"Stabilise then mobilise" - quite the oxymoron to get your head around in the throes of four point kneeling.
But, in actual fact, stability and mobility are inextricably linked. Stabilising and controlling particular areas of the body effectively allows for optimum mobilisation and recruitment of other, desired parts of the body.
Stability (when combined with correct alignment and if appropriately utilised), should facilitate the correct and indeed most effective type, range and sequence of joint movement. It should assist at a specific moment, in the correct direction and at an appropriate level of exertion for the task.
Stability should also prevent undesirable movement patterns from occurring, thus limiting the potential for injury or strain. For example, in “Hip Rolls”, the spine is mobilised by rotation, but physical (and mental) effort must be made to stabilise and avoid unwanted movements such as flexion ( forward movement of the spine), lateral flexion (sideways movement) or extension (backwards movement of the spine) which could compromise the lower lumbar area. So whilst the spine is being “mobilised” and rotated sequentially, it is simultaneously being “stabilised” and controlled to avoid movement into other incorrect planes. Stability is provided in this example (and in general) by having a centred ‘core.’ But this is more than just the active recruitment of the abdominals which control, almost counterbalance the potential for unwanted movements. It's about maintaining control, not stillness, of the positions of the other critical areas of the body; the pelvis, the spine, shoulders and head. Indeed it is these aforementioned areas, the ‘centre’ which provides the fundamental platform and support basis from which all movements in pilates are initiated. This is known as core stability.
Whilst stability happens at a deep subconscious level, effective awareness and recruitment of the stabilising process should also be encouraged at a conscious level (mind/body connection), together with the importance of good alignment and effective breathing. Breathing itself provides a stabilising effect, whereby upon inhalation, the diaphragm contracts, increasing abdominal pressure and consequently a more stable structure (intra cavity pressure) around the abdominal region is provided, as well as the pelvis, lumbar, ribcage and thoracic spine. This stability must be maintained during the exhalation process through active contraction of the abdominal muscles. Interestingly most pilates exercises utilise the out breath for which to conduct/commence their movement highlighting the importance of starting from the bodies strongest, most stable platform.
As a Pilates student, you'll grow to become much more aware of the importance and benefits of the stabilising process, how your overall recruitment patterns, posture and movement can and should evolve and hopefully change for the better. You'll begin to feel how mobility is best controlled and most optimally conducted when it works synergistically with stability. It acts in a number of different ways in the body, subconsciously through a variety of passive and active systems and at a conscious level where an appreciation of correct alignment, breath and centring can be effectively utilised /instilled to allow the the body is able to move more efficiently. This results in more effective/positive changes being made on the mat and hopefully - consequently, functionally applied into your everyday movement.
In essence, with stability we have more powerful, reliable and effective mobility. It transforms all movement for the better.