Functional range of motion is an important part of any fitness routine. Proper flexibility improves performance and helps to prevent injuries to muscles, tendons and joints. Stretches may be broadly classified as active or passive. Properly applied, both types are effective.
In active stretching, muscles on the opposite side of the joint or body are contracted concentrically (shortened), to create lengthening in the muscle group that needs to be stretched. Neurologically, we are incapable of contracting and shortening on both sides of a joint simultaneously. For example, to stretch the hamstrings (back of the thigh), the quadriceps and hip flexors (front of thigh and body) are contracted.
The fully stretched position should be held for no more than 2 seconds. The movement is repeated to build up time in the stretched position, leading to increased flexibility. Active isolated stretching principles can be applied to any area of the body.