Active Isolated Stretching (AIS) is based on a sound scientific principle known as Sherington’s law of reciprocal inhibition. Simply put, that the muscle on one side of a joint must relax in order for the opposing muscle to contract. Keep this in mind and I’ll explain the difference between AIS and typical stretching. With AIS you contract the opposite muscle of the one you want to stretch and you hold it for only 2 seconds and then lower to the resting position. With typical stretching, the stretch is held from 5 seconds up to a minute. The problem with a prolonged stretch is muscles have a protective mechanism called the stretch reflex; after approximately 3 seconds, the muscle you’re trying to stretch contracts in order to protect itself from being overstretched. A contracted muscle cannot be properly stretched; moreover, this form of stretching is damaging, ineffective, and actually removes oxygen from the tissue. AIS uses reciprocal inhibition to its advantage, the relaxed muscle is stretched for only 2 seconds; this avoids triggering the stretch reflex. These gentle stretches are done in multiple reps of up to 10 times. Using AIS safely elongates muscle and fascia; as a result, blood rich in oxygen, nutrients and lymph is delivered to the tissue.
Using this technique, the muscles exhibit a greater range of motion over the course of each set of stretching repeat. You will see fast improvements in flexibility.
The muscle is coaxed through its last few degrees of motion either by a partner, or more commonly, by the use of a band or rope that is wrapped around the foot or leg in various ways depending on the direction of the stretch.
Make an appointment with Jen Kunio LMT, CSCS to learn AIS hands on.