Why shouldn't squats be done past a 90 degree angle?
- Thread starter Mariela
- Start date
Somewhere on this site she states that a true squat is going way down. I don't remember all the facts, and have never squatted that way. Most of her strength info is pretty good though.
http://www.stumptuous.com/weights.html
Andrea
http://www.stumptuous.com/weights.html
Andrea
naughtoj
Cathlete
I know about the danger with the knees but I have heard that doing squats all the way help with your range of motion and staving off arthritis. I don't like it though. I will trust Cathe. I cannot remember what Krista Smash says about this on her website, I will have to revisit it again...
Janice
Janice
Andrea,
The website you mentioned is that of Mistress Krista--I wouldn't advise anyone to follow her information. She makes unsupported statements via out-of-context quotes and does not have a background in any form of exercise science.
I had e-mailed her about the problems with full squats--they greatly increase compressive forces on the patellofemoral joint and place all four tibiofemoral ligaments in a slackened position, making the knee less stable. Of course, she disagreed.
Her contention is that squats past 90 degrees don't increase compressive forces in the knee--true enough, if one is speaking of the tibiofemoral joint, but what she fails to recognize is that forces on the patellofemoral joint increase tremendously due to the tightening of the quadriceps. Additionally, she does not take into consideration the lack of ligamentous stability at angles greater than 90 degrees.
She also concludes--erroneously--that the hamstrings are activated to a greater degree past 90 degrees of knee flexion, therefore increasing the protection of the ACL. This, too, is untrue, due to something known as passive insufficiency. Once the knee is flexed beyond 90 degrees, the amount of force the hamstring can exert on the knee is minimized.
Yes, theoretically the glutes are more highly recruited in deeper squats for two reasons--greater range of motion at the hip joint and the passive insufficiency of the hamstrings when the knee is flexed beyond 90 degrees, limiting its contribution to hip extension. But (no pun intended), the glutes can be maximally worked with less risk to the knees in ways other than full, buns-to-heels squats.
Do I think full squats are a no-no for everybody? No. As long as a person has no knee problems and has very vigilant spotters, full squats can be performed relatively safely. But, over time, they are very wearing on the patellar articular cartilage, put shear stresses on the meniscus, and, unless you are an athlete who needs this particular ability, probably present more in the way of risks than benefits.
Maribeth
The website you mentioned is that of Mistress Krista--I wouldn't advise anyone to follow her information. She makes unsupported statements via out-of-context quotes and does not have a background in any form of exercise science.
I had e-mailed her about the problems with full squats--they greatly increase compressive forces on the patellofemoral joint and place all four tibiofemoral ligaments in a slackened position, making the knee less stable. Of course, she disagreed.
Her contention is that squats past 90 degrees don't increase compressive forces in the knee--true enough, if one is speaking of the tibiofemoral joint, but what she fails to recognize is that forces on the patellofemoral joint increase tremendously due to the tightening of the quadriceps. Additionally, she does not take into consideration the lack of ligamentous stability at angles greater than 90 degrees.
She also concludes--erroneously--that the hamstrings are activated to a greater degree past 90 degrees of knee flexion, therefore increasing the protection of the ACL. This, too, is untrue, due to something known as passive insufficiency. Once the knee is flexed beyond 90 degrees, the amount of force the hamstring can exert on the knee is minimized.
Yes, theoretically the glutes are more highly recruited in deeper squats for two reasons--greater range of motion at the hip joint and the passive insufficiency of the hamstrings when the knee is flexed beyond 90 degrees, limiting its contribution to hip extension. But (no pun intended), the glutes can be maximally worked with less risk to the knees in ways other than full, buns-to-heels squats.
Do I think full squats are a no-no for everybody? No. As long as a person has no knee problems and has very vigilant spotters, full squats can be performed relatively safely. But, over time, they are very wearing on the patellar articular cartilage, put shear stresses on the meniscus, and, unless you are an athlete who needs this particular ability, probably present more in the way of risks than benefits.
Maribeth
Maribeth. Many thanks for the information. This answer my question.
I have a question in the open discussion forum that I would like you to answer if you don't mind. Here's the link:
http://64.225.138.194/dcforum/Open/4002.html
I have a question in the open discussion forum that I would like you to answer if you don't mind. Here's the link:
http://64.225.138.194/dcforum/Open/4002.html
RE: Maribeth, what is your feeling on this twist?
Hey Maribeth,
I've been dying to get your opinion on this. My own trainer, who I generally respect or I wouldn't keep paying him, routinely has his clients do full squats with light (3-10 lbs.) db's with the heels elevated on a 2x4. I was initially very resistant to this because I have had knee problems, but this has not aggravated them at all, and I do think that over time it has helped give a longer, leaner look to my somewhat bulky quads.
