Adarq.org
Performance Area => Article & Video Discussion => Topic started by: adarqui on June 02, 2009, 12:39:22 am
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Questions/Comments/Discuss.
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Questions/Comments/Discuss.
Wheres the link adarqui?.
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Link?
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dno, it's on RJ's site somewhere, i forget the url to his site lol....
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LMFAO. :uhhhfacepalm:
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All Aboard the A-Chain
Roger Nelsen
Louie Simmons once said something along the lines of, “A strong man is strong on the back of his body.” And whether it was intended to or not, it was these words, along with his training advice, that sparked off a wave in the S&C industry. Following in the steps of the famous Westside gym leader, people everywhere began to turn their focus away from their sweeping quads and redirect it towards the less mirror-friendly group of muscles commonly referred to as the posterior chain.
Consisting of the spinal erectors, glutes, and hamstrings, the muscles of the P-chain work to stabilize and generate force across the hip, and knee. Over the past few years, the words “posterior chain” have become all but synonymous with athletic speed and power thanks to Louie Simmons and those who have successfully adapted his methods to popular sports (such as trainer Joe Defranco). But in this torrent of box squats, glute-ham raises, reverse hypers, and good mornings, some people have lost sight of the P-chain's equally important, but much less glamorous counterpart, the anterior chain.
Positioned directly opposite of the posterior chain, the anterior chain consists of the abdominal muscles, the illiopsoas, and the rectus femoris. And where the posterior chain works to create spinal and hip extension, the anterior chain works to create spinal and hip flexion.
At first glance, spinal and hip flexion might not seem too important in most sports, but a closer look reveals the exact opposite, especially where sprinting speed is concerned. Though the P-chain is responsible for generating the force that propels us forward in a sprint or upwards in a jump (along with the quads of course), the A-chain works in a couple of different, though no less important, ways.
The first purpose the A-chain serves is as a pelvic stabilizer during athletic movement, primarily whilst running. The abdominals and hip flexors work in concert with the glutes, hamstrings, and spinal erectors to control the positioning of the pelvis and ensure the optimal transfer of force across the hip. Weakness through either the abdominals or the hip flexors (the rectus femoris and illiopsoas) can cause the pelvis to rotate either anteriorly or posteriorly and reduce the leverage of the propulsive muscles (the quads, glutes, and hamstrings) or put the body in the wrong position to generate force in a movement immediately following.
Looking at running specifically, if the abdominals aren't strong enough then the pelvis rotates anteriorly and the trail leg will tend to flail too far behind the body after each stride. If the trail leg is allowed to travel excessively far back before it's brought forward to get ready for the next stride, then the athlete's illiopsoas and rectus femoris will rarely be strong enough to bring it back around in time to assume the optimal position during the support phase (ground contact phase) of the opposite leg. If the leg isn't brought around in time and doesn't find the optimal position then the athlete won't be able to generate optimal power in their next ground contact (Bosch and Klomp, 2001). And since sprinting is a cyclical activity, the problem will perpetuate itself during the following leg cycles, essentially handicapping force production, and therefore speed, with each stride.
As you can clearly see, abdominal strength is huge in determining sprint speed, but surprisingly enough, so is powerful hip flexion. Though it's somewhat counterintuitive, studies have shown that hip flexion strength is a better predictor of sprint speed than is hip extension strength amongst trained athletes (Blazevich & Jenkins, 1998). Similarly, other studies have demonstrated significant decreases in short sprint (3.8%) and shuttle times (9.0%) after a period of hip flexor training (Dean et al, 2005) and have found a link between larger illiopsoas (when compared to the quadriceps) and 100M speed (Hoshikawa et al, 2006). But how do strong hip flexors make you faster, you ask. There are two ways.
The first way in which the hip flexors help generate speed is through faster and more complete repositioning of the leg after it has left the ground. By moving the leg back into position faster and having the strength to move it higher, the athlete will demonstrate greater frontside mechanics when they run. What this means is that the legs will spend more time in each cycle in front of the body rather than behind it (backside mechanics). If one takes a look at top sprinters and compares them to average , slower athletes, the first thing they'll notice is the different in mechanics.
When sprinters run, they display a neutral or posteriorly rotated pelvis, high and fast knee lift, and their legs spend more time in front of their body than behind it during each sprint cycle. The reason for this is not because of the time they spend on technique, but because they have strong enough abdominals and hip flexors to hit such positions.
In stark contrast, when a slower athlete runs, their pelvis will oftentimes be anteriorly rotated, their knees won't reach nearly as high, and their legs will flail back behind them after each stride. They can try to hit the same positions as a sprinter, but won't be able to do so effectively because they simply lack the strength in the relevant muscle groups (the anterior chain).
