Whether we are treating neck pain, frozen shoulder, sciatica or helping an athlete improve their performance, we always start with stability. Failure to be stable is at the root of most every joint issue.
So what exactly is stability? Every time we move, certain groups of muscles will contract to pull our bones in a certain direction. We call these 'Extrinsic' (or prime mover) muscles. If we only had these muscles working, the joints would literally get pulled apart. Thankfully there are actually another group of 'Intrinsic' (or stabilising) muscles that work at the same time to hold the joint together yet still allowing it to move. It is essential that both muscle groups are working at the same time.
So what goes wrong? Trauma is the biggest factor. The high forces from trauma can have lasting effects particularly on these intrinsic muscles, leaving them less able to contract strongly. Since the intrinsic muscles are not under conscious control, it is very difficult to do an exercise to turn them back on. Adjusting to Neutral very specifically re-calibrates and balances these intrinsic muscles. This will get your spine stable very quickly.
Once the spine is stable, it is much easier to improve strength and flexibility of the joint. In most cases where the spine stability is not resolved, it will be very difficult to make any significant gains in strength, stability or endurance of function.
There is obviously a lot to how this process works and the precise details are explained in a video on my YouTube channel if you would like to know more.