Why I Hate the Prone Knee Hang Stretch and What You Should Use Instead

Restoring full knee extension can be difficult in some patients (ACL-R, TKA, etc) and there are times when a low-load long duration stretch is called for - obviously in addition to all the other manual techniques and self repeated knee extensions. The most common LLLD knee extension stretch seems to be the prone knee hang. Even though it's the most common, I've never been a fan of it and I don't use it on my patients.

Why I Don't Like the Prone Knee Hang Stretch

By putting someone prone for an extended period of time it can increase the patient's anxiety level because they can't see what's going on around them. And I'm not talking freak out anxiety level, rather an inability to completely relax which is exactly what you are striving for to get the best stretch
It's easy for patients to compensate by letting their hips rise/shift and make the stretch not as effective. So in order to prevent this you have to strap their hips down to the table....thereby further increasing anxiety and not providing the optimal environment for the patient to fully relax
It's just not a comfortable position to be in - with your knees hanging off the table, your other leg propped up on a chair (if you actually even do that). Again, not allowing optimal relaxation to occur.
In order to make it a more intense stretch, you have to add weight all the way down by the ankle (long lever arm). A person's natural reaction to this added weight is to contract their hamstrings, thereby negating the purpose of the stretch in the first place.
It takes a good amount of your time to set the patient up correctly - valuable time that could be spent doing other more effective things.
The odds that a patient will be able to duplicate this stretch effectively on their own is very low. It takes a lot to set this stretch up, can only be done in certain areas (i.e. bed), and you can't really get anything else done when you're doing it. All in all, compliance with this has to be very low and I think it's easy to see why.

The Easier To Set-Up, More Comfortable, and More Effective Alternative

The way I use a low-load long duration stretch to improve knee extension is with the "Knee Terminator" - a device I designed myself because there were no other good options out there. Below is a picture of it in use (I use an ankle weight or standard olympic weight plate depending on the mood I'm in):

Out of all the options I've tried over the years (prone knee hang, hanging ankle weights from the knee, strapping the knee to the table, etc), my patients said the Knee Terminator was easily the most comfortable method and many have used it on their own at home - when was the last time one of your patients said they did a prone knee hang stretch at home!?

The Knee Terminator requires the least amount of weight to make it an effective stretch because the weight sits directly under the knee joint. The less weight needed, the more comfortable it will be for your patients...while still being effective.

And the best part about the Knee Terminator is it takes less than a minute to set up - saving you valuable time in your busy day!

How To Set It Up

Have your patient is sit in a chair with their foot on a stool/chair/etc. at the same level as the chair they are sitting in.
DO NOT let their heel rest on the stool because it will force them into dorsiflexion which will tension the gastrocs and limit the amount of knee extension they will get. You should put a half-foam roll (or rolled up towel) under their achilles - this allows their ankle to plantarflex which takes any tension out of the gastrocs. Tip - Even after you instruct patients to let their foot relax, most of them will slowly gravitate back towards a dorsiflexed position, so check on them every few minutes.
Then just put the Knee Terminator on and add the desired weight and you're done!
Typically, I start off with 5 lbs for 6-8 minutes. And as they can tolerate more, I increase the weight and/or time - I can't recall ever going over 10 lbs or 10 minutes and it still gives great results.

Why the Knee Terminator Is the Best Option Out There

Easier for the patient to relax (HS/gastroc muscles and overall) making it more effective
More effective because the weight is directly below the knee (so not as much weight is needed)
Easier for the patient to set up on their own at home (and actually be performed correctly)
Patients can do other things while in this set-up (read, watch TV, interact with others, talk to their therapist/other patients, etc.) - making it more likely to be performed
Compliance is a lot higher due to all the above reasons
A steal ($39.99) compared to other much more expensive apparatuses out there that cost over a $1000.
Patients have flat-out told me this set-up is better than anything else I've tried

Keeping it Eclectic...

Why I Hate the Prone Knee Hang Stretch and What You Should Use Instead