Flexibility VS Mobility

In this blog I will share the definitions that are found in scientific research in the hopes that it will clear up any confusion about what you are doing in your training. The meanings behind our words is important, our whole language and understanding is based on semantics, so yes, lets be picky!

What is flexibility?

Flexibility is a component of fitness that describes the biomechical movement at one or more joints. Flexibility is a physiological movement (something that can be voluntarily performed) and can be measured in multiple ways. The easiest, and most popular method, being the measurement of range of motion.

Flexibility is just one of the components of fitness that can be performed by the human body. The other components are: strength, endurance, speed, coordination and agility. These are all motor abilities and, therefore, contribute to the overall movement of the human body.

What are the types of flexibility?

Dynamic Active
is any movement completed within your own voluntary effort that moves through ranges.
Dynamic Passive
is being moved through range by someone else, whilst you are relaxed, by a therapist or stretch partner.
Static Active
is engaging a muscle in to the end range, without movement occurring.
Static Passive
is being held in a position by yourself or someone else, whilst you are relaxed.

What is stretching?

“Any exercise that stretches the muscle fibers with the aim of increasing flexibility and range of motion” (PUBMED definition).
There are 4 types of flexibility, so very simply, there must be 4 types of stretching. I have added a couple of examples of each, to help you understand the differences and see how popular stretching methods fit in to these 4 categories:
Dynamic Active
e.g leg swings in to a high kick, controlled articular rotations (CARS), ballistic.
Dynamic Passive
e.g being moved through a range of flexibility by someone else
Static Active
e.g isometric holds, PNF, PAILS/RAILS, MET, contract/relax… it is all the same really, I find it’s just easier to call it a static active stretch!
Static Passive
e.g sitting in the splits or basically relaxing in any stretched position.

What is mobility?

There are 2 types of mobility that are described in scientific literature.

Accessory mobility (joint mobility)
“Joint mobilization refers to a technique of manual therapy by which a therapist applies a brief pressure through traction and gliding along a joint surface.” (Science Direct Definition)

Accessory mobilisations are movements within the joint itself and is not a movement that can be isolated without the help of an external force. It involves manually moving the bony parts of the joint and only creates a very small movement that is felt rather than seen. Accessory movements are often achieved by a therapist, such as mobilisations and manipulations, or through exercises that use specific equipment, for example, banded hip distractions.

The easiest way to measure accessory (or joint) mobility is by assessing the “end feel” of the joint, which is something that can be assessed by a therapist, or possibly a coach, if they are trained.Joint mobility is often confused with flexibility but hopefully this helps you see a very clear difference. Flexibility, can be seen, whereas, joint mobility is a deep movement between 2 bony segments of a joint and can’t be seen in normal movement. However, if accessory movement is dysfunctional, then it can affect your overall physiological movement, including flexibility.

Global mobility
“Mobility is the ability to navigate through space independently, safely and efficiently.” (PUBMED definition).

Global mobility refers to the overall capacity of functional movement. This is affected by each of the motor abilities: strength, flexibility, endurance, speed, coordination and agility. All of these need to be developed to have overall quality of functional movement capacity.

As referred to in research, mobility exercises help improve someone’s quality of daily living, standing up, walking etc. Mobility is not measured by range of movement, rather by how well you can perform day to day tasks without support. Think about ‘mobility tools’ these help people go about their daily life, for example, walking sticks. However, for someone of ‘normal’ function and ability, their mobility can be measured by how developed all their motor abilities are and, therefore, how developed their overall functional movement capacity is. Examples of higher level global mobility exercises include squats, pull ups, chin ups and press ups which improve various components of fitness, including flexibility.

Why does it matter?

These terms are used in the majority of scientific research and by using them it keeps instruction evidence based and avoids confusion for clients and patients.

If you want to know more about this concept brought to our attention by Dan Van Zandt, who has an in depth knowledge of scientific research, then check out his Instagram or this brilliant podcast where Dan goes in to a lot of detail about this concept.

If you have any questions on this topic, feel free to contact me! Kassia x
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