Leg extensions wreck the knees? What the science says
Vložit
- čas přidán 12. 07. 2024
- For more free fitness tips, check out my free email course: mennohenselmans.com/subscribe/
Chapters:
00:00 Introduction
00:15 Suboptimal for vastus medialis?
00:48 Too much ACL stress?
03:35 Conclusion
Reference:
journals.physiology.org/doi/f...
pubmed.ncbi.nlm.nih.gov/11588...
www.jospt.org/doi/10.2519/jos...
journals.sagepub.com/doi/abs/...
www.sciencedirect.com/science...
www.sciencedirect.com/science...
www.sciencedirect.com/science...
doi.org/10.4085/1062-6050-43....
bjsm.bmj.com/content/35/1/60....
Anatomy animation from @CompleteAnatomyElsevier
#mennohenselmans #legextension #legday #personaltrainer #exercisescience #trainingtips #quadriceps - Věda a technologie
🎯 Key Takeaways for quick navigation:
00:00 🤔 *Leg extensions are often considered unsafe for knees, but this view is challenged by scientific evidence.*
00:29 ✅ *Leg extensions activate the VMO (vastus medialis oblique) similarly to leg presses and squats, debunking the myth of causing imbalances in quad muscles.*
00:58 🏋️♀️ *Both open (like leg extensions) and closed (like squats) kinetic chain exercises are equally rehabilitative post-ACL reconstruction.*
01:27 🔄 *Different types of knee stress are exerted by leg extensions and squats, suggesting a balanced approach in workouts.*
01:57 📊 *A 2014 systematic review recommends including both open and closed kinetic chain exercises in ACL rehabilitation.*
02:28 🛑 *ACL joint strain from leg extensions is relatively low, and ACL injuries are rare in gym settings compared to athletic activities.*
02:58 🤕 *Patellar tendinopathy is a more common gym injury, with leg extensions proving effective in rehabilitation.*
03:29 🚫 *The concept of leg extensions being inherently bad for the knees is debunked as a myth.*
03:58 💡 *If leg extensions cause knee pain, modifying the exercise (like using high reps or occlusion wraps) is advised.*
04:28 🏋️♂️ *High repetition leg extensions with light weights and occlusion wraps can effectively stimulate quads while being easy on the knees.*
Made with HARPA AI
I did leg extensions exclusively during PCL rehab earlier last year. I also saw the 2019 study early in the process
Great content as always Menno keep it rolling
Makes total sense. Thanks for the video.
Great video. Thanks! 🙏
Brilliant content worthy of many more subscribers, wish you all the best Meno. I have patella tendinopathy right now and trying to work it out, currently doing high rep drop sets on LE but may try occlusion wraps also.
@Dan_the_Cobbler
I had someth8ng like that a very long time ago, but not now at age 75.
I think I cured it partly by a better Squats technique (i call it Max Aita style. Straigt down, straight up. Let your knees go forward!), and perhaps more importantly by supplements.
This is my supplements aimed at skin, joints, tendons, facia and bones:
Magnesium (up to 420 mg for men. But not so much that it upsets the intestines. Food is better, of course, but rather deficient nowadays.)
Vitamin D and K2 (5000 IU resp 200 ug of MK7)
Collagen 12 -- 15 g and some vitamin C
Boron 3 .. 6 mg
Glucosamine should perhaps also be in that list.
But remember, joint can take up to 4 years to heal!
Great content
I do get knee pain when adding extensions to my routine, but I haven't tried them with light weights high repetitions, good advice!
All my joints are good except for my knees-- they've been wonky for 30 years. I notice a BIG difference doing one leg at a time, probably because I can do less than half the weight with one leg than I can with two. So basically, it's just another way to reduce the weight without reducing effort, at least for me. Might be worth a try.
Physiotherapist here - most of the times, movements are not the problem getting pain. It is most likely the load management.
High reps made a huge difference for me as well as intensity techniques . Adding leg extensions and/or sissy squats back into my routine did more to help my knees than years of listening to the people who said to just squat and leg press
BFR as you mentioned is also tremendous, also great for anyone who has trouble feeling a stimulus from leg curls
Love that Dutsscchh accent, Menno! 😂
Coming from Fresh and Fit
Just subscribed
Great video
I replaced squatting with leg extensions and leg curls, and it has helped my back and knees enormously.
I avoided these since 2003 due to these myths, I crushed my L5S1 and can no longer squat, so I will start on these. Thanks!
Could you please do a video on grip training/forearm hypertrophy or could you tell me where I could find quality research about it.
Light leg extensions help my knees I think. BFR is perfect for them too.
Seconded on BFR, absolutely incredible tool
Hey. Nice video, thank you! I have another question for you: ist IT possible for the body to redistribute muscle protein from one muscle to another muscle? For instance, If you are Just training upper Body while neglecting your lower body entirely and not eating enough protein, too. Does the body then redistribute (if all the other protein demands for the immune system and so on are met) protein from the leg muscles to the upper body?
