Written By Harrison Pham on July 12, 2023

Stiff joints and/or the inability to move a certain way are often misunderstood as only an issue with flexibility. However, it is not that simple. Stiffness and limited movement may also stem from mobility restrictions such as muscle imbalances, joint-limb mechanics, and dysfunctional movement patterns. As a result, a common misconception is that stretching alone can address these issues which may exacerbate the issue. 

For example, those suffering from over-flexibility may develop joint instability from excessive stretching. This drastically increases the risk of injury; “ligaments [will] tear when stretched more than 6% of their normal length” (Bradford D. Appleton)

So What's the Difference?

So that begs the question… what is the difference between mobility and flexibility? Mobility refers to the ability to actively move both the muscle and joint through its full range of motion. In contrast, flexibility refers to the ability to move a muscle passively through its full range of motion. 

• Bad Mobility, Good Flexibility:  A gymnast is seen warming up and is able to bring their leg well over their head when stretching against the wall. However, it is visibly noticed that the gymnast can not do this motion without assistance during their routines.

• Good Mobility, Bad Flexibility: A lifter is able to lift a barbell overhead in a controlled manner. However, it appears that their elbows are not fully extended. This is because their shoulder is very stiff.

• Good Mobility, Good Flexibility: A martial artist can perform high kicks with ease without any assistance.

Understanding the difference between mobility and flexibility allows individuals to address specific limitations accordingly through training and corrective exercise. This is especially important for those who participate in sports, physical labor, or those who participate in physical activities that require complex movements and/or repetitive motions. By prioritizing both mobility and flexibility, individuals can enhance their quality of life and athletes can improve their performance in their respective sports.

TL;DR: 

Mobility and flexibility are not the same things. While flexibility refers to the passive ability to move a muscle through its full range of motion, mobility encompasses the active movement of both muscles and joints. Stiffness and limited range of motion can stem from mobility restrictions, not just flexibility issues. Understanding this distinction helps individuals address specific limitations through targeted training and corrective exercise. Prioritizing both mobility and flexibility is crucial for athletes, individuals engaged in physical activities, and anyone seeking to improve their quality of life.

Reputable Sources on Mobility and Flexibility:

• • Dr. Aaron Horschig (Squat University)

    • https://squatuniversity.com/

    • https://www.youtube.com/@SquatUniversity

  • Dane Miller

    • https://www.garagestrength.com/

    • https://www.youtube.com/@GarageStrength

  • “The Kneesovertoesguy”

    • https://www.atgonlinecoaching.com

    • https://www.youtube.com/@TheKneesovertoesguy

References:

• • https://beaconphysicaltherapy.com/whats-the-difference-between-flexibility-and-mobility/#:~:text=Mobility%20is%20dynamic%20or%20active,help%20of%20the%20other%20hand.

  • https://web.mit.edu/tkd/stretch/stretching_3.html