First, let's review the shape of the spine. The spine has four curves. 1) the cervical curve (neck) goes in 2) the thoracic (mid- back) curves out 3) the lumbar (low-back) curves in 4) the sacrum curves out. The shape of the spine and how much curve each section of the spine has depends on several things, including the body type, any congenital defects (i.e.) scoliosis, their developmental activities (i.e.) did they practice gymnastics or ballet as children, and what are their functional activities now (i.e) do they play racket sports, golf, or have an occupation that requires a repetitive action like a factory assembly line.

The reason I start with this information is because what may look like a flat back or reverse thoracic curve on one person may be quite normal in another. Ex. if a young woman is born with an ectomorph (vata) body type; thin and long boned, and then she practices ballet as a child and continues into adult hood, she may well appear to have a flat back, her spinal curves will have almost disappeared. This is not a defect or dysfunction for her. It is a body type and the result of years of a specific developmental activity. So, be sure that the student who comes to you and announces that they have an inward or reverse thoracic curve has been diagnosed by qualified professional.

Nothing exists in a vacuum. If the thoracic spine is flat it has an effect on other parts of the spine and the muscles that shape it. Usually the flat thoracic spine will be accompanied by a posterior tilt of the pelvis and a flattening of the lumbar spine. The posterior pelvic tilt will present with tight hamstrings, hip extensors and weakened hip flexor muscles. Slight knee flexion may be found with this posture due to the tight hamstrings.

From the reflex therapy point of view, the leg reflects the back turned upside down. The Achilles tendon reflects the neck, the calf muscles reflect the upper back, the hamstrings reflect the low back.

So the strategy for the legs and the hips is to release the calf and hamstring muscles and strengthen the hip flexors. Some techniques for this strategy are:

Virasana (kneeling) with a rolled up mat or a pole between the calf muscles and the hamstrings. This is quite painful when the calf muscles are tight. Start with the rolled up mat and gradually progress to a rigid pole.

For strengthening the hip flexors practice Utthita Hasta Padangusthasana (standing hand to extended big toe pose) hold the leg up using the Psoas muscle and keep the standing leg straight and the pelvis from tilting.

For the thoracic spine itself remember that the baby balances (Bakasana, Tolasana & Lolasana) move the thoracic spine back. If the full classic posture is to difficult for your student to practice, this is where the creative use of props comes in. Use blocks or chairs or any other variation to achieve your intention: to round the upper back.

The most important thing for your student to be aware of is how they practice forward bends. The neutral position of the foot in seated forward bends is very important due to the reflex therapy reflection of the leg and back. Observe the shape of Mr. Iyengar's feet in seated forward bends in "Light on Yoga". The soles of the feet are not perpendicular with the floor. They are at an angle of approximately 45". This is to reduce strain in the calf muscles and maintain correct alignment in the knees. The basic instruction in forward bends is to lengthen the front spine. This is because most people have a thoracic curve that is excessive and in a forward bend they looked humped in the middle and upper back. If the pelvis does not tilt forward they risk strain of the lumbar by trying to get lower into the pose. Your student must work the action of tilting the pelvis forward intensely using the hip-flexors, primarily the Psoas. The action of lengthening the front spine must be practiced not so intensely. When holding the forward bend it might help to meditate on the Anahata (heart) chakra. Use the color green and/or the bija mantra Yam (pronounced yung).

If the student is more advanced the Halasana and its variations can be of great benefit. Also look at Plate #260 in "Light on Yoga" and read what Mr. Iyengar writes about the backward movement of the spine in Setu Bandha Sarvangasana.