Method
15 healthy persons who were pain-free and didn't have the history of neuromuscular disease were participated in this study. Measurements were taken in three different sitting positions (relaxed, erect and forward head posture) with staring forward and arms hanging at the side. Paraspinal myoelectrical activities were measured by surface electrodes in paracervical, paralumbar, sternocleidomastoid (SCM) and levator scapular (LS) muscles. Simultaneously whole spine lateral X-ray including skull was taken. We measured cranio-cervical spinal alignment indicies (craniovertical, craniocervical, cervicohorizontal and upper cervical angles) introduced by Huggare and Gonzalez, lower cervical angle, lumbar lordosis angle and myoelectrical activity of each muscle in three different sitting positions.

Results
The analysis of relationship between lumbar lordosis and cranio-cervical spinal alignment index showed significant results. The more the lumbar lordosis increased, the head forward displacement decreased. But, the myoelectrical activities of paraspinal muscles were not influenced by the posture.

Conclusion
Maintaining lumbar lordosis is very important to correct forward head posture and research for the distraction force loaded to soft tissue of the neck in forward head posture is needed. (J Korean Acad Rehab Med 2003; 27: 126-130)