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SpecialistMichael, MS, CSCS
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I have am 67 and have to have knee replacements soon. Before

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I have am 67 and have to have knee replacements soon. Before I have surgery, what are some good cardiovascular toneing machines that do not stress the knees besides swimming and using the arms to pedal as in an "upper body bike"? I have heard of an eliptical trainers but have never been on one. I used to run 5 miles a day and be in the gym daily but that was until 1996 when I had an L2-S1 fusion causing chronic pain. I have not been to a gym since, due to chronic pain. With more surgeries coming up, both knees, then the L1-L2 disk, I want to tone up my cardiovascular system without stress on my back and especially my knees. What do you suggest?


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Hi Leslie,

Well what you will actually find once you have your knee replacements is that they will be putting you on a bike within days of the replacement surgeries.

I have seen and worked with tons of joint replacement patients and the very first thing is actually putting you on the bike to passively range the knee and see where you are at. Basically it allows you to very carefully activate the muscles of the thigh to work you(over time) into a usable range of motion.

So my first recommendations are going to be the standing bike and the elliptical and then followed by the recumbent(seated bike). The seated bike requires a little 'flexibility' per se to use, its slightly more uncomfortable for some people.

So with the bikes they will require a different "type" of cardio compared to running and compared to non impact elliptical. Bikes use the quadriceps muscles in such a way that it requires and trains a level of muscular endurance as the primary movers. Whereas with running and elliptical, its the BACK of the thigh doing the moving and the quad muscles(front thigh) actually almost act to stabilize the knee during the weight transfer.

So following your surgery, you will be taught by your therapists to fire your quads again, they will be forcing your knee not only into a bending range of motion but ALSO and very importantly into whats called a terminal extension(aka lockout). So to me its important to almost, pre-train that motion and muscular activation so that post surgery its already familiar and the muscles already are more ready to "help you" with the therapy.

So I would recommend the standing bike as well as the elliptical both which are non impact, the latter being weight bearing exercise that closely simulates running(which I'm sure you are anxious to get back to) but are awesome ways to build your cardio back safely while being kind to your joints.


Customer: replied 4 years ago.

That is great info, BUT I meant what can I do BEFORE surgery to get back some cardio and strengthen the muscles, ligaments and tendons around the knees, and without strain on L1-L2? I have chronic renal failure so now only weigh 145-150 pounds, which is my goal weight at 5'7". It is mostly flab. I want to spend a month "getting into shape" before the surgery for the best results. I have tried on my own but end up in bed because of the bad disk at the top of my fusion, L2-S1. My orthopedic surgeon recommends pre-op: leg press, thigh abduction, thigh adduction, leg extension to 45 degrees of knee flexion and calf curls. In this age of super specialization the orthopod is only concerned with the knees and not the back. I need a different orthopedic surgeon for the back!


To sum it up, I am mainly interested in what to do cardio-wise pre-op. I am a retired doctor, a D.O., if you know what that is- a combination of M.D. and chiropractor, so be as technical as you want.

I am still contemplating actually going back to D.O school - you are in good company.

So my opinion on training is something of a FUNCTIONAL one. I like to use and recommend exercises and activities that actually mimic(or partially mimic) human movement patterns. So the basics of these as you can imagine are squatting, exaggerated stepping(like lunging type movements) or and stair stepping stuff. THe other thing I like this for is that not only are they human movement patterns that are familiar both to you(so that you don't need to learn something complex) but also familiar in that its going to benefit you in your daily life.

All sports, ADLs and activities are based around these movement patterns both on the field(Obviously in combination) and in a training environment. So with this, the role of a performance professional, a rehab clinician or at the basic level the athlete, improving upon these patterns is what is going to get transferable results

That said, I don't personally like to recommend the leg extension. I try to get people to imagine dragging a rope with a hanging sandbag(the lower leg) over the edge of a building. Plus depending on the degradation of the articulation between the patella and the femoral notch, it might not be comfortable. I personally don't like them for myself and I have healthy knees aside from 2 smaller meniscal tears in each and a little bit of recurrent patellofemoral syndrome sometimes with my left knee. They just aren't comfortable. HOWEVER, if you feel them working your quads, and you are pain free while doing them I would say do them if you like them. It does isolate the quad, but keep in mind, there is nothing else in the day, aside fromt that leg extension, that is isolating that quad. I would guess these might be a little uncomfortable for you, maybe not, but see if you like them and go from there.

So back to the stuff i would recommend doing - you need a cardio component. Remember that the aerobic system provides recovery to muscles while they aren't working(in between both sets and workouts) so increasing your CV performance is definitely going to benefit you post surgically as well as during your workouts. For this I would warmup on the bike and get your body warm and the muscles warm. You could also do a portion of your cardio after the weight training sessions.