The body can catabolize one muscle to make another grow, yes. That's normally not desirable though.
Great Video! Do you find that leg extensions or sissy squats tend to be easier on the knees?
Leg extensions for most people.
Thank you!@@menno.henselmans
Good day. What does science says about strengthening of joints and ligaments in the knee? I have seen that for some people with knee problem reverse walking on the treadmill works very good but had not found any good scientific evidence for this.
It works. Progressive strengthening and overloading is key, not so much which type of exact exercise you do.
Even if leg extensions were stressful on the knees, just wrap a BFR cuff around your thigh and go super-light
Note to self, watch video before commenting 🤦♂
It's alright, chief. We forgive you. 🦵🏻😤
I just get some light quad tendonitis from time to time due to overuse, but I do the entire stack for medium reps. Squats usually get rid of this tendonitis. 30rm sets I can't do due to cardio limitations. Those are worse than higher rep squats for me and the pump becomes unbearable.
Thank you sir. As a powerlifter, I have been considering occlusion leg extensions - do you think this will have ANY carryover to 1RM strength?
Short-term, no, but long-term via adding muscle mass, definitely.
If anecdotal evidence is anything to go by, then it is a definite no! I think the danger to the knees occur if there is any lateral or medial movement, I can’t see how that can happen on a leg extension.
depends on the machine, there are some that put the pad not on the thigh but at the knee. don't know if it is more dangerous than the thigh ones, but it feels more uncomfortable
They are recommended by my Orthopedic Doctor .
I’ve trained for 60 years, always have done leg extensions, 4 years ago I had TKR and started extensions 3 months after. I just keep the weight down and lots of reps , no problems 🤔
I feel the opposite not on the knees but any overhead tricep extension wrecks my elbow.
Maybe a special on knees how to strengthen the cartlidge for most man above 50?
Get more glycine in your diet, that's the short version. Works at any age
Any comment on the reverse Nordic extensions, The bodyweight equivalent?
Good exercise. Not a crowd favorite though and you have to ease into them if you have sensitive knees.
This notion about lifting heavy squats and deadlifts needs to end its a sure road to injuries. I injured my back at 29 and started powerlifting again at 47 and reinjured myself.
I am now training at home, i have a multi station i do dumbbells squats, goblet squats and compliment with leg extension 4 sets of 20 reps my legs look amazing i am also 51.
I had an acl graft done many years ago, and I can feel leg extensions pulling hard on the graft, while squats do nothing. I'm not saying leg extensions could actually cause injury, but they definitely put unusual forces on the knee.
Nice!
I don’t do leg extensions myself. A long time ago I did them with very little results. Most likely, I didn't go to that painful failure? Wh8ch I now think is necessary with this specific exercise!
I do Sissy Squats, though. In my opinion they are almost the same. But the load curve is different. They train the quad muscles when more lengthened. Which should be interesting for those following the current trend!
I do squats, Romaian/Stiff legs deadlifts. Then sitting leg curls supersetted with Sissu Squats.
At age 75 my knees are fine. But I admit to supplementing for bone and joint health.
I actually regard Sissy Squats as a knee and patellar training, and not just qouads training.
In my youth, when 40 or so, I had some knee problem with what's called "movie goers knee". That's long gone now.
Training and supplements suits me!
leg extension with heavy weights do not fit for me but light weights with many reps feels ok
I bought a leg extension machine months ago and I train my quads very hard twice or 3 times a week and my knees feel amazing. I’ve recently felt younger and much more athletic. I can fall into my knees like I weigh 80 lbs, I can leap back onto my feet like I weigh as much as a feather. Just today I was standing on my truck bed and leaped off onto the ground athletically like a 16 year old and I’m 42. Leg extension is an amazing exercise that will definitely give you youthful leg bounce if you build strength up slowly and safely before you start pounding the big weights. I started off with just 1 45 lb plate the first week and slowly moved up, now I use 3 45’s and a 10 for 20 reps
Should leg extensions be avoided by someone with a total knee replacement?
I actually do more leg extensions coz it dosnt cause knee pain unlike hacks and squats
The studies you mentioned only showed knee extensions to be okay for short term rehabilitation after ACL/patellar injury/tendonitis. That's not the same as long term use at higher forces for building muscle and strength. So you cannot draw conclusions from this research about anything besides rehabilitation.
I'd keep knee extensions to once a week and only use lower load/higher reps, due to its open-kinetic-chain nature, force curve with full loading at full extension, high ACL and patellar strain, and lack of end range of motion where the knee angle is fully closed.
PS The study at 1:13 also found that increasing squat load did not further increase ACL strain, whereas increased load in knee extensions did increase ACL strain.
Any truth in the idea leg extensions are bad because the quads are almost bigger / stronger than hams ?
weird sound effect
Leg extensions wrecked my knees, never again. Ymmv