Mobility versus flexibility- what’s the difference?

If you’ve spent any time exercising or even doing housework, you have experienced the importance of mobility without even realizing it. You were able to reach for the weights on the machine because you have mobility in your shoulder. Or you were able to squat and kneel to clean the floor because you have mobility in your hips, knees, and ankles.

Mobility is simply the coordinated movement of a joint to allow us to move through a range of motion. Flexibility on the other hand is the passive lengthening of a muscle. More specifically, flexibility does not require input from the brain.

Mobility is not as simple as being able to bend over and touch your toes.

Every joint in the body has a normal range of motion (ROM). For example, a normal knee will go from 0 degrees (all the way straight) to 150 degrees (all the way bent). Having flexibility means that your muscles allow whichever joints they cross to move through that full ROM, passively. In the example of the knee, having flexible quadriceps means that the muscles on the front of the thigh are not too tight that they limit you from bending your knee to the full 150 degrees.

But there is so much more that goes into having full ROM than just flexibility.

This is where mobility comes in.

Mobility requires muscle flexibility, joint mechanics and motion, strength, and motor control.

Think of a car.

If all it had were wheels and a frame, it would move on its own if you put it on the right hill. That would be flexibility in this case. The car needs brakes, an engine, gas, and a steering wheel to safely and efficiently move. That would be mobility.

Good mobility can prevent injury and improve performance.

Typically, the body will find a way to perform a movement even if it is lacking the proper mobility to make it happen. This is where injuries happen. Compensation will occur in another joint to make up for the lack that of mobility.

Let’s break down a deep squat to understand where mobility comes in.

A deep squat requires adequate range of motion at the hips, knees, and ankles, motor control (brain to muscle connection) in the quads and glutes, and core strength. If the person performing the deep squat is lacking mobility at any of those joints, you’ll typically see excess movement in the lower back, shifting to one side, caving in of the knees, and much more.

Mobility exercises are not one size fits all.

Each person has different needs based on their usual activities. Physical therapists will use functional movement screens, gait and running analysis, and postural assessments to determine areas that might need extra attention.

About the Author:

Dr. Walter is a Doctor of Physical Therapy with an emphasis on treatment of spinal conditions. She graduated from Saint Louis University in 2014 with her Doctorate of Physical Therapy and completed undergraduate work at the same institution. From 2018 to 2019, she was a post-graduate resident with the McKenzie Institute. There she achieved certification in the McKenzie Method of Mechanical Diagnosis and Therapy (MDT) and board certification in orthopaedics (OCS). Chelsea enjoys working with clients who are active in the gym or with recreational sports. She has led an active lifestyle from early on in life and enjoys hiking, travel, and spending time with family.