Position for Exercise Execution◆ ☕️ 6 min read
Position, in the simplest terms, is the location where something has been put. In the biomechanics realm, we can define it as the starting place of the axial skeleton and pelvis. Position is what sets the foundation for the movement of the body.
The human skeleton can be split into two – the axial and appendicular skeleton. The axial skeleton consists of the bones of the cranium (skull), the vertebral column (spine) and the rib cage. The appendicular skeleton is mainly concerned with limbs, the shoulder girdle and the pelvis.
In the sports industry as a whole, it is common to get lost in the way the limbs move, without actually paying attention to the foundation of that movement - the position. Before we can become overly concerned with what is happening in the appendicular skeleton, we need to make sure the axial skeleton positioning is appropriate to allow for the expression of movement.
Whereas this may sound confusing, we can look at it from the perspective of a single joint. A joint, by definition, is a point in the human body where bones meet. As such, it is necessary to consider both the distal (further from the center of the body) and proximal (closer to the center of the body) structures that make that joint. It is inadequate to just focus on one. The structures at both ends of a joint are dynamic and capable of triplanar motion.
For example, when discussing anything in regard to shoulder movement, we often turn to the humerus as the primary concern. What about the position of the scapula that impacts the motion of the humerus, alongside the position of the ribcage affecting the position of the scapula? We can’t simplify those things down to just one structure. It has to be looked at as a whole.
A doorframe analogy is often used to illustrate the concept. The position of the doorframe itself allows for the motion of the door to occur. If we change the position of the doorframe we will impact the motion of the door.
If we want to move the lower limb, we can’t just focus on the femur but have to consider the position of the acetabulum on the pelvis, which is the socket in which the femur sits to form the hip joint.
If we want to move the upper limb, we can’t turn all attention to the humerus, but have to look at the scapula and subsequently the ribcage too, as the scapula sits on it.
If we don’t look at the whole picture from the beginning, it is easy to perform movements with sub-optimal positioning, leading to more and more wear and tear as the motion is repeated in such a way.
Sure, that’s an approach that is built on health. Performance and health are not the same. Performance requires more specificity, which can have a negative impact on health. Health is more about variability and building resilience.
For a powerlifter, whose performance is dependent on how much they can lift, you will let them bench press with a back arch that will allow them to press the most weight. Specificity is required. This is probably not the best set up for health in terms of the position, as an excessive extension pattern is reinforced with the ribs flared and pelvis in an anterior tilt. But it’s a position that will allow for more weight to be lifted. Performance is king.
Still, you would look to tick the box of variability with the accessory work to ensure longevity. The powerlifter might be doing a variety of accessory pressing motions, like incline bench and dumbbell press variations. This is probably a better place to enforce proper axial skeleton positioning in which an alignment is achieved between the skull, ribcage, and pelvis, often called “stacking” the ribs over the pelvis or a “stacked" position.
This is really the key foundational position needed for expressing movement. Diverging from that will alter length-tension relationships of muscles. This will affect the muscles’ ability to produce force. Muscles produce force optimally at their resting length. This means they are not excessively lengthened or shortened, but exist in that “mid” range. This comes back to the mechanics of muscle contraction and the cross-bridge cycle. When a muscle is too eccentrically lengthened, there is not enough overlapping between the actin and myosin filaments for the muscle to effectively contract. Contrary, at a very short position, the overlapping of those filaments is already excessive, thus no further overlap can occur, and force production ability is reduced.
Individuals that exist in either orientation pattern extremes, be it in an excessively shortened or extensively lengthened state of a muscle, tend to have limited movement capabilities. Individuals with a more “neutral” muscle orientations existing in the “mid” range have better ability to utilize either the shortened (concentric) or lengthened (eccentric) orientations when appropriate as dictated by the task.
Coming back to that bench press example, if we anteriorly rotate the pelvis, extend the spine, and elevate the ribcage in the front, we might reduce the range of motion needed to bench press, which will allow us to bench more weight, but we are changing our movement strategy through which this is achieved. A position like this will change the length-tension relationship of the muscles that attach to those structures. Our intelligent nervous system will then rely more on the recruitment of the muscles that are more strongly positioned and less on those which are poorly positioned for the given movement. If you excessively rely on a sub-optimal movement strategy in your exercise execution and continuously enforce it, you will build up the muscles that are in more preferred positions and less those that are in poor positions. The long-term consequences of such behavior don’t require much imagination.
Coming back to the powerlifter example, and comparing that to a general population client, who might be all about improving their health, you don’t need to chase the numbers at all if it’s not important to them. In this case you’re probably better off focusing on position from the start and maintaining or fixing the length-tension relationships, making sure the muscles fire as they are intended to fire when met with a specific movement requirement. In a bench press example, this might be a more flat-back approach to pressing, where the ribs and pelvis are properly aligned.
This is also a reason why I’m not a huge advocate for the “mind-muscle connection” concept, even though there is some evidence for that. It’s just a wrong thing to focus on. What’s the use of actively focusing on contracting a specific muscle when your positioning is all messed up? Put the muscles in positions in which they are intended to work in, and they will work.
The same concept applies to most professional athletes. Why would you let them sacrifice on their positioning to potentially reach a higher 1 repetition maximum? If they are not in a weight lifting sport, their performance is not dependent on how much they can lift. They are making their money elsewhere. As such, they are far better off getting the position right for longevity purposes and potential injury risk management. You don’t want to repetitively work those sub-optimal mechanics. Overuse injuries don’t exist. These are misuse injuries. Fix the position and you will avoid a lot of problems further down the road.
Now this is not to say that you should hold off anyone from loading an exercise until you have hammered in every tiny detail of technical execution and positioning into them. You’ll just need to make sure you are getting what you are intending to get out of an exercise. If loading compromises the goal, adjustments need to be made.
Ultimately, task demands and individual goals determine how movements are best executed. But the awareness of positioning is key for the expression of motion and thus long-term health.