Human Engineering: Dynamic Stability/Body Mechanics – Upper Extremities

Human Engineering: Dynamic Stability/Body Mechanics: Upper Extremities

(see part 1 of this series here)

(see part 2 of this series here)

(see part 3 of this series here)

by Sanjeev Joseph

Physical Therapist, CEO, Innovator, Educator passionate about fixing bodies and changing lives

I recommend you read Part 1, 2 and 3 of this series before learning the upcoming concepts. If you have done so, congratulations, you are one step closer to understanding the secrets to human movement and the physical laws controlling your body. Use the following concepts as tools to help preserve your body, while at the same time increasing output. In other words, enjoy the efficiency!

Dynamic Stability: Upper Extremities

In Part 3, you learned about Dynamic Stability of the Lower Extremities. It is essential to know these concepts before proceeding to Part 4, which dives into the Upper Extremity Biomechanics. Why? For starters, all movement involves the core. But especially important for upper extremity movements is having a solid foundation in your lower extremities. Take a boxer for example. He can’t throw an effective punch without having his feet planted on the floor, hips and knees engaged, and the force passing through the core and finally out through the upper extremity. So with that said, let’s jump right in.

What To Focus On

The focus, when using the upper extremities is to always keep the spine in proper alignment with the shoulders and hips. This will keep all the forces in a neutral playing field, allowing for optimal and efficient energy conservation and conversion. In other words, the more balanced your body is, the less energy you waste during activities that involve the arms.

Lifting From Floor

In Part 3, you learned how to do a proper squat. To lift something, from the floor, you will need to get into the squat position. The object you are lifting should be as close to your body as you can get it. Then use your hands to grip the object and pull the object even closer to your body. Then stand up from the squat position while at the same time pressing the object close to you. When you come back to standing, the item should be pressed firmly against your abdomen or chest depending on its size. Think of it like you’re lifting an infant. Handle with care!

Lifting Overhead

Let’s suppose you wanted to lift the item you picked up from the floor over your head (maybe to put this “baby” on a top shelf). You would change the position of the hands so that you are handling the object at the sides now. Then contract the core and axial stabilizers (see Part 1 for details on how to do this). Now you will need to squeeze the shoulder blades together and lift the object through your body and then through your arms. Once it’s at the desired height, place it gently where it needs to go. This can also be done with one hand if the object is light and small enough.


The act of pushing starts with the back foot. To start, you will do better by placing one foot in front of the other. Dig the balls of the toes of the back foot into the ground and push forward. Transfer that force through the hips, pelvis, core and axial stabilizers and move your shoulder blades forward in the direction you are pushing. The only thing left to do is finish the push with the arms, extending the elbows and keeping the hands flat against the object being pushed.


To pull, you still want one behind the other for better leverage. Grab the item with both hands, and bend your elbow and pull your shoulder blades together (scapular squeeze) while transmitting the weight of the object through your core and down into the feet. Keep your back upright or extended by engaging the axial stabilizers to avoid any back or neck injuries. Keep the elbows close to your torso to protect the rotator cuff from strains. A good movement to copy is rowing.


One of the more complex motions that is almost always done wrong by non-professionals. There are many ways to skin this cat, but here is one effective method. One foot goes in front of another. Like a push, start by pushing off with the back toes and pushing the force through the hips, core and axial stabilizers. Then, with the object in the hand, keep it as far back as you can and rotate the trunk while at the same time, pushing off with the back foot and moving the hand from back to front. The more the hand travels, and the higher the acceleration and velocity, the further and faster the object will travel. For the furthest distance, an angular velocity of 45 degrees from the surface on which your are standing will yield best results. This is employed by most javelin and shotput throwers. Once the object is released, you will have to decelerate your body, primarily by having the leading foot land on the floor and stop the forward momentum.


This concludes the Modern Human Engineering series. Now you know the basics of most human movements, or as I call it Body Mechanics. It’s very important to not only learn these concepts, but execute on a daily basis. By making these principles your operating system for all movement, you will not only preserve your body for the future, but you will be able to do more with less effort. You will be efficient in your motions and this ultimately will preserve your physiological capital. This is a great starting point by which you can now enjoy more of the things you do while at the same time learning new concepts. That ultimately keeps you young at heart, and able to perceive living in a different light; and with any luck, Find Your Truth.

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