Again, your concern with the length-tension relationship ignores that the leg is being accelerated to the ground at much greater ranges of motion and you’re only look at what’s happening once the foot is on the ground.
The angular momentum about the hip is slowed before ground contact, therefore the foot, shank, and leg are being decelerated before ground contact. Speed here would actually inhibit leg stiffness during ground contact as rapidly occurring changes in muscle-tendon lengths cannot produce as much force as one’s near resting states. My point about length-tension relationship remains valid from this point of view.
This article discusses stress relating only to joint moments at the knee and not the entire system and it also stresses in its conclusion limiting terminal joint flexion (ie less of it, albeit the article is geared towards clinicians and not S&C;work).
If your article is referencing peak posterior force data, you might want to put that reference on display as well. I would certainly agree with loads of the same mass that peak posterior forces would be higher the deeper the squat, but I am not discussing the external loads of the same mass am I?
Please be critical of what of you read in research journals before you post about it and pay attention to the audience and what it states. Also, be mindful I am relating stress to external load and not stress at joint moments as that is an entirely different subject and thread. Also, please don’t take out of context my posts and if you are going to be critical with them as least relate them to my points of reference and not one of a different point of reference.
Well, I was not only replying to your comment I was posting studies about squatting in relation to the original post. The article discusses stresses at knee joint, but it is stress nonetheless. I’m aware that you are relating stress to external load, but you are failing to take into account internal work done (i.e. the potential and kinetic energy permutations within body segments and work done by or on muscles). So you could relate that to the aforementioned study and conclude that one is completing more work by completing a greater ROM in full squat vs. 1/4 squat.
Here is that other study:
Takeo Nagura, Chris O. Dyrby, Eugene J. Alexander, Thomas P. Andriacchi *
Division of Biomechanical Engineering, Department of Mechanical Engineering, Stanford University, Durand Building, 227 Stanford, CA 94305-3030, USA
Again, your concern with the length-tension relationship ignores that the leg is being accelerated to the ground at much greater ranges of motion and you’re only look at what’s happening once the foot is on the ground.
The angular momentum about the hip is slowed before ground contact, therefore the foot, shank, and leg are being decelerated before ground contact. Speed here would actually inhibit leg stiffness during ground contact as rapidly occurring changes in muscle-tendon lengths cannot produce as much force as one’s near resting states. My point about length-tension relationship remains valid from this point of view.
Hi dbandre what is your background and experience in the S&C;field?
So you could relate that to the aforementioned study and conclude that one is completing more work by completing a greater ROM in full squat vs. 1/4 squat.
Did I not previously state that it’s more likely to produce more work with a greater ROM in a previous post??? Also, is it really necessary to do more work?
A different matter altogether is each of those articles you posted support not going with full ROM in squats because of stress on the knee joint. If you wish to supplement an argument it’s typically not best to use studies were the conclusion validates the person you are trying to contradict. Both suggest never going beyond 90-135 degrees which was my point with 1/2 squats and never having to go beyond parallel which is typically slightly less than 135 degrees.
Again, your concern with the length-tension relationship ignores that the leg is being accelerated to the ground at much greater ranges of motion and you’re only look at what’s happening once the foot is on the ground.
The angular momentum about the hip is slowed before ground contact, therefore the foot, shank, and leg are being decelerated before ground contact. Speed here would actually inhibit leg stiffness during ground contact as rapidly occurring changes in muscle-tendon lengths cannot produce as much force as one’s near resting states. My point about length-tension relationship remains valid from this point of view.
Hi dbandre what is your background and experience in the S&C;field?
