Introduction
Our body has muscles to enable movement. With this, we have the freedom to move away from danger or come closer to rewards – locomotion. Locomotion can require more or less force, and it is on this occasion that strength comes into place. With more strength, we can overcome more stressful movement-related challenges. Climbing, running, jumping, throwing, and other movement patterns had occurred in our prehistoric setting. However, due to huge changes in production, we have built a physically less demanding environment. While this is highly beneficial to our society, we have reduced our physical stress to such a low level that it leads to detrimental side effects on our physical strength. For that reason, we now need to replicate this core movement patterns and overload them, in order to make us stronger and healthier.
Targeting muscles through their movement function
One of the most efficient measures to improve our life quality is Exercising [3]. With Exercise, we aim to make our muscles stronger. We achieve that by seeking muscular fatigue. This, in turn, causes positive changes, resulting in an overall improvement in life quality [2]–[4].
We target muscles through movement patterns
To fatigue muscles as efficiently as possible, we need to apply the correct Exercise form [5]. The first point of proper Exercise form is the movement pattern. Each muscle controls a specific limb’s movement. Muscular contractions power the movement. Repeated and intense muscular contractions eventually lead to muscular fatigue.
The more involved a muscle is in a movement pattern, the faster it fatigues. So to make our muscles efficient, we need first to find the correct movement patterns.
Types of skeletal muscles
While all skeletal muscles help movement via muscular contractions, their functions differ. Some muscles are located near the bones and joints, while others are found beneath our skin. The first group of muscles is called deep stabilizer muscles, while the latter is called the superficial muscles.
Stabilizer muscles stabilize the joint
Stabilizer muscles, also known as local muscles, are located near the bones and joints. Their muscle fiber type is mostly Type 1, which means that they fatigue at a slower rate and can produce less force. Finally, stabilizer muscles can modulate joint stiffness. For that reason, they serve as joint stabilizers and not prime movers [6]. Fatiguing a stabilizer muscle should not need a lot of external load or resistance. If it does, you are likely using superficial muscles instead of stabilizers. Stabilizer muscles are always active when performing exercises for the major superficial muscles. Thus, it is not essential to fatigue stabilizer muscles in isolation. A sign of fatiguing stabilizers is shaking the limbs when executing a movement pattern.
Most known stabilizer muscle groups
- rotator cuff muscles
- deep muscles of the lower back
- hip stabilizer muscles
- deeper muscles of the abdominal wall
Superficial muscles overcome force demands
Superficial or global muscles are the primary initiators of movement. Movement is possible by generating the torque required for joint motion. The superficial muscles are close to our skin and have more Type 2 or fast-twitch muscle fibers [7]. Because of that, they are intended for load-bearing and have a more significant potential for size. Fatiguing superficial muscles need heavier resistance. When our superficial muscles are fatigued, our speed of movement slows down.
Major superficial muscle groups
- neck
- shoulders
- chest
- arms
- forearms
- upper back
- middle back
- lower back
- abdominal
- hips
- legs
- calves
Many muscles, few movement patterns
With Exercise, we want to improve all the major muscles in our body. There are, yet, more than 150 muscles available. The amount of work and time required to fatigue them all in isolation would be enormous. Involving an exercise with synergistic activation of many muscles is a more productive approach [8, Ch. Muscle isolation]. And in that regard, the number of movements required to hit most of our major muscle groups is drastically reduced.
Muscles that are close together fire together
In a movement pattern, muscles are involved based on proximity. Those muscles being close to each other, are also engaged in similar movements. The more a muscle is distant from another, the less likely it will be involved together in an activity. For that reason, we usually split our muscles into a few categories to denote their proximity. For instance, when we do a movement involving our arms, muscles of the upper body will be mainly engaged. On the other hand, when we move our legs, muscles of the lower body will be engaged.
Agonist and antagonist muscles
Another important categorization of muscle is the agonist and antagonist. In many movements, some muscles contract while others lengthen simultaneously. The agonist is the flexing or active muscle, while the antagonist is the relaxing muscle. For instance, both muscles of the upper arms, triceps, and biceps are involved in the movement of the forearm. However, when we do bicep curls (elbow flexion), the bicep flexes as the triceps lengthens. With triceps extensions (elbow extension), we are doing the opposite. It is the triceps that contract and the biceps that lengthen. It is the contracting muscles that fatigue and improves.
Transverse plane - Separating muscles of the upper and lower body
The first split happens in the vertical direction at our hip:
- upper body
- lower body.
For most of the muscles in the lower body, we can do exercises that avoid the involvement of the upper body and vice versa. So this split is the most rudimentary. As stated earlier, movement of the arms (in any direction) will involve muscles of the upper body. The movement of the legs on the other side will include muscles in the lower body. Nonetheless, lower back and abdominal muscles can be intensely involved in upper and lower body action.
Muscular synergy
As stated in the section above, we have many muscles. But, muscles rarely act in isolation. Instead, they cooperate to produce a movement involving many joint rotations and multi-joint exercises. Multi-joint exercises fatigue and improves several muscles at once, drastically improving productivity. However, not all multi-joint movements are appropriate to establish profound muscular fatigue.
