Through my many years of experience working with athletes and analyzing athletic performance, I have learned how to evaluate and assess body movements in three dimensional (3D) analyses. From these 3D studies, I have learned to measure, analyze, and compare movement and loading patterns of elite athletes in a number of different sports. My experiences have taught me of the importance of proximal-to-distal kinematic sequencing and how these elite movement patterns translate to elite loading patterns in the Kinetic Link, which is found in all elite athletes to varying degrees.
Because of these experiences, I have a very thorough understanding of what actually happens in elite athlete movement and loading patterns. As importantly, I have also developed a firm understanding of what non-elite level athletes or amateurs do incorrectly in their movement patterns, or more appropriately what they do inefficiently. As a biomechanics specialist, the ability to quantify these inefficiencies in movement and loading patterns is a critical goal of the performance analysis. As a biomechanics trainer, understanding how to correct these inefficient movement patterns is the critical goal of the training work.
Having worked with both professional athletes and amateur athletes, as well as working with coaches and trainers to both classes of athletes over the years, I have had the opportunity to observe and listen to their thoughts on what causes these inefficient movements and how to correct them. The goal of any athlete, regardless of their current skill level, is to become more efficient in their movement patterns resulting in more optimal, powerful loading patterns. So it would seem that the ultimate goal is to develop training programs that correct these inefficient movement patterns.
But what if the coach or trainer has an incorrect understanding of what needs to be corrected? In the modern world with instant access to very advanced biomechanical analysis and training studies via the internet, one would think that would not be a problem. However, I have talked with a number of professional and amateur athletes, as well as their coaches and trainers, who have a very fundamental misunderstanding of how the human body actually functions. These same thoughts are perpetuated in online sports performance forums, coaching and training clinics, and fields and gyms across the country.
The biggest misunderstanding of how the human body performs is the concept that all human motion and loading starts at the ground and works its way up through the body. This is fundamentally not true in elite movement and loading patterns. Unfortunately, the majority of the misinformed use still-frame pictures of a high speed motion events to support their argument that movement and loading start at the ground and work up the body. However, this fundamentally defies how the human body is organized and specifically the concepts of kinematic sequencing and the Kinetic Link.
So if movement and loading does not start at the ground, then where does it start? In simple terms, it starts in the middle of the body, the core, for EVERY movement we as human beings perform. In reality, there are some very inefficient movement patterns that don’t start in the core but rather initiate at more distal segments. However, these movements are by definition inefficient if they do indeed start at the more distal segments as opposed to the core of the body.
The term that I like to use for how the human body actually moves is “Move the Middle.” I believe that this perfectly articulates any efficient human movement pattern, either from an analysis viewpoint or from a training perspective. If movement or loading is started in the middle or the core, then the important concepts of proximal-to-distal kinematic sequencing and the resultant Kinetic Link can take hold resulting in the most efficient movement patterns for the necessary motor control task. Steve Englishbey of Englishbey Hitting is one of the few sports performance trainers out there that truly understands this. In his DVD’s and forums, he has done an outstanding job of articulating these concepts. He was the first person that I came across in my research that also used the term “Move the Middle” in his analysis.
Brent Pourciau of Top Velocity also does a very good job of describing motion starting at the core in his pitching programs and video posts. Most people see his 3X triple extension pitching programs and think that his concepts of triple extension of the hip, knee, and ankle joints start from the ground up because he uses resultant force vectors showing forces from the ankles through the lead hip. But Brent does a good job of explaining that the motion and momentum is due to core/pelvic movements and the ground reaction force vector is in fact a RESULTANT force vector caused by these motions.
I have been challenged a number of times in conversations or in online forums when I debate this fact. You would not believe how many people insist that elite movement patterns start at the ground. They usually offer a 2D still image from some sports movement to try and prove their point about movement starting from the ground. But using a photo snapshot of a very dynamic sequencing event is not a very good methodology to try and prove this point. And this thought process does not come from just weekend warriors or local trainers. This prevailing mentality is ingrained in the highest level professional athletes as well as their nationally recognized coaches and trainers.
