Skip to main content

Table 1 Biomechanical and metabolic data for subjects

From: Using a simple rope-pulley system that mechanically couples the arms, legs, and treadmill reduces the metabolic cost of walking

Variable Normal
mean ± SD
Assisted
mean ± SD
% change n p
Net metabolic power (W/kg) 3.04 ± 0.58 2.53 ± 0.38 − 16.78* n = 8 0.001
Gross metabolic power (W/kg) 4.38 ± 0.59 3.87 ± 0.36 − 11.64 n = 8 n/a
Gross O2 (L/min) 0.921 ± 0.133 0.832 ± 0.156 − 9.67 n = 8 n/a
Normalized (L/min/kg) 0.013 ± 0.002 0.012 ± 0.001 − 7.69 n = 8 n/a
Respiratory exchange ratio 0.85 ± 0.04 0.80 ± 0.06 − 5.88 n = 8 0.077
Stride frequency (Hz) 0.91 ± 0.08 0.90 ± 0.08 − 1.10 n = 8 0.121
Vertical impulse (N·s) 404.47 ± 120.17 404.80 ± 116.13 0.08 n = 8 0.962
Normalized (N·s/BW) 0.5523 ± 0.016 0.5538 ± 0.017 0.27 n = 8 0.842
Braking impulse (N·s) − 24.55 ± 7.09 − 36.28 ± 12.14 47.78* n = 8 0.001
Normalized (N·s/BW) − 0.0337 ± 0.001 -0.0492 ± 0.002 45.99* n = 8 0.000
Propulsive impulse (N·s) 24.63 ± 7.36 13.53 ± 4.33 − 45.06* n = 8 0.003
Normalized (N·s/BW) 0.0337 ± 0.001 0.0192 ± 0.002 − 43.03* n = 8 0.000
Assistive impulse (N·s) n/a 16.39 ± 10.21 n/a n = 7 n/a
Normalized (N·s/BW) n/a 0.0208 ± 0.001 n/a n = 7 n/a
Peak assistive force (N) n/a 52.05 ± 21.99 n/a n = 7 n/a
Normalized (% BW) n/a 6.93 ± 1.81 n/a n = 7 n/a
  1. All comparisons were made between normal and assisted walking conditions with significance at P < 0.05. *Signifies significant differences between walking conditions. All comparisons were tested at an alpha level of 0.05 using a two-sided, paired samples t-test. n/a = not applicable