eBooks 
In Thai Massage, the side lying position is an efficient position to massage pregnant women, elderly persons or people who have serious back pains and cannot lie for longer periods in the prone or supine position, or heavily overweight or obese people.
In such cases, a Thai Massage session given will almost exclusively be carried out with the person in the side position. Moreover, the massage will typically be a full body Thai Massage covering all parts of the body.
Video | More info here
Full body sequencing in the side-lying position differs somewhat from routines in other positions, such as when giving a full body massage in the supine and prone position.
Experience has shown us that the most efficient and most relaxing way (for both therapist and receiver) to carry out a Thai Massage in the side-lying position is to first finish one side of the receiver’s body, and then finish the other side.
That is, the receiver will first lie on one side of their body (either left or right side), while the masseur works from the feet to the head, and afterwards the receiver will turn to their other side, while the masseur starts again at the feet and massages until the head. As such, the therapist will finally have given a complete full body massage.
Keep in mind that a predefined sequence or working routine in Thai Massage is not a must-do at all; a therapist can always decide to carry out things differently, for many reasons, without losing the efficacy of a treatment.
In the case of the side-lying position, the therapist may, for instance, first start with the head, or perhaps with the back or belly, and so on. Nevertheless, in most cases, one will always finish all the work one side of the body to then work on the other side.
