Table 1.

Obstacle running

kleg (kN m-1)α0 (degrees)αR (degrees)αshift (degrees)ωR (deg s-1)l0 (m)lR (m)lshift (m)
Undisturbed running25.2±6.868.8±2.164.3±2.04.5±0.9137±90.932±0.0200.942±0.018-0.010±0.005
Disturbed running22.9±3.670.4±2.761.3±1.59.1±3.6159±210.949±0.0180.959±0.017-0.010±0.011
Difference (disturbed - undisturbed)-2.3±4.41.7±2.1-3.0±2.54.7±3.0*22±13*0.017±0.0210.017±0.0230±0.010
  • Values are means ± S.D. (N=5 subjects)

    kleg, leg stiffness; α0, angle of attack; αR, onset angle of retraction;α shift0R, angle swept during retraction; ωR, retraction velocity (mean value of the last 20 ms before touch-down); l0, leg length at touch-down; lR, leg length at onset of retraction; lshift=l0-lR, the shift in leg length during retraction (see Fig. 7)

    In the undisturbed condition, at least 39 steps are evaluated for each subject

    Between 3 and 4 disturbed steps are used during obstacle avoidance

    The leg stiffness is measured in the stance phase immediately following the disturbance

    Differences between undisturbed and disturbed data are evaluated for significance using a paired t-test

  • * P<0.05