A great example of this is in discussions of “squishing the bug” in baseball hitting mechanics. Countless coaches and instructors use the audible cue of “squish the bug” when teaching rotational hitting mechanics. The problem with this, is that it enforces a movement and loading pattern starting from the ground. By simply “squishing a bug” movement with our back foot, we do indeed ultimately internally rotate our back leg; however we do that at the expense of any powerful hip rotation. What happens in reality is that powerful hip rotation causes a RESULTANT internal rotation of the back leg, eventually ending with a “squish the bug” position in the back foot. In the most powerful athletes in MLB, many end up with the back foot completely off of the ground. No way this happens if movement and loading starts from the ground up.
A much better way to analyze human motion is through video, and animated gifs provide a powerful method for displaying high speed motion. While the photo of Albert Pujols above may demonstrate the Move the Middle concept, an animated gif of the entire motion provides much more detail. In the animated gif of the swing of Freddie Freeman below, it is very easy to see that his swing starts from his pelvic/core motion and his legs simply react to that motion. The resultant leg motion is simply a product of the pelvis being moved while the feet are subject to motion constraints at the ground.
Why am I so sure of the “Move the Middle” philosophy? Because I understand how the human body is organized and functions. I do not use still images to develop and test movement pattern hypotheses. I have been very fortunate to have been exposed to advanced measurement technologies for 3D studies including motion capture systems, MEMS based inertial measurement units, force plates, as well as electromyography (EMG). While utilization of these technologies has obviously helped with my advanced understanding of how elite athletes move and perform, it is not a requirement. In fact, just an understanding of how the human body musculoskeletal system is organized and functions provides all of the answers without the need for these advanced measurement technologies. But too many people disregard these facts and look to 2D sequences of still images to show movement starting at the ground to support their hypothesis. But this is fundamentally false in every circumstance.
I will show why the following 2 statements pertaining to movement and loading starting at the ground are false:
- Human motion does NOT start from the ground and work up the body.
- Human load or energy creation does NOT start from the ground and work up the body.
The second statement is the one that causes the most controversy. I will also show that the following statement addressing loading is true:
- The human body’s reaction to resultant loading does start at the ground interface through a motion constraint.
The following 3 key attributes can be used to best explain why EVERY human motion starts, or should start, through a “Move the Middle” philosophy:
- Joint Angular Kinematics: As discussed in the blog post about angular kinematics, the human body is composed of only rotational degrees of freedom (DOF). There are no translational DOF in human joints. All human motion results from angular rotation of one skeletal bone relative to another through muscular contractions. So if movement patterns truly start from the ground up, then it should be the case that the joint angular DOF at the joint nearest the ground (ankles) provide the motion and loading required for powerful movement patterns. The human ankle joint is a combination of two joints: the ankle, or talocrural (TC), joint between the tibia-fibula and the talus; and the subtalar, or talocalcaneal, joint between the talus and calcaneus. This complex permits three rotations or joint DOF: a.) plantar-dorsi flexion; b.) inversion-eversion; and c.) external-internal rotation, or abduction-adduction. So if human movement, and more importantly, loading originates at the ground and works up the body, then these 3 movement DOF should provide extremely powerful motions by themselves. So let’s do a little science experiment at home and try these out. First, lets test abduction-adduction of the ankle joint. Stand straight up and lock every joint in the body in a neutral position. Now move your toes medially (in) and then laterally (out). Feel that power! See how fast you are moving! No – you are just spinning your foot side-to-side with little to no speed or power at all. Now, let’s examine inversion/eversion. Lock out all of your joints in a neutral position except we are going to roll the sole of our foot inward with the weight on the outer edge of the foot. Feel all of that power now! No – you just feel like your ankle is going to pop and you will fall over. Well then eversion must be the key. Roll the sole of your foot outward with the weight on the inner edge of the foot. Ah, there’s the power. No – even less range of motion and a very unnatural feeling due to the bony constructs. Finally, let’s test plantar and dorsiflexion. Lock out all of the joints in your body except we will test plantar flexion. Move the sole of your foot downward so you end up with all of the weight on your toes, as in a calf raise. There we go, now we are actually moving! This has to be the key to a 42″ vertical leap. No – we only raise our center of gravity about 2″. Starting to now question that all movement and loading patterns start at the ground? Well why? Maybe just because we can only spin in place or raise up about 2″ and actually move NOWHERE with only our ankle joint DOF rotations. You should start to get the idea that motion is really not initiated at the most distal segments right about now. Let’s even extend this argument to the next joint up the kinematic chain – the knee joint. The knee joint is a simple hinge joint in which we can only flex or extend the knee. Now if you stand neutral and lock out all of the other joints, especially the hips, you can only flex your knee backwards. At least we are finally moving something, but we still have no ability to move from point A to point B yet. None. With the 4 DOF discussed so far, we can not physically move to another location. We can only spin on the ground, shift our weight on our heels or toes, and lift our lower leg backwards. Doesn’t really seem like a very powerful way to move does it?
