What is AIS?

Active Isolated Stretching (AIS), developed by Aaron L. Mattes, MS., R.K.T., L.M.T., of Sarasota, Florida, is a gentle method of stretching specific (isolated) muscles while requiring the active participation of the person being stretched. Each stretch begins by defining the current range of motion (stretch point). The target muscle is then stretched beyond that range with a gentle assist continuing for only two seconds. The muscle is then returned to its original resting position. Typically, eight to ten repetitions are required. Results are noticeable and often radical.

How AIS works

AIS is based on solid science incorporating these two scientific laws:

Sherrington’s Law requires that muscles are paired and coordinated with each other by engaging one muscle group while releasing the opposite muscle group at the same time. This is referred to as Reciprocal Inhibition. Engaging a muscle actively requires neural input to the muscle being engaged while the opposite muscle is neurologically signaled to relax. For example, when bending at the elbow, the bicep is neurologically signaled to contract while the tricep is signaled to relax. Only a relaxed muscle can be stretched. It is not possible to stretch an engaged muscle. When a muscle is neurologically signaled to contract, it is the intention of the person to contract the muscle. A muscle will go further with intent (from the brain by way of the nerve) than it will by a passive movement. This means that one will increase range of motion with movement through intention.

Wolff’s Law, in layman’s terms, relates to the body’s protective mechanism so that one doesn’t overstretch a muscle or tendon.  Muscles and tendons have the ability to measure the amount of tension being applied.  When a muscle is stretched beyond stretch point for longer than two seconds, the muscles tighten up. This reaction is also known as the stretch reflex. Violating the stretch reflex can cause muscular and tendonous tears. Therefore, no stretch should be held for longer than two seconds.

The benefits of AIS

  • Decreases or eliminates pain
  • Increases blood flow
  • Facilitates healing
  • Increases flexibility or range of motion
  • Improves ease of movement
  • Increases elasticity of fascia (connective tissue)
  • Relieves both physical and mental stress
  • Rehabilitates injured muscles and tendons
  • Restructues scar tissue to become more functional
  • Helps prevent many surgeries
  • Increases lymphatic flow to decrease edema (swelling)
  • Helps prepare tissue pre-surgery
  • Reduces risk of injury and reinjury
  • Improves posture: head, shoulder, thoracic, and low back
  • Improves breathing
  • Improves athletic performance and conditioning
  • Eliminates pain and stiffness of many types of arthritis

AIS is widely used by today’s athletes, massage therapists, personal/athletic trainers, and professionals.

What can you expect when you schedule an AIS stretching session?

  • Comfortable, loose-fitting clothing should be worn or brought in so you can easily stretch.
  • The health history, which you have downloaded from this site, should be filled out and brought in so that it can be thoroughly reviewed before the session. If you have any injuries which required x-rays or MRIs, bring a copy of your doctor’s report. No need to bring in the actual x-ray or MRI.
  • Unlike massage, you will be an active participant in these sessions.
  • Based on your situation and which AIS protocol is used, a massage table, chair, or standing position may be utilized for your session.
  • A typical session lasts anywhere from one to two hours.

Links to more information about AIS: