PDA

View Full Version : front squats vs back squats- biomechanical differences



TPT
07-04-2009, 04:48 PM
this paper by gullet et al. (2009) showed some interesting info on the differences between the back and front squat that we should consider. ill be back to chat about them.




Gullett, JC, Tillman, MD, Gutierrez, GM, and Chow, JW. A biomechanical comparison of back and front squats in healthy trained individuals. J Strength Cond Res 23(1): 284-292, 2008-The strength and stability of the knee plays an integral role in athletics and activities of daily living. A better understanding of knee joint biomechanics while performing variations of the squat would be useful in rehabilitation and exercise prescription. We quantified and compared tibiofemoral joint kinetics as well as muscle activity while executing front and back squats. Because of the inherent change in the position of the center of mass of the bar between the front and back squat lifts, we hypothesized that the back squat would result in increased loads on the knee joint and that the front squat would result in increased knee extensor and decreased back extensor muscle activity. A crossover study design was used. To assess the net force and torque placed on the knee and muscle activation levels, a combination of video and force data, as well as surface electromyographic data, were collected from 15 healthy trained individuals. The back squat resulted in significantly higher compressive forces and knee extensor moments than the front squat. Shear forces at the knee were small in magnitude, posteriorly directed, and did not vary between the squat variations. Although bar position did not influence muscle activity, muscle activation during the ascending phase was significantly greater than during the descending phase. The front squat was as effective as the back squat in terms of overall muscle recruitment, with significantly less compressive forces and extensor moments. The results suggest that front squats may be advantageous compared with back squats for individuals with knee problems such as meniscus tears, and for long-term joint health.

(C) 2009 National Strength and Conditioning Association

Go to Full Text of this Article (http://forums.rxmuscle.com/nsca-jscr/Fulltext/2009/01000/A_Biomechanical_Comparison_of_Back_and_Front.41.as px)

TPT
07-04-2009, 07:33 PM
ok, a break from barbeque.

the experimenters studied knee kinetics and emg activity differences of healthy adults during front and back squats.

stat significant differences were found between knee compressive forces of front and back squats. so back squats had higher compressive forces and at about 95 degrees of knee flexion. so keep that in mind when having knee dysfunction and going too low during squats. stat significant knee extensor moment was evident with back squats having more. that makes sense if compressive forces were more for back squats.

strangely emg activity was lower during descent for both squats. no differences of muscle activity was found between squats as well. we'll have to examine the methodology because this is curious. anyway, it still make you think a bit when prescribing one squat over the other. a look closer at the emg data and semitendinosous had the greatest activation. hmmn...interesting for those looking to recruit medial hams. also, vmo was greatly activated- for those who care about developing medial quads.

anyway, this paper has some utility in reminding us to be friggin careful going too low. as well as being careful when having knee problems including acl/pcl impairments because of the compressive/shear forces. also, maybe bar position doesnt influence activation that much. eg. front squats and quad activation.

anyone have a preference over different squating?

GottaGetLean
07-04-2009, 07:35 PM
nice info!:beerbang:

Klaus Urine
07-04-2009, 08:45 PM
I find front squats really uncomfortable. Means I have to use much less weight, which I believe in turn will lead to poorer results.

TPT
07-05-2009, 01:24 PM
nice info!:beerbang:



thanks ggl.

B7emm
07-05-2009, 01:33 PM
i have less back pain from front squats. but i can not use as heavy weights. i prefer back squats but the pain is killer right now.

TPT
07-05-2009, 02:20 PM
I find front squats really uncomfortable. Means I have to use much less weight, which I believe in turn will lead to poorer results.



yeah, front squats can be uncomfortable with the load by your clavicles and maintaining your shoulders in a flexed isometric contraction. changing the position of the load might expose some our shoulder or chest weaknesses.

TPT
07-05-2009, 02:29 PM
i have less back pain from front squats. but i can not use as heavy weights. i prefer back squats but the pain is killer right now.



that is definantly something to consider. back pain could be a function of lesser loads in general or lesser compressive forces to the spine.

B7emm
07-06-2009, 10:42 PM
my quadratis on the left side is relay weak. i have been building my core back up it helps. i still have a bulge in my l4/l5. i feel the pain is from compression since my left foot will go numb. i dont have that with front squats.

TPT
07-07-2009, 12:31 AM
my quadratis on the left side is relay weak. i have been building my core back up it helps. i still have a bulge in my l4/l5. i feel the pain is from compression since my left foot will go numb. i dont have that with front squats.



be careful with all exercises that would increase compressive forces to your lumbar spine including back squats. most people will confirm l4 and l5 disc herniation with abnormal sensations around the medial ankle and above the third toe, respectively. as well as weak anterior tib (dorsiflexion), great toe extension, and glute medius (hip abduction). quads are innervated by l4 too.

be friggin careful.

