For those of you not familiar with the Kinstretch system, Kinstretch is a movement enhancement system that develops maximum body control, flexibility, and usable ranges of motion.

Kinstretch has many components, each with different functionality, but all leading us to the same goal – active mobility.

For example, Controlled Articular Rotations (CARs) are a maintenance and assessment tool.  Many people think that CARs will help improve their range and solve a host of issues, but in reality this is not true.

CARs are extremely powerful in maintaining joint health, current ranges of motion, and serve as an assessment tool, but expansion of range of motion is reserved for PAILs and RAILs.

PAILs stand for Progressive Angular Isometric Loading.  These are isometric muscle contractions that strengthen the muscles placed on stretch.  If your hip was flexed (knees to chest), the progressive tissue would be the glutes and hamstrings.

RAILs stand for Regressive Angular Isometric Loading.  These are isometric muscle contractions that strengthen the muscles on the closing side of the joint.  If your hip was flexed, the regressive tissues would be your hip flexors and quads.

When To Use:

PAILs and RAILs contractions are used whenever we see limitations in movement.  Limitations in joint movement can happen from disuse, postural demands placed on the body, or due to injury.

In the case of injury, PAILs and RAILs should NOT be used.  These contractions should always be pain free, and can do more harm than good if the tissue is not ready for this level of stress being placed on it. PAILs and RAILs are most appropriate when we find muscular/joint restrictions in an area of the body.

They help expand motion in two ways.

  1. They help teach the body that your end range of motion is safe.  By driving a limb into an object and creating a strong muscular contraction – your nervous system realizes that the position is actually safe to be in.  This then allows your RAILs contraction to allow you pull yourself into a deeper stretch, thus starting to expand your ranges.
  1. The muscle contractions on both sides of the joint help strengthen the end ranges, allowing them to become acquired actively over time.

If you were to only work the side of the joint that feels the stretch, you wouldn’t necessarily improve your mobility.  This is because muscles not only need to learn to lengthen, but shorten as well.  So RAILs contractions become just as important as PAILs.

Implementing In Your Practice

PAILs and RAILs contractions can easily be used within any of your base positions to help make the position easier to sit in, improve a limited range of motion at a joint, or help smooth out transitions with your isometric movement paths.

Secondly, don’t be afraid to explore your Controlled Articular Rotations afterwards.  They can serve as a pre-post test to see if what you did made a change to your mobility.  This will also give your nervous system the opportunity to explore and conquer the new ranges of motion you worked so hard to get during your personal practice.

Remember, in your Kinstretch practice PAILs and RAILs are our primary tool to expand range of motion.  All other end range options help build more neuromuscular control.

Happy Moving!

Written By:

Joe Gambino, PT, DPT, CSCS
FRCms , FR Practitioner, Kinstretch Certified Instructor