Background: Deficits of both ankle dorsiflexion range of motion (DFROM) and dynamic balance are shown in persons with chronic ankle instability and the elderly, with the risk of falls. Objects: This study aims to investigate the relationship between DFROM and dynamic balance in elderly subjects and young adults. Methods: Fifty-nine subjects were divided into three groups: ankle stability young group (SY), ankle instability young group (IY) and ankle stability older group (SO). We recruited three old subjects with ankle instability, but excluded them during a pilot testing due to the safety issue. DFROM was measured by weight bearing lunge test (WBLT) and dynamic balance was measured via star excursion balance test (SEBT) in anteromedial, medial, and posteromedial directions. The group differences in WBLT and SEBT and each group’s correlation between WBLT and SEBT were detected using the R statistical software package. Results: The dorsiflexion range of motion was significantly different between the SY, IY, and SO groups. The SO group showed the highest DFROM and IY group showed the lowest DFROM (SY: 45.88±.66˚, IY: 39.53±1.63˚, SO: 47.94±.50˚; p<.001). However, the SO group showed the lowest dynamic balance score for all SEBT directions (SY: 87.24±2.05 ㎝, IY: 83.20±1.30 ㎝, SO: 77.23±2.07 ㎝; p<.05) and there was no relationship between the dorsiflexion range of motion and dynamic balance in any group. Conclusion: Our findings suggest that ankle DFROM is not a crucial factor for dynamic stability regardless of aging and ankle instability. Other factors such as muscle strength or movement coordination should be considered for training dynamic balance. Therefore, we need to establish the rehabilitation process by measuring and treating ROM, balance, and muscle strength when treating young adults with and without ankle instability as well as elderly people.

본 연구에서는 지진계 센서의 동적범위를 향상시키는 새로운 방법을 제안하였다. 먼저, 센서에 포함된 저주파수 대역 잡음을 ARMA(Auto Regresive Moving Average) 모델로 모델링하고 시스템 식별 방법으로 그 모델을 식별한다. 다음으로, 모델링된 잡음과 지진파 입력을 칼만필터 식에 포함하여 칼만필터에 의한 지진파입력을 추정한다. 제안한 방법을 새로이 개발된 MEMS 기반 3축 가속도 형태의 지진계에 적용하여 성능을 검증하였다. 시험 결과는 제안한 방법이 단순한 LPF(Low Pass Filter)를 사용한 경우에 비해 동적범위를 개선시킴을 보여준다.