I have 1249 posts on this board, while here I learned a lot and I become a better coach, so I won’t post a CV, but I do have a physical education degree and graduate work in biomechanics and motor learning as part of a Masters program that hasn’t been completed and is on hold right now as well as graduate work in endocrinology and neurobiology courses. In terms of experience in actually work, I am more of a coach, but I control S&C;work of my athletes. That work has produced 26 State Meet event qualifiers in track and field in 4 years, 4 national JO qualifiers in AAU/USATF in 5 tries, and 1 athlete on the preliminary list for the 2009 Youth World Championships. It also produced 7 new school records at a HS with pretty decent records for a small school. However, these things all mean little to myself as a coach, because I feel the most important achievements as a coach have been the doubling and tripling the participation numbers of athletes within the school I last worked and getting more kids interested in summer track and field programs.
Not always, but more work=more stress=increased endocrine response
A different matter altogether is each of those articles you posted support not going with full ROM in squats because of stress on the knee joint. If you wish to supplement an argument it’s typically not best to use studies were the conclusion validates the person you are trying to contradict. Both suggest never going beyond 90-135 degrees which was my point with 1/2 squats and never having to go beyond parallel which is typically slightly less than 135 degrees.
Well the reason they do not advocate going deeper is because they both concern individuals who were injured. I was pointing out the greater statistics from the deeper the squat in those studies. 1/2 squats are 90 degrees, 3/4 squat is closer to 135 degrees.
You bring up valid points, but increased appetite probably has more to do with energy output and work than anything (I would say full ROM squats probably do more work).
Appetite is largely regulated by endocrine (hormonal) function. There’s plenty of research that supports this. I’m not aware of anything that says the same about work. By the way, I’m not disagreeing that more work is done during full squats. This is actually undeniable. I’m just saying there’s not much justification that it’s a valid reason for dismissing my point that full squats likely have a bigger affect on endocrine output than partials. Also, appetite was only one example I gave…you didn’t address my and many others observations that full depth squats tend to promote increased leanness.
However, the body makes no distinction between the type or location of stress when related to endocrine response. You are right that stress doesn’t equal power or strength, but I wasn’t relating stress to power or strength only to mass upon the shoulders, where that stress is distributed depends completely on the joint moments.
I actually thought you were talking about training stress…not stress in a mechanical sense. I actually think the former is more relevant to the discussion. In any case, you’re likely correct in saying that the body doesn’t distinguish between the type or location of mechanical stress when related to endocrine response. With training stress (somewhat hard to quantify) this is probably not true.
And since I now know you’re speaking of mechanical stress and not training stress, why would we even really be concerned? Especially if we’re looking at it as a benefit?
Yes, as you go deeper the gluteals come into play more and changes in joint moments point this out, but you cannot say a specific muscle is firing hotter with sEMG, only the area of location of the sEMG is hotter, but not the why. Several things affect the values obtained by an sEMG electrode, one is location, two is the muscles in the vicinity which can produce crosstalk and signal cancellation, and three is the length of the electrode synapse.
You’re not telling me anything I don’t know. I’ve already acknowledged the limitations of sEMG. My previous point was that we are obviously limited by the tools of the trade but that we can still reasonably infer some conclusions based off the sEMG (which the research team and I have done). The question remains, what do you have to bring to the table that would refute the results of the previously mentioned study? What research method would alter the results in your favor? In my opinion, it’s not reasonable to complain about research results that are produced with technology that is limited when there isn’t an alternative technology that has lesser limitations.
The value of the information provided by an electrode is when a certain group of muscles is active, but information about joint moments after that activation is more important as it gives an idea of why the activation is occurring, either producing an acceleration or deceleration of the limb/body segment.
This is debatable. Why take only one when you have both? What research do you have to support your points even if we take just joint moments?
Your entire argument is based on glute-ham activation and mine is based length-tension relationship through a certain ROM.
Actually my argument was multi-factorial. Glute-ham activation was just one of the points I raised.
Certainly you cannot claim that a full squat with lighter loads of will produce a higher force output through the same segment of a 1/4 squat, which would be the last 1/4 of full squat.
Why can’t I? If you can’t understand how this is possible then you need to review Newton’s laws. You could apply more force and it would be manifested by greater acceleration of the athlete-plus-bar system.