- Glutes: Taking a more theoretical perspective, would it not make the most sense to have the strongest, most powerful muscles acting across the skeletal structure that is at the center of all motion (rotations)? Guess what muscle of the approximately 650 muscles in the human body is the strongest? The glutes – as described in Men’s Health The Book of Muscle and by Bret Contreras – The Glute Guy. As Bret Contreras states, “… the gluteus maximus muscles are without a doubt the most important muscles in sports.” But he also adds that “… athletes’ glutes are pathetically weak and underpotentialized. Even people who think they have strong glutes almost always have very weak glutes in comparison to how strong they can get through proper training.” Kelly Baggett of Higher Faster Sports is an Arizona-based “performance consultant” who specializes in “increasing raw explosiveness, acceleration and jumping ability. In Baggett’s article “The Plague of the Mediocre Athlete” he argues that the glutes are mainly responsible for the ‘horsepower’ factor and does not believe that an athlete can have too much glute strength. He maintains that “due to their natural strength and the leverage advantage they have over your legs, the glutes should always be the primary muscles that drive lower body movement.”Getting back to our sit at home science experiment, let’s try the following. Standing in a neutral position locking out all joints now, let’s examine the hip joint DOF. First flex our hip; now we can at least see how we can start to move from point A to point B as the movement at the proximal joint (hip) physically moved the distal joints (knee and hips). Next abduct one of your legs by moving it straight sideways away from the body. Now we can see how we move laterally. Finally looking at medial/lateral or internal/external rotation shows that we don’t get much movement, but we do get a very powerful rotation, moving the distal segment (foot) sideways. When you combine the three hip joint DOF, you start to see how the human body really moves. When you start adding some knee flexion to this AFTER motion at the hip joint, we really can start moving from point A to point B. But we can’t get anywhere without moving the hip joints first, and that is the key to human movement.
- Transverse Abdominus: Mark Verstegen of Athletes Performance is another elite sports performance trainer that talks about the concept of “Move the Middle” and the importance to elite movement patterns. In his amazing book Core Performance Mark expands on this concept: “All movement starts from a remarkable muscle called the transverse abdominus (TA). Think of the TA as nature’s weight belt. It originates from the lower spine and wraps around and attaches to the ribs, abdominals, and pelvis. When we draw the belly button in toward the spine and up toward the ribs, we’re essentially tightening a belt, ensuring the protection of the pelvis and lower back. Your natural weight belt stabilizes the pelvis and supports the torso. Whenever movement begins, the TA is the first muscle that fires – or, at least, it should be. For many people, that ability is lost over time on account of injuries or sedentary lifestyles…If we can learn (or relearn) how to activate the TA, we can rely on nature’s weight belt and not wear additional support. We’ll be able to stabilize the pelvis so that the leg and torso muscles can turn to it for support. That, in turn, prevents back problems. The body will be able to transfer force efficiently through the muscles rather than through the back and joints…The pelvic muscles are important and work in conjunction with the TA to give you great stability.”