BrownBear
07-07-2009, 12:46 AM
recently, like 2 weeks ago recently, i've decided to replace back squats with front squats. i didnt like them when i tried them periodically in the past cause the bar tends to roll forward on the arm causing my biceps to cramp however i tried them two weeks ago and have found if you really just commit to the form and place the majority of your weight on your heels you won't have this problem. No, you will not be able to use as much weight, however your lumbar and knees will thank you greatly

thfireguy
07-07-2009, 01:13 AM
I use both a front and a back squat. I rotate and vary my routine even though the front will be a lighter weight. It still gets great quad activation for me and if I want to go heavy with a front I can use the smith machine (not a big fan of this though) takes away some of the stability problems. Never had knee or spine problems even with heavy squats. BTW good info

B7emm
07-07-2009, 01:40 AM
be careful with all exercises that would increase compressive forces to your lumbar spine including back squats. most people will confirm l4 and l5 disc herniation with abnormal sensations around the medial ankle and above the third toe, respectively. as well as weak anterior tib (dorsiflexion), great toe extension, and glute medius (hip abduction). quads are innervated by l4 too.

be friggin careful.

i will thanks bro.

SoxFan11
07-07-2009, 02:32 AM
I have a herniated disk (C5/C6) and so I am not allowed to do back squats. I have substituted front squats and forgot how much I like them. I feel that they place a greater emphasis on the quads, with much less help from the glutes and hamstrings. I also find the front squat to be much easier to perform given my body's proportions (long torso, shorter legs.

G-Roy
07-07-2009, 11:22 AM
Front squats definately aggravate my knee issue much less than back squats. Most of the time, I cant keep the weight supported properly before my legs get tired.

TPT
07-07-2009, 12:35 PM
I use both a front and a back squat. I rotate and vary my routine even though the front will be a lighter weight. It still gets great quad activation for me and if I want to go heavy with a front I can use the smith machine (not a big fan of this though) takes away some of the stability problems. Never had knee or spine problems even with heavy squats. BTW good info


cool. thanks.

TPT
07-07-2009, 12:40 PM
I have a herniated disk (C5/C6) and so I am not allowed to do back squats. I have substituted front squats and forgot how much I like them. I feel that they place a greater emphasis on the quads, with much less help from the glutes and hamstrings. I also find the front squat to be much easier to perform given my body's proportions (long torso, shorter legs.



sorry to hear about your c5/c6 herniation. good thing that youre laying off back squats. conceptually, you could go light with the bar low on your upper traps but id still use extreme discretion based on your neural symptoms.

the greater emphasis on quads seems to common across many of us.

Frosty
07-07-2009, 01:35 PM
Hmm, some random thoughts.

Perhaps this is one reason why olympic lifters tend to not have to many knee injuries even though they almost wipe their ass on the platform in the bottom of the clean, since the front squat puts less stress on the knees than the back squat?

Going deep also requires very good hip flexibility. It's possible to hurt your lower back if you do not have good flexibility because things pull on the back weird. I've had this happen.

For me, I notice the crossed arm position forces you into better posture than the clean grip can allow. I had to switch when my arms got bigger and I have to say I feel the posture is better if you're just squatting. If you do olympic lifts of course then I think that is a good grip to use so you can be proficient in the olympic lifts.

Also for high rep work, I don't think front squats are good because the muscles in the upper back used to hold the weight in position fatigue faster, plus the compressive force on the rib cage makes breathing heavy very difficult. The proper form for front squats essentially almost chokes you...not good for a 20 rep breathing squat routine....lol

Poliquin seems to feel that front squats are superior for most athletes.

The pain across your clavicles, chest, and shoulders goes away after you numb your body to it. Hell when I first started high bar back squatting my shoulders and traps were killing me.

I definitely think healthy knees are a requirement to squat deep and heavy. Just like people with bad shoulders shouldn't do many pressing lifts because their shoulders aren't healthy. But for healthy knees, I'm a firm believer in going as deep as you can with good form.

I also think variety is a good thing. Back squats, front squats, wide and narrow stance for both, heels elevated or heels flat, high bar or low bar....it's all different stimulus to help keep gains going. I think changing up those things would be enough to keep progress going since the lower body needs less variety than upper body.

AlanH
07-07-2009, 05:26 PM
I find front squats really uncomfortable. Means I have to use much less weight, which I believe in turn will lead to poorer results.

very uncomfortable:beerbang: