Functional stretching is stretching which prepares the joints and muscles for the demands of sport...prepares them to be lengthened in all three planes(tri-planar) of motion or directions of movement (sagittal: front to back, frontal: side to side and transverse: rotational); maximizing your ability to move athletically.
How does it work?
1-Three dimensional lengthening: As noted above , the joints move and the muscles lengthen three dimensionally when we walk, run, jump etc. Therefore, applying this knowledge of biomechanics to stretching, it becomes quite obvious that to fully lengthen/stretch a muscle to prepare for athletic activity, the stretch needs to be performed three dimensionally.
2- Foot on the ground stretching: For most athletic activity, the foot is on the ground and the body moves over the foot. Preparing the muscles for this weight bearing activity should therefore be performed in the same manner. Performing stretching exercises in the lying or sitting position does not replicate the joint motion of the body driving over the foot as it does when we walk , run, and jump.
3. Multiple joints training simultaneously: During athletic activity , the foot, ankle, knee, and hip all move as a symphony-coordinated motion with all the joints moving three dimensionally all at the same time. Functional stretching replicates this multi-joint motion. Many of our leg muscles cross more than one joint therefore what motion is happening at each joint is critical to achieving full stretching/lengthening of the muscle.
For more information on three dimensional training, click here.