Taken together, these 3 key attributes demonstrate that any optimal movement pattern should follow a “Move the Middle” philosophy. Mark Verstegen does a great job summarizing the importance of the core area in optimal movement patterns: “We have a tendency to think of movement as starting from the limbs. If we reach out to grab something or step forward, we think of those motions as originating with the end result – we’ve reached out; therefore, we’ve used our arms. We’ve stepped forward, so we’ve worked our legs…Movement, however, starts from the very center of the body, the core area of the torso. Amputees can still function and have fulfilling lives because their core remains intact. Frostbite begins at the fingers and toes, areas farthest from the core, because the body wants to protect what’s most important and concentrates its lifesaving heat around the vital organs at the center of the body. That’s why we refer to the torso as the pillar – it’s the structural center of movement and life. The way that we maintain that pillar and its alignment and function directly correlate to the health of the our organs and the rest of our bodies. Everything is interrelated. Pillar strength, thus, is the foundation of movement. More specifically, it consists of core, hip, and shoulder stability. Those three areas give us a center axis from which to move. If you think of the body as a wheel, the pillar is the hubs, and the limbs, the spokes. We want to have the hub perfectly aligned so that we can draw energy from it and effectively transfer energy throughout the body. It’s impossible to move the limbs efficiently and with force if they’re not attached to something solid and stable…The better you can transfer energy through your body, the more efficiently you will move, and the less wear and tear there will be…Everything in your body is connected and related through this pillar of strength. Your shoulders and spine are related to the core and glutes, and they’re interwoven in cross patterns that need to be tuned from maximum efficiency.”
So the biggest question is why do so many people, including some of the supposedly best trainers and coaches in the world and even the most elite professional athletes get confused with this concept? There are 3 main concepts that cause this confusion:
- End Effector Mobility: In many human movements, the last link of an open kinematic chain, typically the hand or the foot, needs to be positioned in a specified place with a specific orientation. This is exactly what Mark Verstegen was referring to before. This link is termed the end effector. This concept is very similar to end effector robots that use robotics to position the arms at a specified 3D position and orientation. For a more detailed discussion, see the blog post about end effector mobility.
- Kinematic Chains: One of the hardest concepts to understand for most sports analysts and trainers is the effect of different types of kinematic chains on resultant loading with the ground or hand-held implements (weights, bats, clubs, tools, etc.). While this applies mainly to dynamic modeling of human motion and solving the dynamic system of equations, the concepts also apply to understanding the conservation of momentum and its application to different kinematic chain problems. For more detail, see the blog post about kinematic chains and their applications to sports performance analysis. Some sports activities are harder to describe and analyze because the athlete will change the kinematic chain body positions during the activity: baseball pitching is one of the more difficult sports motions to understand loading as the pitcher goes from single stance on pitching side leg, to double stance during powerful hip and shoulder rotations, to single stance again on glove side leg at the finish. This change in loading scenarios with external systems can cause a lot of confusion with movement patterns based on changes in resultant ground reaction forces.
- The Earth: What in the world does the Earth have to do with misunderstanding of human movement patterns? Quite a bit actually. The answer is the mass, m, and moment of inertia, I, of the Earth. And specifically, the nearly infinite mass and moment of inertia of the Earth when compared to the athlete. Most people are familiar with Newton’s 3 laws of motion for translational motion. Not as many people are as familiar with the analogous laws governing angular motion, which is directly applicable to human motion as all movement is based on angular kinematics as discussed previously.
- The second laws can be expressed mathematically by the following equations.Newton’s 3rd Law seems to be where people get most confused. This law states that every force (or torque) involves the interaction of two objects. When one object exerts a force (or torque) on a second object, the second object also exerts a force (or torque) on the first object. The two forces (or torques) are equal in strength and oriented in opposite directions. Where confusion comes is that many people think that the ground or ground foot interface initiates the motion and loading. But in reality the ground is just where the action-reaction of the 3rd law takes place between the momentum developed in the body and with the physical constraint (motion constraint) of the Earth. And the physical constraint of the Earth is very real and very large. Meaning that there is no negligible movement of the Earth from the athlete-ground resultant action force and torque; rather the athlete is the one that is propelled relative to the Earth from the resultant reaction force and torque. The Earth’s mass and MOI are so large compared to the mass and MOI of the feet that it is essentially infinite. The athlete does indeed create an action force and torque acting on the Earth as described in the 3rd law. It just has no noticeable effect on the resultant path and orientation of the Earth’s movement; it just gets swallowed in the enormity of the Earth. The athlete on the other hand does indeed react to the resultant reaction force and torque at the ground interface and is propelled or turned in the direction dictated by the reaction force and torque.
