What is the difference between flexibility and mobility?

What is the difference between flexibility and mobility?

To me they seem the same so wondering if anyone can explain the difference?

Hi Anthony,

Being flexible means that you have a good range of motion, and is more about the length of the muscle. Mobility however, is being able to control your range of motion. In order to build good mobility you will need both the passive flexibility and strength to control your movements through your range  

Flexibility refers to the length of a muscle. Mobility is the range of a joint.   

So is flexibility a subset of mobility? Meaning mobility includes both lengthening as well as shortening the muscle (contraction)? And that too with resistance?

There is a synergy between the two. For instance a tight bicep, will prevent full extension of the elbow.  Also a stiff joint ( through disuse or injury) can cause the surrounding muscles to weaken and become tight or "shorter".    

And I would like to change my definition of flexibility to "the pliability of a muscle". When a muscle become more supple and more pliable, it is easier to stretch, but that doesn't mean it has become 'longer'. 

Hi Anthony,

The difference is quite simple actually.

- flexibility is 'passive' range of motion.  Passive means strength is not exhibited; e.g. supine shoulder extension stretch.

- mobility is 'active' range of motion.  Active means that strength is exhibited; e.g. standing weighted shoulder extension pulls.

Yours in Fitness,

Coach Sommer