His contention is that elevating the heels changes the biomechanics and contact points within the knee joint and is safe as long as the client is already conditioned to squatting with good form and weight is kept light. What's your take on this?
FitnessRN
Hey Maribeth,
I've been dying to get your opinion on this. My own trainer, who I generally respect or I wouldn't keep paying him, routinely has his clients do full squats with light (3-10 lbs.) db's with the heels elevated on a 2x4. I was initially very resistant to this because I have had knee problems, but this has not aggravated them at all, and I do think that over time it has helped give a longer, leaner look to my somewhat bulky quads.
His contention is that elevating the heels changes the biomechanics and contact points within the knee joint and is safe as long as the client is already conditioned to squatting with good form and weight is kept light. What's your take on this?
FitnessRN
RE: Maribeth, what is your feeling on this twist?
Hey FitnessRN,
What elevating the heels in a squat will do is allow someone with tight calves to drop lower into the squat by slackening the soleus. Since as the squat progresses, the foot moves into a greater degree of dorsiflexion, a tight soleus will stop the tibia from moving forward over the foot, which at the knee, will equate to a lesser degree of flexion. By elevating the heels, the stretch on the soleus is lessened, and the degree of knee flexion can be increased.
Plantar flexion of the ankle in a closed chain position (such as elevating the heels for squatting) also tends to either pitch the pelvis forward, causing the person to have to lean the upper torso backward or will cause the person to have to start the squat in a position of more hip flexion, pushing the buttocks back and the upper torso forward--basically a reverse of the pelvis forward-trunk back position--in order to balance.
The first scenario puts waaay more compressive force on the patellofemoral joint and more shear force on the tibiofemoral joint. The latter actually can facilitate good form, and can decrease patellofemoral compressive and tibial anterior shear forces somewhat by slackening the rectus femoris across the hip (due to starting in a more hip flexed position), reducing the pull of the quads on the tibia and the compression of the quads on the patella.
Thing is, when you elevate the heels and squat deeper than 90 degrees, you have two factors that are problematic. The greater than 90 degree flexion is where the knee is most unstable ligamentous wise AND the heels elevated position is more unstable for the ankle. Combine these two factors with the fact that there is less surface area of the foot in contact with the ground, and you have instability x 3. And, the further past 90 degrees you go, the LESS the hamstrings and gastrocs contribute, meaning there is less dynamic resistance to anterior shear forces.
The big thing to remember here is that if you choose to do the deep squats, especially if you do them via heel elevation, you HAVE to be very, very stable in your exercise. Even a slight bobble at these depths can result in damage to articular cartilage, meniscus and/or ligaments due to the slackened ligaments and decreased muscular resistance to shear forces. And regardless of the somewhat lessened compressive forces of the quads on the patella due to the heel elevation, they are still much greater as you pass the 90 degree point.
Long answer to a quick question--sorry for the book!
Maribeth
Hey FitnessRN,
What elevating the heels in a squat will do is allow someone with tight calves to drop lower into the squat by slackening the soleus. Since as the squat progresses, the foot moves into a greater degree of dorsiflexion, a tight soleus will stop the tibia from moving forward over the foot, which at the knee, will equate to a lesser degree of flexion. By elevating the heels, the stretch on the soleus is lessened, and the degree of knee flexion can be increased.
Plantar flexion of the ankle in a closed chain position (such as elevating the heels for squatting) also tends to either pitch the pelvis forward, causing the person to have to lean the upper torso backward or will cause the person to have to start the squat in a position of more hip flexion, pushing the buttocks back and the upper torso forward--basically a reverse of the pelvis forward-trunk back position--in order to balance.
The first scenario puts waaay more compressive force on the patellofemoral joint and more shear force on the tibiofemoral joint. The latter actually can facilitate good form, and can decrease patellofemoral compressive and tibial anterior shear forces somewhat by slackening the rectus femoris across the hip (due to starting in a more hip flexed position), reducing the pull of the quads on the tibia and the compression of the quads on the patella.
Thing is, when you elevate the heels and squat deeper than 90 degrees, you have two factors that are problematic. The greater than 90 degree flexion is where the knee is most unstable ligamentous wise AND the heels elevated position is more unstable for the ankle. Combine these two factors with the fact that there is less surface area of the foot in contact with the ground, and you have instability x 3. And, the further past 90 degrees you go, the LESS the hamstrings and gastrocs contribute, meaning there is less dynamic resistance to anterior shear forces.
The big thing to remember here is that if you choose to do the deep squats, especially if you do them via heel elevation, you HAVE to be very, very stable in your exercise. Even a slight bobble at these depths can result in damage to articular cartilage, meniscus and/or ligaments due to the slackened ligaments and decreased muscular resistance to shear forces. And regardless of the somewhat lessened compressive forces of the quads on the patella due to the heel elevation, they are still much greater as you pass the 90 degree point.
Long answer to a quick question--sorry for the book!
Maribeth