My yoga teacher tries to get us to do twists involving the thoracic spine while not twisting the lumbar and cervical spine. Is this possible?

Yes, it is possible to isolate the thoracic spine from the lumbar and cervical spines during a twist. To do this, you must first establish proper alignment of the spine to ensure that each vertebral segment remains secure. Start by engaging your core muscles. Then draw your navel towards your spine as if you are doing an abdominal crunch so that your lower back does not over-arch.

Next, notice where on the floor each side of your pelvis touches when in a seated position. This will help you keep equal weight in both sitting bones while creating stability throughout all three sections of your spinal column: cervical, thoracic and lumbar segments.

Now initiate a twist by rotating through either hip joint—not the waist—which helps to create length along both sides of your spine as one continuous unit rather than segmenting it into its separate parts (cervical/thoracic/lumbar). As you rotate, imagine drawing energy up from deep within each hip joint into the rib cage and eventually reaching above between shoulder blades and simultaneously below at pubic bone level; essentially connecting these two ends with every slow and conscious turn of this movement practice.

Finally remember that tightness existed in all three sections before we even began twisting—curls inwards for instance making for more rounded shoulders or slouching forwards leaning chin down towards chest etc.. Pay close attention to noticing any changes throughout entire body as you hold here allowing time for active relaxation moving away from tension held prior to twisting spine deeply yet cautiously without going too far beyond healthy range of motion!