Understanding Mobility vs Flexibility

There is often confusion surrounding the difference between mobility and flexibility, but the distinction is simpler than many people think.

Let's start with a basic definition of each:

Mobility is your ability to actively move and control your body through a range of motion. In other words, it is the range of motion you can actually use.

Flexibility is the passive range of motion available at a joint or within a muscle. This range is often achieved with the help of gravity, an external force, or assistance.

Our goal is typically to improve mobility—becoming stronger, more capable, and more comfortable in our movement. However, if there is insufficient passive range of motion available, flexibility may need to be addressed first. Once adequate range exists, strength and control must be developed within that range to truly make it usable.

Let's break it down:

Mobility	Flexibility
Active, usable range of motion	Passive range of motion
Requires strength and control	Does not necessarily require strength or control
Improves movement capacity	Improves movement potential
Helps build resilience throughout a range	Increases available range
Focuses on owning a position	Focuses on accessing a position

Below are three examples that, when performed in sequence, can help develop not only greater flexibility, but also the strength and control required for lasting mobility.

Bent-Knee Hamstring Stretch with PAILs

This exercise is designed to improve hamstring flexibility while building strength and control in your newly acquired range of motion.

Setup

• Sit on a yoga block with one leg extended in front of you and a slight bend in the knee.

• Keep your chest lifted and your spine long.

• Think about reaching your chest forward rather than rounding your back.

• You should feel a gentle stretch along the back of the thigh.

Perform

1. Hold the stretch for 30 seconds.

2. Press your heel into the floor as if trying to drag it backward for 30 seconds.

3. Relax and move deeper into the stretch for another 30 seconds.

Prescription: 2 - 3 sets

Passive Range Lift-Off (PRLO)

A Passive Range Lift-Off helps develop active mobility and teaches the nervous system to create movement rather than simply tolerate a stretch.

Setup

• Brace yourself using the bent leg.

• Lean forward until lifting the straight leg becomes challenging.

Perform

• Without moving your torso, lift the straight leg off the floor.

• Slowly lower it back down with control.

• The movement should feel effortful.

Prescription: 8–12 repetitions, 2–4 sets

Passive Range Hold (PRH)

A Passive Range Hold helps improve strength at end range and increases your ability to actively control positions that are often only accessible passively.

Perform

• Pull the leg toward you until you feel a stretch along the back of the thigh.

• Attempt to hold the position actively.

• Let go with your hands while maintaining the position.

Hold: 5–10 seconds

Sets: 3–5 repetitions per side

Remember, flexibility is only part of the equation. Lasting mobility comes from developing strength and control within the ranges you gain.