PURPOSE:
- Strengthen abdominals.
- Strengthen back extensor muscles (especially in flat back).
- Stretch the low back (especially in round back).
- Learn balanced strength between front of the body (abdominals) and back of the body (back extensors).

SPRINGS:
- All the springs: carriage doesn't move.

EXERCISE VARIATIONS IN VIDEO:
- Round back
- Rotation
- Around the World
- Flat back