Normative data of postural sway by using sway meter among young healthy adults

Background: Postural control involves controlling body’s position in space for dual purpose of stability and orientation. Postural stability or balance is defined as the ability to maintain the projected Center of motion (COM) within the limits of Base of Support (BOS). During quite stance there is a separate Center of Pressure (COP) under each foot. The net center of pressure lies between the feet and depend on each limb support. Normally no one stand erect, instead the body sways in small amount, mainly forward and backward. Thus quite stance is characterized by small amount of spontaneous postural sway. The device (sway meter) consists of inflexible 40 cm long rod with vertically mounted pen at its end. The rod was mounted 20 cm wide metal plate which will be fitted at the level of PSIS (Posterior superior iliac spine) over lower back region of participants by firm belt. A low tech Sway meter was designed to address the needs of clinicians and researchers with limited resources (e.g. no access to force plates or motion laboratories). It is a useful field test, as it is compact, lightweight, has short administration and data processing time. Unlike other lightweight and easily applied systems, such as accelerometers and gyroscopes, the Sway meter involves no electronics or computer processing. Aim and objectives: To study the normative data of postural sway by using sway meter among young healthy adults, to study the normative data of postural sway by using sway meter among young healthy adults with eye open and eye close, to study the normative data of postural sway by using sway meter compare with the normal values of the lord’s and Sherrington’s study. Material and methods: The subjects were instructed to keep their hand by their sides during standing. Subjects were informed about procedure before starting. Duration of each trial was 30 second. A starting point was marked on the graph paper. At end of the 30 seconds, the rod of the sway meter was taken away from the graph sheet. 5-10 seconds rest was given during trial, but they were not allowed to move away from the foot print. The procedure was repeated for each trial. A total of six trials were taken including, 3 trial with eyes opened and 3 for eyes closed. Maximum duration for all trial was 6-7 minutes and maximum deviation in 3 trials was taken for analysis. Results: In eye open condition, in anterior direction, total 60 (100%) subjects are had sway in 0.1 to 2 cm. In Posterior direction, total 60 (100%) subjects are had sway in 0.1 to 2 cm. In right lateral direction, total 59 (98%) subjects had sway in 0.1 to 2 cm; remaining 1 (2%) subject had sway in 2.1 to 3 cm. In left lateral direction, total 56 (95%) subjects had sway in 0.1 to 2 cm; remaining 2 (3%) subjects had 2.1 to 3 cm sway and 2 (2%) subjects had 3.1 to 4 cm sway in left side. In eye closed condition, in anterior direction 57 (95%) subjects had 0.1 to 2 cm sway in anteriorly, but remaining 2 (3%) subjects had 2.1 to 3 cm sway, and 1 (2%) subject had 3.1 to 4 cm sway. In posterior direction 59 (98%) subjects had 0.1 to 2 cm sway in posterior; rest 1 (2%) subject had nil sway in posterior. In right lateral direction 56 (93%) subjects had 0.1 to 2 cm sway, and rest of the 2 (4%) subjects had nil sway, and 2 (3%) had 2.1 to 3 cm sway in right direction. In left lateral direction 57 (95%) subjects had 0.1 to 2 cm sway, and 1 (2%) subjects had nil sway, rest 2 (3%) subjects had sway in 2.1 to 3 cm. Conclusion: It has been concluded that this study support the self constructed sway meter as a clinical tool for identifying sways in various directions (anterior, posterior, right lateral and left lateral). Similarly 100% of sway was seen in anterior and posterior direction with eye open.