Some multi-joint movements involve disjoint movements. The reason is that the muscles are not working together to achieve a single motion. They work separately to do a subpart of the whole motion. An example of that is a squat and press motion in one exercise.
Improve efficiency by using synergistic multi-joint movements
A movement like a Squat and press is an example of a wrong multi-joint movement. It involves a shoulder press and a squat. Yet, these movements are disjoint, i.e., the shoulder muscles do not help with the squatting, and the leg muscles do not help with the shoulder pressing.
Contrastingly, movements like a pull-up involve synergistic activity of multiple muscles. Muscles include trapezoids, latisimuss dorsi, rhomboids, biceps, and forearms. All of the muscles involved pulling together to complete the movement of a pull-up.
Sagittal plane - Separating Muscles of the torso and the muscles of the back
The second split is in the sagittal plane: frontal and dorsal aspects of the body. However, due to design, the lower body muscles cant be detached from each other in a similar manner, then the torso muscles can. For this reason, the split in the sagittal plain will focus on the torso muscles only.
The torso pushes away, and the back pulls towards
We have the front torso or the pushing muscles, and in the back, we have the pulling muscles. Pushing muscles work together to move an object away from our bodies, whereas pulling muscles do the opposite. They draw an object closer to it. We count the chest, shoulders, and triceps for pushing muscles. For pulling, we count the muscles of the latisimuss dorsi, trapezoids, rhomboids, biceps, and forearms. Every single muscle in the chain handles a specific movement. Yet, using the principle of synergy, we can involve them all with one movement.
The joint angle influences the involvement of a particular muscle
Pushing and pulling exercises can be performed at different angles. And the angle will highlight the engagement level of a specific muscle in the chain.
In the upper body, most of the movement happens around the shoulder joint. For instance, in a chest press, the angle of the shoulder joint is at 90°. This puts the chest muscles opposite the direction of the resistance. Therefore, these muscles will take on the grunt of the load. On the other hand, the shoulders are opposite resistance at 180° of shoulder flexion – shoulder press. For that reason, the shoulder muscles carry more load in that exercise.
Upper body movement patterns
As noted before, we separate upper body movements into pulling and pushing exercises. Using different angles, we can develop many variations of pulling and pushing movement patterns. The angle change comes by changing the angle of our shoulder joint. There are many variations, between 0 – 180°. However, there are three shoulder joint angles that differ the most:
- shoulder at 0° (dip, upright row).
- shoulder at 90° (chest press, row)
- shoulder at 180° (shoulder press, ching up)
| Exercise name | Pushing or pulling | Primary muscles | Secundary muscles | Terciary muscles |
|---|---|---|---|---|
|
Up-right row |
Pulling |
upper trapezious, lateral deltoid |
biceps, forearms |
neck, latisimuss dorsi, rhomboids |
|
Dip |
Pushing |
chest, front (anterior) deltoids |
triceps |
lower trapezious, latisimuss dorsi |
|
Horizontal row |
Pulling |
middle trapezious, latisimuss dorsi, rhomboids, rear (posterior) deltoids |
biceps, forearms |
lower back |
|
Chest press |
Pushing |
chest, front (anterior) deltoid |
triceps |
lower trapezious, abdominals |
|
Chin-up |
Pulling |
latisimuss dorsi, middle and lower trapezious |
biceps, forearms, rhomboids, rear (posterior) deltoids |
abdominals |
|
Shoulder press |
Pushing |
front (anterior) and side (lateral) deltoid |
chest, triceps |
neck, upper trapezious, lower back, abdominals |
Lower body movement patterns
Compared to the upper body, the lower body involves fewer movement patterns. It’s all because the lower body’s significant muscles (glutes, thighs, and hamstrings) are attached to the hip. Any movement of the hip will therefore engage all of these muscles. In principle, a single movement – a squat – involves all of the major muscles of the lower body. Yet, the location of the resistance influences the engagement of each muscle. We placed the resistance close to our knees and shifted the load to the rear. This we call a hinging motion (a deadlift). In contrast, we call a squatting motion (a front squat) to set the position close to our glutes. It then shifts the load more towards the thigh muscles.
| Exercise name | Squatting or hinging | Primary muscles | Secundary muscles | Terciary muscles |
|---|---|---|---|---|
|
Front Squat |
Squating |
quadriceps, glutes |
hamstrings |
calves, lower back |
|
Stiff legged deadlift |
Hinging |
glutes, hamstrings, abdominals |
calves, lower back |
quadriceps |
|
Trap bar deadlift |
Hinging |
quadriceps, glutes |
hamstrings, lower back |
calves |
Conclusion
This post has gone through the most basic and efficient motor activity we can use to boost our muscle engagement. We have first described the difference between the stabilizer and superficial muscles. While stabilizer muscles are vital, they can be improved by only working on the vital superficial muscles. Secondly, we have proposed a minimalistic approach to efficiently grouping muscles for enhanced efficiency. We have divided our bodies into two planes: transverse and sagittal. With the transverse plane, we distinguish between upper and lower body movements. We can differ between the back and front muscles with the sagittal plane. The four basic movements by combining these two planes are defined. These basic movements are pulling, pushing, squatting, and hinging. These four motions are the foundation of effective and safe exercise. Finally, adding some diversity by changing joint angles adds a level of insurance that all body muscles are fatigued adequately.
