procedure
Randomization
The 36 patients who met the above inclusion criteria were randomly assigned to either the treatment (TTM) group or the control group using block randomized allocation with block size of 2, 4, and 6. Groups were assigned using a pre-generated random assignment scheme enclosed in envelopes (STATA Version 9), Which resulted in a total of 18 patients per group.
treatment
Treatment group (traditional Thai massage-TTM)
participants received one 30-min session of TTM onto the back muscled while lying in the prone position during the period between 10.00 and 13.00 h on the day of the study. Based on the experience of the first three authors who work as both physiotherapists and massage therapists, plus the outcome of the pilot study, a 30-min session was considered appropriate for an effective impact of massage when confined to the back area only.
All TTM in this study was conducted by a well-trained massage therapist, according to the system of royal Thai massage, which applies the theory of "Sen Sib" or the 10 meridian lines. Massage points included in this method are located along two lines and at an additional, single, point along the paravertebral muscles on each side of the spine (Chatchawan et al., 2005). The two lines on the left side of participants are called Ittha and the two lines on the right side of participants are called Pingkhala (The massage points, along the two meridian lines running from thoraco-cervical junction or C7 to posterior superior iliac spine). The pressing technique employed in TTM uses the body weight of the massage therapist to apply gentle, gradually increasing, pressure through the therapist's thumb, fingers, or palm. Pressure is applied until the patient starts to feel slight discomfort after which this pressure is maintained for 5-10 s at a time. This sequence can be repeated several times for each massage point (Chatchawan et al., 2005).