Flexibility, like any other form of training, should follow a systematic progression. This is known as the flexibility continuum. There are three phases of flexibility training: Corrective, Active and Functional.
Corrective flexibility is designed to improve muscle imbalances and altered joint motion. It includes static stretching and self-myofascial release (SMFR). This is the beginning of the flexibility continuum.
The next progression is Active flexibility. Active flexibility is designed to improve the extensibility of soft tissue and increase neuromuscular efficiency. It allows for cooperating muscle groups (agonists and synergists) to move a limb through a full range of motion while the functional muscles (antagonists) are being stretched. This progressive phase includes SMFR and Active-isolated stretching.
The final progression is Functional flexibility. Functional flexibility is integrated, multiplanar soft tissue extensibility, with optimum neuromuscular control, through a full range of motion. Essentially, it is movement without compensations. Functional flexibility uses dynamic stretching and SMFR.
Dynamic stretching uses the force production of a muscle and the body's momentum to take a joint through the full available range of motion to improve soft tissue extensibility. Dynamic stretching is used as a pre-activity warm-up, formed as 1 set of 10 reps for 3-10 different exercises. Medicine ball rotations and walking lunges are good examples of dynamic stretching.
By training in an integrated, systematic fashion, you'll achieve optimum results in an efficient manner. You'll maximize your results without increasing the risk of injury, leaving you sitting on the sidelines.