Stomach Massage and Inversion of the Lumbar Curve
This exercise, done in a rounded position with the head toward the pelvis, exerts pressure, generated by the flexion, on the lower trunk. This series has several variations, but this effect is most notable in the rounded version.
Principles of the Exercise
These four movements are done in succession.
1. The feet press against the bar to extend the knees and the hips. This moves the carriage backward. The feet are pointed (ankles in plantar flexion).
2. Then, with the knees straight, the ankles are flexed (dorsiflexion) and the heels pass under the bar. The carriage slides forward a bit.
3. The feet are then pointed again and the carriage moves backward slightly.
4. The hips and knees are then flexed, which brings the carriage back to starting position.
If this exercise is done correctly, the lumbar spine should be stable and able to maintain its natural curve (slightly arched).
When this exercise is being executed, or even in the starting position, the lumbar curve will often disappear. The pelvis tips into retroversion causing flexion of the lumbar spine.
Why? Because of hamstring tension.
How and Why
The Impact on the Lumbar Spine
The retroversion of the pelvis, caused by the pull of the hamstrings, in turn promotes flexion of the lumbar spine. This flexion isn’t harmful in and of itself, but it takes place under pressure. Where does the pressure come from?
- In part, because of the load (the lumbar vertebrae are supporting the weight of the upper trunk). Warning: this is a very loaded position when the trunk and head are flexed over the legs.
- In part, because the pelvic retroversion is caused by permanently tight hamstrings. And this occurs in a very specific context: the hamstrings are stretched, but they also contract, and this happens at the same time that we are moving the carriage in and out against spring resistance.
So, during flexion, the vertebrae are caught between two opposing forces and this can cause disc compression.
Spinal flexion compresses the discs. We look specifically at what this action does to the disc’s nucleus.
Flexion Pushes the Nucleus to the Back
If the yo-yoing of the pelvis causes “scissoring” of the annulus, prolonged compression of the lumbar discs when the spine is in flexion pushes the nucleus posteriorly.
Vertebral Ligament and Sciatic Nerve
Pushing the nucleus posteriorly is much riskier than pushing it anteriorly, especially if the disk is already fragile, because in this area of the spinal column we find a ligament and components of the nervous system--in particular the sciatic nerve.
- If the nucleus has already broken through the annulus (and this rupture is usually posterior), this is called a herniated disc.
- If the compression of the disc or the annulus puts pressure on the posterior ligaments, they can become overtaxed and painful. This can be a dull or a sharp pain and we call it lumbago.
- This compression can also irritate the nerve and this is referred to as sciatica.
All of these conditions--herniated disc, lumbago, and sciatica--can exist simultaneously.
Solutions and Prevention
How to Maintain the Integrity of the Vertebral Discs
1. Evaluate and Relax the Hamstrings
The best way to prepare for this exercise is to know just how tight the hamstrings are by sitting on the floor with the legs straight in front of you. If you can maintain the lumbar curve even with the knees extended, you can probably perform this exercise without difficulty. However, in most cases, the hamstrings are too short and tight and the lumbar spine rounds. If this is the case, it’s best to “prepare” the hamstrings with an exercise independent of, and prior to, Stomach Massage.
It’s beneficial to lie on the back when stretching the hamstrings. Keep one foot on the floor, knee bent, and lift the other leg--bent if necessary. Place a band around the raised foot. Try to bring the coccyx to the floor and the heel toward the ceiling at the same time while gradually extending the knee.
2. Stretch the Hamstrings on the Reformer
Lie down on the carriage with the feet in the straps, straighten the legs to a 45 degree angle, legs slightly turned out and heels connected. Bring the legs to vertical while keeping the pelvis stable and the ischia parallel to the carriage. When the hamstrings are tight, this variation of Frog allows you to stretch to your threshold and then gradually move beyond it as you progressively work to bring the legs to vertical. Don’t focus on the 90 degree angle, but work to find a better range of motion. You can also use the roller and small balls to stretch the muscles and fascia.
3. Modify the Exercise
Before doing the round back variation of Stomach Massage, you can choose one of the variations in which the back is kept in alignment. The arms and hands are placed behind you, which allows you to find the support you need to keep the spine straight. Once this step is mastered, you can progress to the full exercise. You can also place a ball between the shoulder blades and the low back to support the lumbar spine.
4. Open the Ribs
As in Teaser, opening the ribs lessens the descent of the viscera mass and “lifts” the trunk. However, this doesn’t lessen the pressure on the discs very much.
5. Reduce the Number of Springs or Their Strength
We can reduce the force of the springs while being aware that there needs to be at least minimal resistance, because without opposition the exercise will be too difficult to execute. Another option is to lower the bar, or, simply eliminate the exercise if it is too problematic.