Final answer:
The general direction of massage movements on the abdomen should follow the orientation of the abdominal muscles: inferiorly and medially for the external oblique, superiorly and medially for the internal oblique, and horizontally for the transversus abdominis.
Step-by-step explanation:
When working on the abdomen during a massage, the general direction of the massage movements should correspond to the orientation of the abdominal muscles. The external oblique muscles, which are the most superficial, extend inferiorly and medially, much like sliding your four fingers into your pockets. Therefore, massage movements in this area should follow this direction. The internal oblique muscles are located perpendicular to the external obliques and extend superiorly and medially, mimicking the direction your thumbs would go when your other fingers are in your pockets. Movements here should follow suit. For the deep transversus abdominis muscles that wrap around the abdomen like a belt, the massage movements should be transverse, moving horizontally across the abdomen. This approach helps to align with the natural fiber orientation of the muscles for effective muscle manipulation and facilitates circulation.