Table 1.

Metabolic and kinetic data for different applied horizontal-force conditions

AHF (%body wt)o2, ml ⋅ kg−1 ⋅ min−1Braking Impulse, N/s Propulsive Impulse, N/sPeak Braking Force, N Peak Propulsive Force, N Peak Vertical Force, N
−645.7 ± 1.1 6.8 ± 0.5 20.8 ± 1.3147.4 ± 6.0 238.0 ± 11.4 1,574 ± 91
−3 39.7 ± 0.9 10.1 ± 0.716.9 ± 1.1 189.3 ± 8.3 210.9 ± 10.91,583 ± 94
0 35.1 ± 1.013.9 ± 0.6 14.1 ± 0.6 227.2 ± 6.6193.3 ± 7.0 1,670 ± 72
+330.4 ± 1.2 18.3 ± 1.2 11.7 ± 0.9267.9 ± 15.7 172.3 ± 10.51,664 ± 126
+6 27.1 ± 1.222.9 ± 1.7 9.2 ± 0.7 293.8 ± 15.0141.0 ± 9.5 1,633 ± 128
+925.2 ± 1.3 27.9 ± 2.0 7.5 ± 0.7331.4 ± 15.5 123.1 ± 8.41,650 ± 137
+12 24.3 ± 1.433.2 ± 2.1 5.4 ± 0.6 387.5 ± 15.598.3 ± 8.5 1,699 ± 143
+1523.7 ± 1.6 37.9 ± 2.5 4.2 ± 0.6438.8 ± 20.5 83.3 ± 8.11,707 ± 114
  • Average active peak of vertical ground reaction force (GRF) did not change significantly across all horizontal loading conditions (P = 0.77). In contrast, at an impeding force of −6% body wt applied horizontal force (AHF), average peak braking GRF was 65% of zero AHF value and average peak propulsive GRF was 123% of control value. At an aiding force of +15% body wt AHF, average peak braking GRF was 193% of control value and average peak propulsive GRF was 43% of control value. Values represent means for 8 subjects ± SE of the mean. All variables showed significant trends (P < 0.01) except for mean active peak of vertical GRF.