How Does Flexibility Relate to Range of Motion and What’s the Difference?

 Most forms of stretching define flexibility as range of motion - or a muscle getting long. On the one hand, we at Bendable Body agree - you do want to be able to move fully in your body and you do want your muscles to get long. On the other hand, that is only part of the picture. So what exactly is flexibility verses range of motion? And how do they compare? Let's find out. 

Muscles don't just get long... they also shorten (contract) and twist. Their ability to make all of these movements is true flexibility combined with strength... and they go hand and hand.

The true test of muscle strength and flexibility isn't how long it will get, but rather how short it will get. A muscle can only lengthen in direct proportion to the amount it can shorten. True flexibility is the ability to maximally contract or "flex" your muscles through a range of motion.

When you passively lengthen a muscle without maximally contracting it, these 3 things go wrong:

1. Micro tears form in the muscle. Your body's immune system responds to this by patching up the tears with fascia.

2. You are training your muscle to stay over-stretched and weak... and to not contract and be strong like it is designed to do.

3. You are over-stretching your ligaments and tendons and forcing biomechanical substitutions in your joints to achieve the range of motion.

When you continue to lengthen beyond a muscle's natural capacity to contract, you are exceeding your range of motion and over stretching. However, stretching with resistance increases your ability to contract with more and more force (strength) through greater and greater ranges of motion (flexibility).

Examples of over-stretching:

A. Hyper-extending knees to produce range in inside and back leg muscles.

B. Hyper-flexing ribs to raise arms and produce rotation in shoulders.

Improved flexibility gives you more energy, mobility and improves posture.

Developing true flexibility improves muscle strength, avoids and repairs cell and tissue damage, allows for stable, easy movement, and gets rid of joint pain. When you are truly flexible, it means your muscles can move your body with ease. This takes less energy than when they have to move in and through unhealthy fascia - or redirect movements elsewhere to insufficient patterns. 

When you lengthen a muscle - produce a range of motion - you should also be able to contract or shorten that muscle proportionately. A prefect example is someone who can do wide leg splits and put their chest on the floor with ease. If this capacity were true flexibility, they would also be able to use those same muscles that are lengthened in the splits to pull their legs back together to a standing position. They can't and instead use their arms and other muscles to get out of the split position. They therefore do not have true flexibility but instead have a 'false range of motion' that has most likely been established through years of end range stretching in the ligaments and tendons. 

John demonstrates flexibility verses range of motion and when you are in the 'danger zone' of overstretching: 

Try this stretching exercise for an increase in both flexibility and range of motion: 

  1. Do 3 sets of 8-10 repetitions on the right leg only (take a few second break in between each set). 
  2. Before switching to the left leg, stand up and try a forward bend with your feet a little wider than shoulder width and your knees slightly bent. 
  3. Notice how you can fold or 'shorten' easier in the front of the hip on the right side verses the left. Also notice how you have less strain in the hamstrings on the back of the right leg compared to the left. 
  4. This stretch is for the hip flexors (the front of the thigh and hip). You got an increase in flexibility in the hip flexors demonstrated in the easier fold on the right side of your body verses the left after only stretching the right leg. You also got an increase in range of motion in the hamstrings (which you did not stretch) because the balancing muscle group (the hip flexors) got more flexible.  
  5. Now do the left leg and feel the same result. 

Pillar 1 - Start Position: Hand on front of target leg and other hand behind stabilizer knee. 

Pillar 2 - Resist: Draw knee into the chest and press stabilizer leg into other hand. 

Pillar 3 - Lengthen for the Stretch with resistance throughout the movement: Using hand to press leg away. 

Pillar 4 - Release and Return to the Start position. Repeat Pillar 1. 

4 thoughts on “How Does Flexibility Relate to Range of Motion and What’s the Difference?”

  1. Wow! I am surprised at the difference in the hip flexors after I did the 2 leg tests! Amazing! I do sitt for long amounts of time…so I will be more aware to get up every 15 mins to stand now! Thank you for explaining each exercise thoroughly!

    1. I am so thrilled you got a result! I hope you keep stretching with us. For lots of sitting its so important to stretch your hamstrings!

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