How does force output or power equal stress? Load = stress.
No argument there. As I said, I misunderstood you and thought you were talking about training stress and not mechanical stress.
Doesn’t glute-ham activation occur when deadlifting and wouldn’t it be of more benefit to glute-ham activation than the squat?
I think DLs place a greater load on the hams than squats but not the glutes. As the research study cited above indicated, depth is the key to glute activation. The joint angles achieved in a DL simply don’t match those of a deep squat. Also, I tend to use OLs extensively and placing both DLs and OLs in the program would be a little redundant. Finally, the DL doesn’t have an elastic component to it in the same way that squatting does.
I do think you need both emg and joint data to make an educated opinion about what is going, but joint data alone is more valuable than emg data alone.
My athletes are lean with 1/2 and 1/4 squats, they do parallels in their routine often early in a mesocycle and sometimes revisited later for a brief period, usually after winter and spring break periods.
I believe if the athlete’s hip joint is low in a starting position for deadlifts, they must have gluteal activation. Hamstring activation alone probably wouldn’t be enough to move a slightly heavy bar, even back extensors and hamstrings would have a hard time producing the hip extension needed for a quality lift. I switched from a deadlift/squat on same day routine for my athletes and by chance happened to see better results at the time of transition from 1/2 to 1/4’s over the previous season. (i believe posted about this 2 years ago) In that time I was also taking a pretty good biomechanics course were we discussed the validity of specific range of motions to the length-tension relationship. That point cannot be refuted, it’s transference to specific range of motions between to unrelated activities no doubt has some serious issues to overcome and even trying to study it would be hard to control variables.
The endocrine responses to lifting make up a lot the remodeling of the muscle, if you create a greater stress there will always be more remodeling but also possibly longer recoveries. If your kids are sprinting, jumping, and throwing why create a larger stress instead of one that supplements the training. I think kids training 15-16 hours a week are getting more than an adequate endocrine response, especially when you consider they probably trained 8-10 hours per week or even less prior to working with me.
Just that you are doing a greater amount of physical work and more stress should lead to a greater endocrine response and greater metabolic changes within the body. However, I think it’s pushing the limits of the injury spectrum for a diminishing return gain. For an elite athlete pushing that envelope I think it is needed, but HS athletes who cannot already handle a greater workload because of previous training, fitness, and ability need to stay within their limits and build it.
As far as newton’s law goes the starting point of the 1/4 squat is at a point when the bar has already been accelerated during a full rom squat. at 45 degrees of knee flexion in a full rom squat, the angular acceleration about the knee is either decelerating, or is at or approaching zero acceleration, where as in a 1/4 squat it is just beginning acceleration. The force output at 45 degrees of flexion in the knee has to be higher in the 1/4 squat.
Which do you believe has a greater elastic component 1/2,1/4,full,3/4(parallel) or are they all similar. I believe the elastic component of the lift changes with greater elasticity elicited at the hip and ankle in 1/4 to almost exclusively at the knee in 3/4 and beyond.
Again, your concern with the length-tension relationship ignores that the leg is being accelerated to the ground at much greater ranges of motion and you’re only look at what’s happening once the foot is on the ground.
The angular momentum about the hip is slowed before ground contact, therefore the foot, shank, and leg are being decelerated before ground contact. Speed here would actually inhibit leg stiffness during ground contact as rapidly occurring changes in muscle-tendon lengths cannot produce as much force as one’s near resting states. My point about length-tension relationship remains valid from this point of view.
Hi dbandre what is your background and experience in the S&C;field?