Exercises I would suggest would be a lunge and some slow control stair walking, keeping in mind you need your knees stacked over your ankle as you step BUt more importantly making sure you just dont go in and start full lunging.
The lunge, just think of as an exaggerated step, which requires and BUILDS not only strength, but balance and general coordination. Start with something like quarter lunges, holding onto a railing, keeping your upper body tall. Then you can progress into lower and lower, making sure you are "stacking" the knee over the ankle.

The other functional basic I would suggest is a squat or a slight knee bend to begin then progressing. Here is a picture of a DEEP squat
but for you, actually beginning to assume that position using that picture as the reference. Obviously don't go that far down, use maybe only a 1/4 or 1/2 movement - the picture is the reference of the chest up, knee stacked over ankle, hips back, back flat that is the "strong position" to teach to keep everything safe. Because you have a low back issue, you can modify this on a wall if needed. Put the feet about a half step in front, and slide up the wall as a modifier.

The finer pointers of these are making sure your hips are back and your chest is tall. The easiest way to teach this is to actually tell people to pretend there is a chair behind them and they need to sit in it, but not actually tell them where. The modification for these would be something like actually sitting in the chair, and doing "get-ups" ie. standing from the seated position to teach proper weight distribution on the heels, with the chest tall and the head up - NOT bending at the waist straightening the legs and reversing the waist bend.

Leg pressing is great as well, you can modify it if needed to do one leg. Just make sure that your knee tracks OVER your feet and that the knee stays stacked over the ankle - think of right angles.

I would definitely also work that ADDuction movement as well, focusing on smooth and controlled, QUALITY repetitions, making sure you realize you may be sore each time and that a big stretch may cause a little more soreness(its just tension under length)

Again Leslie for that leg extension I think doing isometric contractions(we call them "quad sets") of the knee when its in or near terminal extension. Working that terminal extension because when the quad KNOWS to fire in that position of extension before the replacement, actually getting it back and getting that terminal extension(Priority for TKR) you will already be a step ahead. So for these lying or seated on the floor, bed, table whatever you have. Leg straight out in front with a small towel underneath the back of the knee. Contract the quad, trying to press the back of the knee into the towel to get it into full terminal extension, hold for 10 seconds, then release the contraction. You can do these for sets of 10 sec hold, release for 2ish. The quads will get tired and "pumped" once you learn to activate them more.

A lot of information here: take it in and let me know what you think.
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So I have some more considerations if you are up for it Leslie.

Balance and stability, in ANY population is a "use it or lose it" type of skill.

ALSO remember that muscle activation is often hindered and shut down in periods of injury where there is lots of swelling or pain limited factors.

We know that a 10 horsepower body, when subjected to a 12 horsepower load, will eventually become a 12 horsepower body - the beauty of human performance.

So with this, its pretty safe to say most people walk on flat surfaces, with supportive shoes, using 2 feet and generally live in a stable(as far as footing is concerned) world.

For you because of your age and the fact you are having your TKRs its important to train balance NOW so that everything is easier as life continues for your and more importantly so that when you are post surgical, proprioceptive awareness is there and so that it is easier for you with your therapy once you start your functional transition(the best part :) ).

I personally have such limited time to train my own self that I have resigned to doing all my daily tasks on single foot, showering with eyes closed single leg all the stuff that I would do in a clinic or a gym, just modded for the house.

With this I would start working on balance, even the simple things like standing at the sink washing your hands on 1 foot, or doing dishes with 1 foot. Simple things where you stand with 2 feet, just lightly lift 1 off the ground.

REMEMBER balance is also affected by your vision; we use visual cue as a way to stabilize ourselves, so anytime your eyes are closed, balance is tremendously affected until is trained and upregulated.

What you will find is that your clinicians, once you get good at functional basics will be putting you into situations for you to train stability - soft foam pads to stand on, playing catch with 1 leg, using shoeless standing - eventually progressing you into a situation of being able to deal with many things instable. ***And if they don't...THEY SHOULD.*** Balance and stability training is a huge part for older populations and HUGE for anyone with an injury of any age. Making sure your body knows where it is in space and being able to react is imperative to relative performance.

The other thing I would do, is figure out who your therapist is going to be and make sure you have a GOOD gut feeling about him/her. Ask the clinician questions about how they progress patients with TKRs and make sure you are confident -ALL THERAPISTS ARE NOT CREATED EQUAL. Also, I would get a list of the exercises they will be progressing you with once you are post surgical, you can get a head start on that coordination and conditioning.

And for whatever it's worth to you Leslie, I worked with a 65 yr old avid runner who had a DOUBLE TKR and we actually had to slow him down during his rehab. He progressed so well because he wanted it so bad. Needless to say hes back to running and strong as an OX.

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