Dynamic Postural Balance: Neck Motion and Center of Foot Pressure.

Objective: To study neck proprioceptors for dynamic postural balance, head motion and center of foot pressure (COP) were recorded simultaneously during the motion of head or chest. Materials and Methods: Seven volunteers with no neurological diseases participated in this study. Head motion was monitored with accelerometers and autogyros on the head, and COP was monitored on a force platform. The subject was standing upright on the platform with eyes immobilized and the subject was asked to rotate the only head alternatively repetitively or to rotate the chest and head synchronized. Both the motions were asked to rotate at own pace, quick pace, slow pace, and 0.5 Hz pace for 20 sec, respectively. Results: The frequency of the motion with the head only showed higher than that of the motion with the chest and head synchronized (P < 0.0001), and the frequency was significant among pacing (P < 0.000 1). The wave powers of the head motion during the motion with the head only were larger than those with the chest and head synchronized (P = 0.0011). The wave powers of COP oscillation during the motion with the chest and head synchronized were larger than those during the motion with the head only (P = 0.0027). The cross powers during the motion with the chest and head synchronized were larger than those with the head only, between the head motion and COP oscillation (P = 0.0154). Conclusion: Neck motion is important to stabilize postural balance on turning around, neck motion might provide us much information for dynamic examination of COP. [ABSTRACT FROM AUTHOR]