In current study, the acceleration RMS of COM was
directly derived from COM displacement data, while usually
trunk acceleration is registered by the accelerometer and its
stride-to-stride variability is assessed by autocorrelation
procedure [9, 10]. This reflects possible difference in the age
effect on the body acceleration and its variability: Our older
adults showed a greater variability in ML direction, while no
different variability in AP direction during level walking.
Moe-Nilssen et.al found that less able subjects performed
reduced ML variability and increased AP variability [13]. It
needs further investigations to decide the acceleration of