정적 균형 능력이 노년층의 트레드밀 및 지면 보행 특성의 관련성: CoP 기반 분석

다국어 초록 (Multilingual Abstract)

The purpose of this study was to examine the associations between center of pressure
based static balance indices and gait characteristics during treadmill and overground
walking in older adults. Static balance was assessed under multiple standing conditions,
with the eye-closed condition used as the primary analytical condition, and the eyes-open
（EO） and eyes-closed （EC） conditions were analyzed to compare postural control under
normal visual input and reduced visual input. The associations of static balance indices
with overground gait performance, overground gait variability, and treadmill gait
performance were examined.
Forty community-dwelling older adults aged 65 years or older participated in this crosssectional study. After providing informed consent, participants completed body
composition assessment, overground walking assessment, static balance assessment,
treadmill walking assessment, and lower-limb muscle strength measurement. Static
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balance was quantified using CoP-derived variables, including root mean square （RMS）,
sway path （SP）, range （RANGE）, and mean velocity （MV） in the anteroposterior （AP） and
mediolateral （ML） directions. Overground gait variables were divided into mean
spatiotemporal variables and coefficient of variation （CV） variables, whereas treadmill gait
variables were analyzed as mean spatiotemporal performance variables. Multivariate
general linear models were used to examine the associations between static balance
indices and each gait variable set while controlling for height, gender, age, weight, percent
body fat, and knee extension strength.
The results showed that CoP-based static balance indices were selectively associated
with gait characteristics according to visual condition and walking environment. Under the
EO condition, RMS_AP was significantly associated with the overground gait mean variable
set and was selectively related to step length. However, no significant associations were
observed between EO static balance indices and overground gait variability or treadmill
gait performance. Under the EC condition, RMS_AP, RMS_ML, and RANGE_ML showed
significant multivariate associations with the overground gait mean variable set. However,
no static balance index was significantly associated with the overground gait variability
set. In contrast, clearer associations were observed for treadmill gait performance under
the EC condition. In particular, the mediolateral CoP indices SP_ML and MV_ML were
significantly associated with treadmill spatiotemporal variables, including gait cycle,
cadence, stride length, and step length. These associations remained significant after
adjustment for covariates, partially supporting the hypothesis that static balance indices
would be associated with treadmill gait performance after controlling for individual
characteristics.
These findings suggest that CoP-based static balance indices are not uniformly
associated with all gait characteristics, but are selectively related depending on visual
condition, walking environment, and outcome type. In particular, mediolateral postural
control under reduced visual input may serve as a candidate correlate of treadmill
spatiotemporal gait performance in community-dwelling older adults. Given the crosssectional design and the use of linear CoP indices, these findings should be interpreted as
evidence of candidate associations rather than determinants of treadmill gait performance.

목차 (Table of Contents)

• I. 서 론 1
• 1. 연구의 필요성 1
• 2. 연구의 목적 3
• 3. 연구의 가설 3
• 4. 용어의 정의 4
• II. 이론적 배경 7
• 1. 노화와 보행 기능 변화 7
• 2. 자세제어(postural control)와 정적 균형(static balance) 8
• 3. CoP 기반 정적 균형 평가 11
• 4. 트레드밀 보행의 특성과 지면 보행과의 차이 15
• 5. 보행 변수와 보행 안정성: 수행력(performance)과 가변성(variability) 16
• 6. 정적 균형과 트레드밀 보행 수행력의 관련성 18
• III. 연구 방법 20
• 1. 연구 참여자 20
• 2. 측정 장비 22
• 3. 실험 절차 24
• 4. 자료 처리 29
• IV. 연구 결과 32
• 1. 참가자의 신체적 특성 32
• 2. 정적 균형지표와 지면 보행 수행력의 관련성 33
• 3. 정적 균형지표와 지면 보행 가변성의 관련성 48
• 4. 정적 균형지표와 트레드밀 보행의 관련성 49
• V. 논의 56
• VI. 결론 63
• 참고문헌 64
• Abstract 68