The walking stability becomes less stable under the influence of a problematic posture or back. This problem was analyzed on the basis of two new approaches. The first approach is a newly developed measurement system, consisting of two accelerometers for walking analysis. It was a small, wearable, micro PC-assisted portable system. However, it was difficult to analyze directly the characteristics of movement stability using the raw measurement data. The second approach was an analysis of impulse response using AR modeling. Once it was understood standing with correct posture, the fluctuation of subject's both sides of the hip while walking was improved more rhythmic in the female students. The analysis of impulse response, utilizing AR modeling, provided clear results for the evaluation of improvement to walking stability.