Resistance training is used to develop muscular strength and hypertrophy. Large muscle forces, in relation to the muscle’s maximum force-generating ability, are required to elicit these adaptations. Previous biomechanical analyses of multi-joint resistance exercises provide estimates of muscle force but not relativemusculareffort (RME). The purpose of this investigation was to determine the RME during the squat exercise. Specifically, the effects of barbellload and squatdepth on hip extensor, knee extensor, and ankle plantar flexor RME were examined. Ten strength-trained women performed squats (50-90% 1 repetition maximum) in a motion analysis laboratory to determine hip extensor, knee extensor, and ankle plantar flexor net joint moment (NJM). Maximum isometric strength in relation to joint angle for these muscle groups was also determined. Relativemusculareffect was determined as the ratio of NJM to maximum voluntary torque matched for joint angle. Barbellload and squatdepth had significant interaction effects on hip extensor, knee extensor, and ankle plantar flexor RME (p < 0.05). Knee extensor RME increased with greater squatdepth but not barbellload, whereas the opposite was found for the ankle plantar flexors. Both greater squatdepth and barbellload increased hip extensor RME. These data suggest that training for the knee extensors can be performed with low relative intensities but require a deep squatdepth. Heavier barbell loads are required to train the hip extensors and ankle plantar flexors. In designing resistance training programs with multi-joint exercises, how external factors influence RME of different muscle groups should be considered to meet training objectives.
Interesting new study. The full text can be checked out here in the JSCR if you are a member or if you’d like to purchase it.
“Concluded that squat depth needs to be greater than 105 degrees to maximize activation of the knee extensors. Conflicts with other research showing quadriceps activity peaks at around 80-90 degrees.” -Brad Schoenfeld
What’s the correct depth for squatting? Is it full depth performed ass to grass (ATG) or is it parallel?
As with most things fitness related what you do depends completely upon your goals. You need to have a general idea for what direction you want to go in fitness wise before you figure out what kind of squat is best for you.
Let me get one thing out there straight off the bat though.. partial reps will not suffice. What I mean by partial rep is what you commonly hear as half or quarter squats. Sure, at first you may lack the mobility necessary to have a better range of motion for squatting and that is 100% okay when starting out. The big picture to take away is that you don’t make partial rep squatting a mainstay in your lifting arsenal.
Now, some of you that are a little more versed in fitness and weightlifting have heard a lot of talk about ATG (Ass to Grass) squats and parallel I’m sure. First, I want to come clean and say that I, unfortunately, have been someone that played a bit of an elitist role early in my lifting days of saying that if squats are not performed at full depth (ATG) then they don’t count. I couldn’t have been more wrong.
I’m getting a little ahead of myself here. Today we’re just going to set up the examples of the differences between the two depths, ATG and parallel, so that you may have a visual representation moving forward.
Notice the full depth hit at the bottom of the squat. This person couldn’t get any deeper without magically contorting their glutes completely under their pelvis. Typically an ATG depth squat is performed with an Olympic style high bar placement on the upper traps, more upright torso, narrower stance and closer grip.
Take note of the hip crease in relation to where the quad lies and knee is. Most often a powerlifting style parallel squat is performed with a low bar placement on the rear deltoids, angled torso, moderate to wide stance and a wider grip than that of the Olympic squat. Also, in relation to an ATG squat notice that the glutes are not in contact with the back of the legs.
How can you tell when you’ve hit parallel? Well, it can be very tricky at first. You’ll often think you have when you haven’t because there’s a mental barrier right around that parallel mark. The best advice I can give you is to squat to your optimal depth based on your range of motion and slowly progress in adding weight to adhere to that full range of motion for depth.
Another great tool is using an anal retentive spotter. Finding that parallel mark in squatting can be where a very fickle and experienced spotter can really come in handy. The key is to watch for the hip crease not for the hamstrings. Many people make the mistake of thinking a parallel squat is when the hamstrings are at a 90º angle to the rest of the leg, but that’s not the case. Here’s an example:
True parallel is a line connecting the top of the knee and the crease of the hip, parallel to the floor.
Also, just for your reference here is an example of a squat that is at the above parallel position.
Obviously we have some major differences in depth and style for squatting, but which squat depth is right? Is it parallel or full depth? Both of them are are right. It just completely depends on your goals.
You’ll definitely still be working your muscles even if the depth is above parallel, but just not to the extent that you will once you’ve hit and gone beyond the parallel plane. I’ll speak more on that in the second part to this series. The biggest reason to make sure to hit parallel, aside from getting a good amount of muscle activation, is going to be for purposes of competition of sport such as powerlifting.
Now hopefully you understand the differences between the depths of squat. Stay tuned for Part Two of this series where I will dive into detail of the scientific benefits to each depth of squat alongside the reasons both will be effective or ineffective based on your goals.
I just don’t understand why people think it’s okay to do partial reps of anything, much less in squatting. Muscular development or strength is achieved by working muscles through a full range of motion. Squatting, benching, or curling through half of the ROM only trains the musculature through that given ROM and typically subjects it to injurious forces. For example, a half squat will not utilize the adductors, hamstrings, gluteals, or external rotators and as a result place excessive stress on the anterior aspect of the knee. This is why ignorant people claim that squats are bad for the knees. And why would someone want half a muscle?
Ego lifting is such a joke. Aside from the “let’s see how many plates I can put on the bar”, it isn’t quantifiable whatsoever. There’s no way to determine if one rep is comparable to another.
AbstractIt is unclear if increases in one repetition maximum (1-RM) in quarter squats result in higher gains compared to full depth squats in isometric force production and vertical jump performance. The aim of the research projects was to compare the effects of different squat variants on the development of 1-RM and their transfer effects to Countermovement (CMJ) and Squat Jump (SJ) height, maximal voluntary contraction (MVC) and maximal rate of force development (MRFD). Twenty-three women and 36 men (mean age: 24.11±2.88) were parallelized into three groups based on their CMJ height: deep front squats (FSQ, n=20), deep back squats (BSQ, n=20) and quarter back squats (BSQ¼, n=19). In addition a control group (C, n=16) existed (mean age: 24.38±0.50). Experimental groups trained 2 d·wk for 10 weeks following a strength-power periodization, which produced significant (p≤0.05) gains of the specific squat 1-RM. FSQ and BSQ attained significant (p≤0.05) elevations in SJ and CMJ without any interaction effects between both groups (p≥0.05). BSQ¼ and C did not reveal any significant changes of SJ and CMJ. FSQ and BSQ had significantly higher SJ scores over C (p≤0.05). BSQ did not feature any significant group difference to BSQ¼ (p=0.116) in SJ, whereas FSQ showed a trend towards higher SJ heights over BSQ¼ (p=0.052). FSQ and BSQ presented significantly (p≤0.05) higher CMJ heights over BSQ¼ and C. Post-test in MVC and MRFD demonstrated no significant changes for BSQ. Significant declines in MRFD for FSQ in the right leg (p≤0.05) without any interaction effects for MVC and MRFD between both FSQ and BSQ were found. Training of BSQ¼ resulted in significantly (p≤0.05) lower RFD and MVC values in contrast to FSQ and BSQ. Quarter squat training elicited significant (p≤0.05) transfer losses into the isometric maximal and explosive strength behavior. Our findings therefor contest the concept of superior angle specific transfer effects. Deep front and back squats guarantee performance-enhancing transfer effects of dynamic maximal strength to dynamic speed-strength capacity of hip and knee extensors compared to quarter squats.
tl;dr - Form > weight. Squatting deep increases explosiveness and vertical jump ability. Get low with full range of motion for best results.