Table 2.

Kinematic data for different applied horizontal-force conditions

AHF, % body wt Stride Frequency, Hz Time of Contact per Step, s Duty Factor
−6 1.46 ± 0.030.268 ± 0.009 0.39 ± 0.01
−31.45 ± 0.03 0.269 ± 0.0070.39 ± 0.01
0 1.40 ± 0.020.263 ± 0.003 0.37 ± 0.01
+31.41 ± 0.03 0.258 ± 0.0060.37 ± 0.01
+6 1.41 ± 0.030.260 ± 0.005 0.37 ± 0.01
+91.39 ± 0.03 0.261 ± 0.0070.36 ± 0.01
+12 1.40 ± 0.030.253 ± 0.006 0.35 ± 0.01
+151.43 ± 0.02 0.253 ± 0.0060.36 ± 0.01
  • There were no substantial changes in kinematic variables measured at each horizontal loading condition. Average stride frequency did not change significantly (P = 0.15) across all conditions. Both average time of contact and average duty factor (fraction of stride period that 1 foot spends in contact with ground) showed slight but significant trends (P = 0.03). Values represent means for 8 subjects ± SE of the mean.