Posted February 3, 2011

Q & A: Effective versus Full Range Of Motion

Hi Dean. I had right ACL surgery in June, 2010. With time I’ve been able to get my legs back to equal strength. Lately, I noticed pain in my right knee when working out. Should I stop all squatting, deadlifting, lunges and focus on quad activation for a while?

This was an email question I had following my post on Quad Activation Series, and to be honest, the answer is both yes and no, which pretty much blows your world off its’ axis.

How can it be two things at once??!?!! It doesn’t make sense!!!!! My mind is about to explode!!!

No, you should not stop doing leg exercises, simply because they are going to be important to reduce any muscle imbalances that may arise as a result of the surgery. When a joint is damaged, the first thing the body does is get the nerve to turn down the impulse going to the muscles that control the movement of that joint. This helps to reduce the amount of pressure exerted on a damaged body part by the muscular system and limits secondary damage done, however the downside is that now the joint isn’t as strong, and much less stable than before, which also predisposes it to injury. Kind of a double-edged sword.

However, yes, you should stop doing your leg exercises the way you have been doing them. I’ve had a lot of trainers shadow during some of my sessions, and I always get the same questions:

Dean, how do I get to be as cool and good-looking as you??

Dean, why are most of your clients working with less than ideal technique and less than full range of motion??

Well kids, I can’t help you with the first one, but the second one is a pretty easy one to explain. Imagine for a second that you just had shoulder surgery or are just recovering from an injury to your rotator cuff that has left it somewhat stiff and with limited mobility. Ideally, we would try to make that shoulder move through its full range of motion as much as possible. However, if we were to take it all the way into terminal extension and external rotation too soon, it would probably cause more damage it would help, and therefore the range of motion would have to be limited.

As an area of the body gets injured and begins to recover, the tissues become somewhat atrophied, stiff and brittle, and the body will lay down collagenous fibers as scar tissue to increase the strength of the area and prevent further damage. when we try to recover that range of motion, we’re working against the scar tissue, the atrophy, and the brittleness of the affected tissues, which could include muscles, tendons, ligaments, joint capsules, fascia, and circulatory organs plus nerve tissue. These tissues don’t stretch well at the best of time, so pushing the stretch may be damaging. Therefore, a full range of motion may be different from an effective range of motion.

Take for example one of my clients, who has severe joint degeneration of the knees:

ARVE Error: need id and provider

The joint has developed osteophytes, essentially small bony growths that have pushed the joint into its’ dysfunctional position and limited his mobility. He’s going to need a knee replacement in the future, regardless of what we do for exercise, simply because he has had structural alterations to the bones themselves. We can squat and deadlift and quad activate all we want, but it’s not a muscle problem, it’s bone.

To perform a  squat with Fred, he simply can’t go very deep into it because of the joint mechanics, so pushing him there would be possible, but very painful and less than beneficial for him.

With an ACL injury, it is going to be dependent on the type of graft used (allograph from a cadaver, bone-tendon-bone graft from the patellar tendon, or semitendinosus graft from the hamstring), as well as how tight the surgeon pulls the graft and how much laxity there is in the joint following surgery. Most surgeons will pull that sucker tighter than Adriana Lima’s pigtails.

If the graft is pulled even 0.1mm tighter than the original ACL, the knee mobility through flexion will be noticeably reduced and will affect the ability to regain total range of motion. The tradeoff is that the knee will be more stable and less likely to become reinjured, so the surgeon will always err on the side of caution.

When trying to complete rehab and perform squats, the knee won’t flex past a certain point due to mechanical blockages from swelling, muscle tension, joint capsule stiffness, and the length of the graft itself, so full range of motion in this knee would be much less than normal. The effective range of motion may even be less, as the further into terminal range the person goes, the greater the pressure on the supporting structures becomes, and the more likely that muscles will start de-activating in an attempt to save the joint. Reducing the range to more of a mini-squat or even half squat would be more effective, even though it would be less than full.

This effective range of motion reduces when we add axial loading to the knee, like in a barbell squat or deadlift variations. As the knee approaches its maximum sustainable range of motion, the external force will cause the muscles to contract harder, therefore increasing the risk of injury to the joint, and therefore making the nerve want to shut it down and force a compensation pattern to prevent injury. Should you load the joint? Yes, but you may not be able to take it to the full range of motion without pain or compensation, so using a shorter range of motion with loading will provide better results overall, especially when pairing with soft tissue work on foam rollers, as well as active mobilization for the muscles of the knee and hip.

ARVE Error: need id and provider

ARVE Error: need id and provider

So at the end of a long-winded answer, don’t stop doing what you’re doing, but make sure you aren’t forcing a range of motion that might be detrimental, and make sure you are working with the best technique possible for your knee mechanics.

 

 

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