Strength is a skill (Part 1): The role of motor patterns in strength

Our Central Nervous System (CNS) is responsible for coordinating action within and between muscles. A specific sequence of those actions is called a motor pattern. Improving proficiency within those motor patterns leads to:

• Improved muscle recruitment

• Better force transfer

• Efficient use of energy

In this two-part blog series, I discuss what these motor patterns are and how they relate to strength output (Part 1) and I will discuss also how this knowledge can be used for building strength (Part 2). If you’re interested in learning more about how I apply this, please feel free to reach out.

Strength

We often think of strength as simply being the result of a muscle contraction. And in that line of thought, we also associate strength training with increasing our muscle mass. While this is partially true, under the hood a lot more is going on.

To a large degree, our ability to express strength depends on our proficiency to fully use our muscles to generate force and create the optimal positions to transfer that force. Our Central Nervous System (CNS) is responsible for this and plays a crucial role in the process of strength expression. Improving the efficiency of our CNS is a phenomenal tool to increase strength, especially for those that want to build strength without gaining weight.

Central Nervous System (CNS) & Motor Patterns

Amongst other tasks, CNS is responsible for the contraction of individual muscles, intermuscular coordination, but also the orchestration of those contractions between different muscles, intramuscular coordination.

Simply speaking, intramuscular coordination determines how much of a muscle’s true capacity is recruited and how well it functions. Our muscles are controlled by a large number of motor units that each control a small part of the muscle. The CNS is responsible for recruiting these motor units. The proficiency of the CNS at using a muscle is determined by elements like the number of motor units activated, the recruitment speed and rate, and the synchronisation of contractions between motor units. These elements determine how much of the full potential of a muscle is used. The better our CNS is at this recruitment process the more proficient we are in generating strength.

Another factor that influences our production of strength is our (lack of) ability to coordinate the contractions between different muscles during a task. This is called intermuscular coordination. In seemingly simple motions a large number of muscle contractions and relaxations have to take place for the motion to be executed and the right joint angles to be created. Such a sequence of different muscle actions along with the intermuscular processes that subsequently happen is called a motor pattern.

Let’s look at a simplified example of an arm curl. Before the movement starts, muscles in the wrist, lower arm, and shoulder isometrically contract to stabilize the arm and prevent it from rotating and moving in unwanted directions. Then the agonist, the biceps brachii and brachialis, contract concentrically to initiate movement. The antagonist or the opposing muscle must relax to allow the agonist to do its work. Which in this case is the Triceps brachii. Even though this is a highly simplified example of a motor pattern the complexity already shows. Now picture such a motion being executed in a dynamic and high-speed environment. As you can imagine, the motor pattern becomes very complex, very quickly.

When looking at the quality of a motor pattern there three main considerations:

1. Are the joints at the right alignment to create optimal stability, force generation and force transmission?

To produce maximal force our joints need to be at the right angle for muscles to produce optimal strength. Muscles are stronger at certain lengths than at others. Additionally, proper alignment of the other body parts must be achieved to ensure proper force transmission. Proper alignment assures that there are no “energy leaks” and all the force is transmitted in the right direction.

2. Are the muscles involved acting at or close to their full potential?

The more proficient one becomes in certain positions and movements, the better the CNS becomes at recruiting the different muscles involved. Additionally, our brain’s ability to ignore or overwrite inhibitory impulses is an important factor in expressing strength. Inhibitory impulses diminish the force output of a muscle and therefore don’t allow us to use them to their full capacity.

3. Is the person moving smoothly and efficiently through the motor pattern with the right order of movement, spending as little energy as possible?

This last point results to a large degree from the first point with smooth and efficient movement being a result of minimizing energy leakage. However, having the right firing pattern is a unique and crucial ability. This means that joints and muscles move in the right sequence and are mainly loaded at the angles at which they are strongest. A good example is the lumbopelvic rhythm that describes the sequence of bending forward. Which should ideally be initiated from the upper part of the spine followed by movement in the hips. Deviation from this pattern has been found to lead to strength reduction and injury.

Additionally, when it comes to orchestration of movement. We should realize that the ability to relax a muscle is a crucial part of a proficient motor pattern. Not being able to relax antagonists counteracts the output of the agonist results in a waste of energy and a decreased force output.

When the optimal combination between these factors is established, an athlete can both produce and transfer force optimally, therefore, utilizing his capabilities to the fullest. This not only leads to optimal top-end strength production but also contributes to endurance. In which the economic use and transfers of force are crucial.

When comparing two athletes with the same force output, the one with the most optimal motor patterns has to spend less energy to achieve the same output and can therefore sustain a certain output for a longer duration.

How to increase skill in a motor pattern?

Motor patterns are highly trainable even though the activation of a motor pattern mostly happens subconsciously. Simply speaking, our body tends to choose the easiest way of accomplishing a task as long as it is familiar with the execution. The more familiar it is with a certain sequence the higher the likelihood that that sequence will be used and the better and more coordinated the body is in its execution. So, by consciously executing the right motor patterns we can teach our body how to move efficiently. This is called positive reinforcement of the neural pathways responsible for that pattern. There are some very interesting and highly effective ways of including positive reinforcement in our training.

For practical ways to improve motor patterns stay tuned for the next blog