I have 1249 posts on this board, while here I learned a lot and I become a better coach, so I won’t post a CV, but I do have a physical education degree and graduate work in biomechanics and motor learning as part of a Masters program that hasn’t been completed and is on hold right now as well as graduate work in endocrinology and neurobiology courses. In terms of experience in actually work, I am more of a coach, but I control S&C;work of my athletes. That work has produced 26 State Meet event qualifiers in track and field in 4 years, 4 national JO qualifiers in AAU/USATF in 5 tries, and 1 athlete on the preliminary list for the 2009 Youth World Championships. It also produced 7 new school records at a HS with pretty decent records for a small school. However, these things all mean little to myself as a coach, because I feel the most important achievements as a coach have been the doubling and tripling the participation numbers of athletes within the school I last worked and getting more kids interested in summer track and field programs.
Thats good. Are you familiar with Coach Mark Rippetoe’s work? He is someone who has 30 years of experience with barbell training. And he says squatting above parallel can hurt your hips and knees. He has authored couple of great books too.
Wow! Thanks for the info. guys. I thought this topic might be a little too simple to get much of a response. I was hoping for maybe an article or two with a few comments.
Mike,
After being on these forums for the last few years, I have to say that I always love it when people get you going on a good argument. Differing views bring out so much great info.
What would be the best way to allow my athletes to gauge where parallel is? I have two “safety squat” beepers from BFS, but I’m not sure if I like them and I will have a lot more than 2 athletes working out at one time. I thought I read somewhere that touching a 12” box works well. Would that be about right? I would like to have something to help them gauge how low to go, especially in the beginning. Plus, I won’t always be ablt to watch every workout or rep.
Wow! Thanks for the info. guys. I thought this topic might be a little too simple to get much of a response. I was hoping for maybe an article or two with a few comments.
Mike,
After being on these forums for the last few years, I have to say that I always love it when people get you going on a good argument. Differing views bring out so much great info.
What would be the best way to allow my athletes to gauge where parallel is? I have two “safety squat” beepers from BFS, but I’m not sure if I like them and I will have a lot more than 2 athletes working out at one time. I thought I read somewhere that touching a 12” box works well. Would that be about right? I would like to have something to help them gauge how low to go, especially in the beginning. Plus, I won’t always be ablt to watch every workout or rep.
I think ‘Starting Strength Barbell Training’ and ‘Practical Programming’ both books by coach Mark Rippetoe are among the best sources to learn the correct back squat and other big lifts. He also has a Q&A;at strengthmill.net
However, these things all mean little to myself as a coach, because I feel the most important achievements as a coach have been the doubling and tripling the participation numbers of athletes within the school I last worked and getting more kids interested in summer track and field programs.
Thats good. Are you familiar with Coach Mark Rippetoe’s work? He is someone who has 30 years of experience with barbell training. And he says squatting above parallel can hurt your hips and knees. He has authored couple of great books too.
Spur:
I have to say no, and most likely I probably won’t read it, because book’s aren’t subjected to same scientific or professional scrutiny and peer review as articles in scientific and professional journals. That doesn’t mean I won’t read or reference books ever, but their use to someone such as myself is they are 5 years behind research by the time they are published.
On a side note, I seriously doubt squats above parallel hurt knees and likely saves them as the research posted earlier points out and I have serious doubts my athletes lack hip mobility or flexibiliy with amounts of work we do that involve large ROM’s about the hip. That said, the only injuring in 5 coaching years related to training was a stress fracture of a foot, likely caused by running hallway corners indoors too fast during winter and sprinting hallways has been reduced to straight away acceleration sprints of 30m or less, because of that injury.
Novice:
Learning involves something other than mindlessly following what Mike, JJ, or Quik post as gospel. I consider Mike a great mentor, but I disagree with him on this issue and disagree less than most of you think. What I have learned just from this site alone was the amount of differing opinions and most of it I attribute to Mike and his colleagues. If you don’t have some constructive to say and in fact you can only say I won’t learn then you don’t grasp the full amount of knowledge available out there and someone must read, analyze, and form their own opinions on from the available sets of knowledge they had previously acquired. Even great researchers in biomechanics such as James Hay and Paavo Komi have made mistakes.
