefedererer Legend

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    DO NOT DO THE LEG EXTENSION MACHINE TO STRENGTHEN YOUR QUADS!!!

    [unless you have hopelessly weak quads as in coming back from an injury or a stroke.]


    "To use the leg extension machine, you sit with a pad across your shins, and you extend your knees against the resistance. It works the muscles in the front of your thighs (the quadriceps), and even though you certainly feel it working, the risk may out­weigh the reward. Specifically, the LifeFitness Leg Extension exercise increases the force on the knee joint, especially the kneecap. In addition, it also puts unnecessary pressure on the ligaments and may damage knee cartilage.

    Another aspect to consider is that this machine is not “functional.” Functional activities are exercises that prepare you for move­ments in normal daily activities. The leg extension machine doesn’t mimic any movement that we encounter in real life and does not challenge your balance, coordination, or functional strength.

    There are better alternatives to the leg extension. Squats, lunges, and the leg press machine are other exercises that work your quadricep muscles, but don’t neglect the surrounding muscles, and work in a functional pattern. The load or resistance is distributed throughout the foot, ankle, knee, and hip. This is the way we move in real life, so why not train like it?

    All in all, because of the risk of the LifeFitness Leg Extension machine (machine #22 on the fitness floor), the management has decided to replace it with an additional Leg Press machine. We hope that you understand this decision and are able to adapt your routine to make it safer and more functional."
    - http://uncwellness.com/2013/01/leg-extension-machine-to-use-or-not-to-use/


    [​IMG]

    In fact, if I were a diabolical mad scientist that wanted to hurt peoples knees and develop a machine that would cause chondromalacia patella - a painful arthritis of the underside of the kneecap - I would force people to use the leg extension machine with weights high enough to develop quad leg strength.que

    The machine sets up the anterior knee as a fulcrum to drag the underside of the patella (kneecap) across the top of the femur (leg bone) under a great deal of tourque.


    The only place for the leg extension machine is with ridiculously light weights to begin functional leg extension therapy with those who have severely weak legs from illness or stoke.
     
    Last edited: Feb 16, 2013
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  21. charliefedererer

    charliefedererer Legend

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    I do BOTH squats AND deadlifts to do functional exercises that besides strengthening my quads, strengthen the hamstrings at the back of my legs to prevent a muscle imbalance.

    Plus, squats and deadlifts strengthen the core, AND THE MUSCLES THAT CONNECT THE CORE TO THE LEGS. - what machine does that?




    While I mainly do HIIT by running, I also do some on a stationary bike - the quads get a great workout on a bike, and the legs are trained to move up and down pretty fast.
    (Can't pedal at 250 rpm like Sampras though.)
     
    #21
  22. tlm

    tlm Legend

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    Listen to this post, charlie is exactly right. This guy knows what he is talking about.
    I was having problems with arthritis in my left knee last year. After researching a lot I decided to start doing squats again. My knee pain now is completely gone, I do squats 3 times a week and so far it has worked for me.

    I am 57 years old and play tennis 5 days a week, but I also weight train 3 days a week. I could not play tennis as often or as hard as I do without the strength training.
     
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  23. Raul_SJ

    Raul_SJ Professional

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    Yes, I think Charlie is correct.

    The leg extension machine feels quite uncomfortable on my knee joint, especially with higher weights.

    OTOH, I tried the squats and it feels relatively painless and I feel a difference the day after.
     
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