The second way in which powerful hip flexion strength can aid in speed is through something called the inverse-extension reflex. The inverse-extension reflex is an involuntary mechanism which causes the hip flexion of one leg to facilitate hip extension of the opposite leg (Bosch and Klomp, 2001). A more powerful flexion of one leg will lead to a more powerful reflex-potentiated extension of the opposite leg. In this way, the strength of the anterior chain will actually direct increase that posterior chain. Pretty cool, huh?
So, as you can see, if you're an athlete who's sport requires them to run, regardless of the distance, then training for the anterior chain is a must, and I don't just mean doing high rep crunches in between sets either. As is the case when training for any sport, muscles are best trained the way they will be needed to function on the field, and the A-chain is no different.
Taking a look at conventional A-chain training, there's really not much “chain” work going on at all. Crunches are a long time favorite exercise of the casual gym goer, but they're completely ineffective for two reasons. One, they take the hip flexors entirely out of the movement and therefore aren't of much more functional use than a leg extension. Two, the abs are muscles too, they need load in order to get stronger and grow. And don't think squatting will cut it either, because it won't.
All too often people get to talking about how squats and deadlifts are the best core exercises, but in this case, they'd be sadly mistaken. Though the abdominals are called in to stabilize, the brunt of the load of both exercises is taken by the quads and p-chain, most notably the spinal erectors. So while you can build a strong back with two of the classic powerlifts, and in an integrated movement pattern no less, you won't be doing much for the front of your body.
In order to best train the A-chain, you've got to train it just like you would any other part of your body, in sequence with the relevant muscle groups (in this case we're referring to training the abdominals and hip flexors together) and under a heavy load (sorry, but there are no 50 rep 'burn' sets here).
Also, since it's fairly common to develop problems with overly shortened or tight illiopsoas, all of the prescribed exercises will work them at an extended length and over the range of motion in which they'll be called upon to perform in sport. Since muscular the tension and length of the muscles (aka flexibility) is controlled primarily by neuromuscular processes (Siff, 2003), training the muscle group in a lengthened state will promote better active flexibility gains than stretching alone (Iashvili, 1982). Meaning, if you train them in a lengthened state, you'll never have to worry about tight hip flexors again.
Now that we're done with that, let's get to the training recommendations. I'm not going to outline an actual program, but I am going to suggest several very useful exercises for building up your certainly lagging A-chain and explain just what they do and why/how.
Split Squat
The split squat is like a almost exactly like a lunge, except that once you get your feet planted they stay there for the rest of the set and you merely rise up and down instead of taking a step forward or backwards. In order to do the exercise optimally, it's necessary that you position your feet so that four things happen:
1) At the bottom, your front shin is perpendicular to the ground and your weight is on the heel.
2) You're able to maintain a neutral (not arched) back. (This will take some abdominal control.)
3) The weight is distributed evenly between the hip extensors of the front leg and the hip flexors of the rear leg.
4) You can keep your legs in line throughout the movement (no knees or ankles externally rotating).
If done correctly, the split squat trains the hip extensors of one leg in concert with the hip extensors of the other and it does so at the length they'll be used at while running. Similarly, the act of keeping a neutral pelvis throughout the set will help to coordinate the abdominals with the hip flexors and extensors. This increased coordination will show up on the playing field as greater speed and stability while moving.
The movement does have a problem though, and that's that it's performed over a relatively small ROM. This can be dealt with quite easily though. To get the most out of the movement, I suggest doing sets of 5-8 reps per leg with a paused isometric hold of 3-5 seconds at the bottom of each repetition. Either a barbell or dumbbells can be used to add load.
Ab Bench Holds
When sprinting, the primary type of strength required by the A-chain is isometric in nature. At the moment the leg transitions from going back to being brought forward it's isometric strength that determines the speed of the movement, and this isometric strength needs to be displayed over a very specific range of motion. To develop this strength, we turn to the decline ab bench.
Usually used to perform sit ups, the ab bench can be a culprit in producing overactive and tight hip flexors, but we're going to get around that by performing the exercise with the illiopsoas in a lengthened position while simultaneously coordinating them with the abdominals.
In order to do this exercise properly, get in an ab bench or decline ab bench just like you normally would and put your pelvis into a neutral position. Lean your torso back as far as possible while maintaining a neutral pelvis, stopping when your back starts to arch (go into extension). Now, once you've reached that position, just hold for time. I recommend sets of 20-30 seconds.
