Table 1.

Mechanical energy exchange factors

α (deg.)ΔKE/ΔGPE+Wext (J kg−1 step−1)+tWext (J kg−1 step−1)
−9° Down−7.33 (6.94)1.41 (0.67)0.15 (0.05)0.34 (0.07)
−6° Down2.97 (5.53)1.27 (0.76)0.16 (0.05)0.36 (0.06)
−3° Down12.91 (5.77)1.07 (0.35)0.24 (0.05)0.43 (0.06)
Level26.30 (6.77)0.94 (0.15)0.48 (0.06)0.48 (0.06)
+3° Up37.08 (10.94)0.62 (0.07)0.93 (0.09)0.59 (0.07)
+6° Up44.95 (11.68)0.44 (0.05)1.41 (0.14)0.82 (0.08)
+9° Up50.90 (12.30)0.35 (0.03)1.77 (0.25)0.97 (0.09)
  • Work due to fluctuations in combined energy excluding the overall work necessary to lower or raise the center of mass tWext.

    Values represent means (s.d.) for all 10 subjects.

    All downhill and uphill running conditions differed from level walking, P<0.0001.