Some real life examples will hopefully help explain how humans perform by moving the middle and how the previous concepts affect this. One example I look to use to demonstrate the effect of body rotations in the transverse plane and angular momentum is having the athlete stand on a swivel office chair. If the athlete then starts a golf swing or a baseball swing by counter-rotating the shoulders closed, what happens? Through angular momentum, the chair spins the hips open in the opposite direction. Why does this happen? Because we removed the physical constraint of the Earth on our feet. The Earth is too big and we are too small to spin the Earth. Rather, resultant torque is just developed at the ground-feet interface in an actual swing. Because the swivel chair removes the rotary physical constraint of the Earth, we actually see the resultant angular motion of the hips in the opposite direction. This shows that motion does indeed start in the core/pillar, and angular momentum from that motion causes reactions downstream.
Another good example is that of a swimmer’s start in the pool. In this application, we do have a physical constraint in the wall that the swimmer pushes off of. It is just a vertical wall, as opposed to a horizontal surface we typically see when performing sports movements on the Earth.
When a swimmer, either facing the wall or away from the wall, places her feet on the wall and pushes hard, what happens? She accelerates away from the wall by applying a force to the wall, but her motion indicates that a force is being applied to her, too. This force comes from the wall, and it’s equal in magnitude and opposite in direction. Where did this force come from? It comes from the powerful extension of the hips, knees, and ankles against the physical constraint of the wall. The purely angular kinematics of the swimmer provided a purely horizontal resultant loading propelling the swimmer through the water.
We can apply this same analysis to someone performing a vertical jump. Looks pretty much the same if we just rotated the previous swimmer diagram counter-clockwise. The only difference is that we now have a physical constraint in the vertical direction and the resultant momentum causes a purely vertical acceleration of the athlete. We also now have gravity directly affecting the loading scenarios. But the motion again starts from a triple extension of the hips, knees, and ankles against the physical constraint of the Earth.
Another good example to demonstrate the concept of angular momentum powered by the body without any physical constraints from the Earth are squid movements. A squid moves by jet propulsion—as the mantle opens, water is taken in; as the mantle closes, the water is expelled through the siphon, a nozzlelike structure below the eyes. By bending the siphon, the squid can swim in any direction; however, it usually swims backwards. Same concept of the swimmer pushing off of the wall or the athlete performing a vertical jump, except there is no ground reaction with the Earth. Rather the energy is transferred from the squid to the surrounding water.
Also, aerial high divers demonstrate the concept of conservation of angular momentum both with and without temporary physical motion constraints. At the start of the dive, the diver performs similar movement patterns to that of the vertical jump example. Once airborne and the physical constraint is removed, the athlete uses body powered angular momentum to spin through the air.
An analysis of the world’s fastest mammal, the cheetah, provides an excellent summary of how speed and power is developed. When watching the linked video, pay attention to how far the cheetah’s hip joints move. This is the reason for their incredible speed which reaches up to 75 mph. It has nothing to do with the ground providing more power. Rather it is due to their incredible hip motion that provides extreme power as they accelerate off of the same temporary physical constraint that we use to run on. While there are physical differences in their hip joints and flexible spine, the incredible range of motion of their hips provide the unbelievable acceleration they have as they can get up to 60 mph in only 3 seconds. Again, moving the middle provides all of this power and speed.
By now, one should be convinced that elite movement patterns do not start from the ground up; but rather they start from the core and move out in a “Move the Middle” phenomenon. And if your coach or trainer still believes in teaching the “ground up” movement philosophy, then you better find a new one if you really want to achieve your best performance.