The above variation strengthens the abdominals more so than the hip flexors, but this can be fixed by performing the exercise with only one leg hooked into the bench and the other allowed to stay free. Performing the holds in this manner will primarily stress the illiopsoas and rectus femori while putting less stress on the abdominals. Think of it as single leg work for the front side of your body.
Depending on where your weakness lies, you can pick and chose a variation.
Leg Lowering Holds
The final strength exercise I'm going to recommend is the leg lowering hold. To perform this exercise, lie on your back and stick your legs straight up in the air while keeping them together with the knees locked. Bracing your upper body if necessary, slowly lower your straight legs towards the ground while focusing on keeping your lower back on the ground. To keep your lower back on the ground, you'll need to prevent your pelvis from anteriorly rotating by contracting your abdominals. Only lower your legs as far as you can while keeping your lower back firmly on the ground.
Once you found how far you can go before form breaks down, just hold your legs there for 20-30 seconds. To make the exercise more difficult you can do two things. One, you can try to get your legs closer to the ground, but this will require higher levels of control and flexibility. And two, you can hold a DB between your feet. Don't add load until you can get your heels within 6-12” of the ground while maintaining form.
Like the ab bench holds, this exercise works the A-chain isometrically and helps to coordinate the firing of the abs and hip flexors.
Out of the Weight Room
Once you've built up your strength in the weight room, you can bring your new strength and movement patterns out on to the field of play by using a few higher velocity, lower load exercises. Here's where you first get to witness the rubber meeting the road.
-Sprints (30-60M in length)
-Hill Sprints (again, about 30-60M in length)
-Broad Jumps
-Tuck Jumps
-Kicking a heavy bag
-A-skips and B-skips
By keeping the discussed principles in mind and applying the recommended exercises for the often ignored A-chain, you'll be able to balance out your body and take your sport performances to the next level. But don't go overboard. Balance is everything, and making sure to train your body from all sides (A-chain and P-chain) is more important than developing strength in a lopsided manner.
So, while it's not glamorous, and won't get you many glances from the hot gym bunnies, hammering your A-chain is necessary if you want to reach your fullest potential.
References:
Blazevich AJ, Jenkins DG (1998) Predicting sprint running times from isokinetic and squat lift tests: a regression analysis. Journal of strength and conditioning research Vol 12: 101-103
Bosch F, Klomp R (2001) Running: Biomechanics and Exercise Physiology Applied in Practice. Reed Business Information
Dean RS, Chow JW, Tillman MD, Fournier KA (2005) Effects of hip flexor training on sprint, shuttle run, and vertical jump performance. Journal of strength and conditioning research 19(3): 615-621
Iashvili A (1982) Active and passive flexibility in athletes specializing in different sports. Teoriya I Praktika Fizischeskoi Kultury 7: 51-52
Siff MC (2003) Supertraining 4th Ed. Supertraining International, Denver
RJ Quotes
"I've read the works of the heavyweights in the field and I see gaps in even their thinking, understanding, and organization. They may have more experience than me, but I wouldn't say they know more. Coaches can only apply so many different physiological stimuli in so many patterns and I can outline the effects of most down to a cellular level. As far as we, as coaches, are concerned, the rabbit hole only needs to go so deep."
"And I know a grasp on science alone isn't enough to be a coach. One of the biggest things I've learned over the past couple years is how practice rarely mirrors theory. However, with a good psychology background and people skills (for understanding the athlete), scientific knowledge, a bit of intuition, and the understanding that perfect is often the enemy of great, it's a piece of cake.
"While I'm obviously still not at the pinnacle of my writing/sports science career, skill acquisition is asymptotal and, at least in areas concerning training, I'm near the asymptote. I've put in an ungodly amount of time and I believe I have plenty to show for it. I can compare my works to those of Bompa, Verkhoshansky, and Zatsiorsky and I don't find myself lacking. In areas of specific study, I don't know as much about nervous system function as Enoka, or as much about tendon and fascicle function as Kubo, but I can take their ideas and findings and integrate them into a complete training plan without difficulty. In areas like nutrition and biochemistry, I still have A LOT to learn and I'm working on it."
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A revelation: extreme statements tend to be misleading and/or stupid. P-CHAIN IS BOSS SQUATS ARE ALL YOU NEED FOR ABS was always a retarded thing to say. Also, since when has the A-Chain been the less glamorous side? Isn't bench, curls and abs the beach bro trifecta?
Gonna try those exercises he describes at the end.
Thanks for posting, Lance.
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Great article, very interesting.
Does Roger Nelsen still post on here?.
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Great article, very interesting.
Does Roger Nelsen still post on here?.
nope