| 제목 |
Posturography parameters in patients with the history of ankle sprain – a pilot study |
| 소속 |
CHA Bundang Medical Center, CHA University School of Medicine, Department of Rehabilitation Medicine1, CHA University, Rehabilitation and Regeneration Research Center2 |
| 저자 |
Joonhyun Park1*, Woo Kyung Park1, Hyun Seok Kwak1, Mi Ri Suh1,2, Kyunghoon Min1,2† |
Introduction
The ankle is the most common area for a ligament injury. Previous ankle sprain is associated with a 2.3-fold greater recurrence. Chronic ankle instability is characterized by recurrent ankle sprain and leads to the sensation of “giving way” suggesting decline in balance ability. The posturography is a technique that measures balance in certain postures. In this study, we aimed to reveal the pattern of balance parameters in patients with the history of ankle sprain through the posturography.
Method
From the database of our institute between 2014 and 2018, patients who were diagnosed with ankle sprain were extracted. Among them, those who underwent the posturography test were included. Patients with known neurological disorders were excluded. Data was collected by the static posturography device Tetrax® (Sunlight Medical Ltd) in 8 standardized positions. One sample t-test was done to compare each parameters to known mean values. Statistical analysis was done with SPSS (IBM, version 21).
Results
A total of 10 patients were included for the analysis. First, by comparing the results at the basic posture (normal eyes open, NO) with known normal reference value, we found significant differences in Fourier index (FI) of frequency ranges F2, F5 and F6 (Table 1). The stability index (ST) and weight distribution index (WDI) were also significantly different from the normal mean values. The Fourier Power spectrum (Figure 1) shows the FIs of low frequency (F1) and high frequency (F7-8) are reduced compared to normal profile while FIs of the medium frequency (F2-4 and F5-6) take up more portion. When defining values less than -1 or greater than 1.5 standard deviations from the average as abnormal cases, F2-4 results were all abnormal in postures with the position change of head in 7 out of 10 patients. At head lateral tilting postures, the synchronized indices (SI) were abnormal in 27.8% of total cases. Compared to SI in other postures, SI in head tilting posture appeared to have higher sensitivity (Figure 2).
Conclusion
In this study, several posturography abnormalities were observed in patients with the history of ankle sprain. The medium-frequency FI was sensitive in assessing overall ankle instability, while SI was sensitive in assessing balance decline caused by unilateral ankle instability. Further study with larger number of patients will be necessary to develop more accurate indicator for assessing chronic ankle instability.
|
|
Table 1. Parameters of posturography comparing the patients and normal group in basic posture
Figure 1. The Fourier Power spectrum of postural sway pattern (at normal eyes open position)
Figure 2. Percentage of abnormal posturography parameters in different postures (n = 10)
|
