How does the body get things done?
Walk, run, stand up, sit down. All are activities that, barring physical disability, we all perform every day. However, the body does not follow a singular pattern to accomplish the task. Those movements alone can cause dysfunction. Once we get into more complicated movements (although those are all complex enough) such as throwing, jumping, and lifting, the body starts to use those altered patterns of movement to accomplish the task with the least amount of energy needed. Depending on the amount of limitations of the person performing the activity, the movement pattern can be very efficient or very debilitative. Regardless of the limitation however, the body will find a way to get the activity accomplished.
Lets take a look at running. Running is the most popular form of cardiovascular exercise in today’s society. Everyday, I see runners on the roads, sidewalks, on the treadmills and anywhere else you can imagine a runner going. This is a great example of the body doing whatever it can to accomplish a task. Everyone does not have the same form in running. In fact sometimes I wonder if half of the runners and in extreme pain, or perhaps wounded.
There is a reason that professional athletes have a more fluid, efficient, movement pattern.
Front Butt and Back Butt in Gait
I often hear from clients, friends or fellow runners that they pulled their hamstrings. Although a pull is a much more serious injury than they are explaining most the time, what they are explaining is that, due to running, their hamstrings are uncomfortable. The hamstrings are obliquely located in the backs of the upper legs, and although there are many exercises to work the concentric movement of the hamstring in the sagittal plane, their function is actually to eccentrically decelerate motion in the transverse plane. Due to the collapsing of the foot (unlocking of the sub-talar joint), which forces the tibia (which sits on top of the talus like a horseback rider) to move into a transverse plane, driving the knee which will go into relative abduction and the hip into adduction and internal rotation, will turn on the glutes and hamstrings to control the lengthening and deceleration of motion in the transverse plane.
So when a client tells me that they are having hamstring pain, I can start at the foot to see if it is the culprit. However, another place that I look at often, is the opposite hip flexor (front butt). Since our culture is now very sedentary and is usually seated throughout the day, hip flexors can get tight and cause opposite hamstring pain, if you can believe that!
Putting a client into stride position, with the dysfunctional hamstring forward, many times the back foot will be turned out (due to tight hip flexor complex) and they will have trouble maintaining balance in this position. Throwing in different arm movements such as sagittal overhead reaches, overhead lateral flexion and rotational reaches, will help single out some problem areas that the body may not be dealing with properly. Often times, the client will be unstable, will arch their lower back, and do whatever is necessary to complete the arm reaches, whether it be dysfunctional or not.
If the hip flexor that is now being lengthened, is tight, it will use up all the motion it has very quickly. Therefore, when running, the hamstring will now have to make up for the rest of the motion that is needed to take a stride. While you are running long distances, you are taking thousands of strides, repeating this inefficient movement over and over again. Without a proper hip flexor controlling tri-plane motion and allowing the hamstring to focus only on what it should be doing, the hamstring will get overused and tired, leading to pain. In this case, most people stretch the hamstring, however you do not want to make it more angry! Stretch the real culprit, the hip flexor, (in all 3 planes of motion of course) and the hamstring will start to relax, because it can focus on it’s job, not juggling two jobs at once.
What do the feet have to do with my knee pain?
Now we can start to look at the feet. Since the foot controls the tri-plane motion (tibia traveling in the sagittal plane over the foot, the foot collapsing in the frontal plane, leading to the transverse motion created by the collapsing of the foot and the tibia being driven down in internally roated) if the foot’s not doing it’s job to control motion, the knee can be exposed to a lot of pressure due to a less efficient shock absorption. If the foot does not pronate (collapse) as it is supposed to, there are certain planes of motion that will be limited and shock absorption will be less efficient, leading to more stress on joints and muscles up the chain. Gravity and ground reaction forces (GRF) are a principle of physics. They are undeniable truths. Taking this into consideration, the body must be looked at while vertically loaded (standing), when gravity is effecting it the most. When the foot hit’s the ground, and the foot collapses in all 3 planes of motion, there must be a load of the body (like a stretch of a rubber band) to allow the body to propel itself to the next position that it wants to be in (release of the rubber band). We will continue to look at running to explain this. When we are running, we are basically fighting gravity to get from one point to another. When our front foot hit’s the ground, stance phase, our body must absorb the shock from the GRF’s. Therefore, there must be an efficient load of the foot and front leg in gait to eventually push off and propel our bodies forward for the next step.
What is the knee extensor in gait? Not the knee!
Taking a look at some of the muscles that help load our front leg in stance phase, we start with the neighbors of the foot. The gastrocnemius, the soleus and peroneus longus are 3 main muscles that help decelerate the motion of the lower half of the leg. If these muscles were not efficient, we could not effectively slow ourselves down and would fall flat on our faces. The gastrocnemius and soleus are located posterior to the tibia and fibula, while the peroneus longus is laterally positioned and ends up attaching under the foot on the medial side. When the foot hit’s the ground, as we had previously mentioned, the tibia travels in the sagittal plane over the foot, the knee abducts, and internally rotates the tibia. Therefore, the foot is dorsi-flexed, causing the gastrocnemius to decelerate the tibia in the sagittal and transverse planes, while the peroneus longus, which wraps under the foot lengthens to decelerate the foot in both the frontal and transverse planes, allowing the foot to pronate and supinate when needed. If we can understand what the lower leg musculature can control, we can now assume that, contrary to previous beliefs, the quadriceps muscle group does not actually extend the knee in gait. Open your mind for this one! The calf muscles are the knee extensors in gait. The lower leg musculature must decelerate the motion of the leg to allow the femur to eventually speed up faster than the tibia.
Summary
The body is a complex structure. Looking only at the muscles concentric function, lying down, unaffected by gravity, does not allow us to feed function for the body. Lower back pain, knee pain, shoulder pain, etc are all common injuries that occur. Usually, these are not due to the lack of strength in the muscle, or joint, but in fact a dysfunction of the joints above and below the pain. Since the body works as one unit, it is important to look at the reaction of the whole body in the task. Just because a person has hamstring pain, we should not just focus on strengthening that hamstring. In fact it may be too strong and it is being overworked. We must look at the whole body as a structure working as one to efficiently move. Regardless of the task, the body will find a way to accomplish what it needs to. However, when there is compensation throughout the body’s neuromusculoskeltal system, there will be dysfunction and pain.
My discussion was drawn largely from my education from the Gray Institute and Chain Reaction Seminar given by Gary Gray and Dave Tiberio.
Thanks to the Gray Institute and those who help me learn as a student of Applied Functional Science
Gray, G., Tiberio, D. “Chain Reaction Seminar.” Gray Institute. Orlando, FL April, 2010.
Will Greenberg is a certified Personal Trainer through NASM and NSPA. He is a student of Applied Functional Science and is currently pursuing his CSCS.
By understanding undeniable truths of physics, such as gravity and ground reaction force, we can understand how the body functions in a vertically loaded position. The traditional anatomical function of the body is looked at while the body is on a table or parallel to gravity. Once there is a vertical load (gravity) placed on the body, the function of the body’s structure changes. Will’s ultimate goal is to understand the function of the human body and apply that to his clients.
