Short-term relationships between footstep variables in young adults.

Autocorrelation analyses were used to quantify the short-term relationships between selected footstep variables during steady state, straight-line over-ground walking in 20 healthy young adults. The serial dependency for step length, step time, heel to heel base of support (HHBS) and double limb support time were examined for a minimum of six consecutive steps using an 8.3m GAITRite analysis system. As well as investigating the dependence of data obtained from consecutive steps (lag 1) and between steps of consecutive strides (lag 2), cross correlation analyses were used to explore the relationships between step length and HHBS. The results showed serial dependency from one step to the next for step length and step time, whereas HHBS and double limb support duration showed stride-to-stride autocorrelations. Cross correlational analyses did not reveal a relationship between stride length and HHBS, suggesting independence between these variables.