The influence of the thoracic spine is very important in more than just the exercises I mentioned in Part I. As a general rule: if an exercise requires good scapular mechanics, then the t-spine must be in a good position to support the scapulae.
The "cart" and "track" analogy is commonly used to describe the relationship between the femur and patella to patellofemoral pain. As a reminder, how much good is fixing the "cart" when the "track" is broke? How much good are we doing working on scapular stability is the t-spine isn't in a good position for the scapulae to glide along it?
During any kind of row or push up, the t-spine must be extended for the athletes to be able to retract and depress their scapulae. Instead, if the t-spine is stuck in too much flexion, the rounded rib cage will literally guide the scapulae into elevation and an anterior tilted position. This is typically described as upper trap or lev scap dominance. That may be true..but that also may NOT be a cause (of shoulder and neck problems) in itself, but a result of poor t-spine function.
The t-spine is very real and very important regardless of the athletes you are training, and the exercises they are performing.