Differences in gait dynamic stability of healthy subjects due to age, body mass, height, BMI, and walking speed

Gait deformities are usually assessed by comparing patients' data with healthy subjects. However, the variability among healthy subjects due to age, body mass, height, BMI, and walking speed could influence the baseline data and hence rehabilitation measurements. Recent studies reported gait variability among healthy subjects considering age as a variant. The independent effect of other variants such as body mass, height, BMI, and walking speed on variability in the baseline data has remained unknown, hence investigated in this study. The centre of pressure signals collected from 205 male subjects was categorised for each of the mentioned five variants. Gait variability was evaluated in terms of walking stability. The centre of pressure signals was analysed by applying Nyquist and Bode methods to compute walking stability during the gait loading and unloading phases. A statistical comparison (one-way ANOVA, p < 0.05) revealed significant variability in the baseline data for variables (age, height, walking speed) during the loading phase and in the anterior-posterior direction. In the medial-lateral direction, these differences were observed as significant during both loading (age, body mass, speed) and unloading phases (age, body mass, height). Overall, the subgroups in respective variants i.e. age: 27 +/- 0.8yr, body mass: 73 +/- 0.4 kg, height: 177 +/- 0.5 cm, and walking speed: 1.42 +/- 0.01 m/s exhibited relatively higher stability. Further, the Pearson correlation illustrated a signification stability relationship between body mass and other variants. This study provides evidence that the diversity in the healthy subjects' composition can cause uncertainty in diagnostic and rehabilitation measurements, which is important to consider in gait evaluations.