Running is an essential mode of human locomotion, during which ballistic aerial phases alternate with phases when a single foot contacts the ground. The spring-loaded inverted pendulum (SLIP) provides a starting point for modelling running, and generates ground reaction forces that resemble those of the centre of mass (CoM) of a human runner. Here, we show that while SLIP reproduces within-step kinematics of the CoM in three dimensions, it fails to reproduce stability and predict future motions. We construct SLIP control models using data-driven Floquet analysis, and show how these models may be used to obtain predictive models of human running with six additional states comprising the position and velocity of the swing-leg ankle. Our methods are general, and may be applied to any rhythmic physical system. We provide an approach for identifying an event-driven linear controller that approximates an observed stabilization strategy, and for producing a reduced-state model which closely recovers the observed dynamics.
Positions of the markers (motion capture)
This document indicates the location of the markers on each subject, which were used to record the kinematics.
markerpos.pdf
Experimental data subject 1: 1/6
Force and kinematic recordings from subject 1, dataset 1 of 6 consecutive recording sequences.
subj1_r1.zip
Experimental data subject 2: 2/6
Force and kinematic recordings from subject 2, dataset 2 out of 6 consecutive recording sequences.
subj2_r2.zip
Experimental data subject 1: 2/6
Force and kinematic recordings from subject 1, dataset 2 out of 6 consecutive recording sequences.
subj1_r2.zip
Experimental data subject 1: 3/6
Force and kinematic recordings from subject 1, dataset 3 out of 6 consecutive recording sequences.
subj1_r3.zip
Experimental data subject 1: 4/6
Force and kinematic recordings from subject 1, dataset 4 out of 6 consecutive recording sequences.
subj1_r4.zip
Experimental data subject 1: 5/6
Force and kinematic recordings from subject 1, dataset 5 out of 6 consecutive recording sequences.
subj1_r5.zip
Experimental data subject 1: 6/6
Force and kinematic recordings from subject 1, dataset 6 out of 6 consecutive recording sequences.
subj1_r6.zip
Experimental data subject 2: 1/6
Force and kinematic recordings from subject 2, dataset 1 out of 6 consecutive recording sequences.
subj2_r1.zip
Experimental data subject 2: 3/6
Force and kinematic recordings from subject 2, dataset 3 out of 6 consecutive recording sequences.
subj2_r3.zip
Experimental data subject 2: 4/6
Force and kinematic recordings from subject 2, dataset 4 out of 6 consecutive recording sequences.
subj2_r4.zip
Experimental data subject 2: 5/6
Force and kinematic recordings from subject 2, dataset 5 out of 6 consecutive recording sequences.
subj2_r5.zip
Experimental data subject 2: 6/6
Force and kinematic recordings from subject 2, dataset 6 out of 6 consecutive recording sequences.
subj2_r6.zip
Experimental data subject 3: 1/6
Force and kinematic recordings from subject 3, dataset 1 out of 6 consecutive recording sequences.
Note: record #5 is missing (corrupted data). We did not relabel record #6, to indicate that there is a lack of data of about 4 minutes duration between #4 and #6.
subj3_r1.zip
Experimental data subject 3: 2/6
Force and kinematic recordings from subject 3, dataset 1 out of 5 recording sequences.
Note: record #5 is missing (corrupted data). We did not relabel record #6, to indicate that there is a lack of data of about 4 minutes duration between #4 and #6.
subj3_r2.zip
Experimental data subject 3: 3/6
Force and kinematic recordings from subject 3, dataset 3 out of 5 recording sequences.
Note: record #5 is missing (corrupted data). We did not relabel record #6, to indicate that there is a lack of data of about 4 minutes duration between #4 and #6.
subj3_r3.zip
Experimental data subject 3: 4/6
Force and kinematic recordings from subject 3, dataset 4 out of 5 recording sequences.
Note: record #5 is missing (corrupted data). We did not relabel record #6, to indicate that there is a lack of data of about 4 minutes duration between #4 and #6.
subj3_r4.zip
Experimental data subject 3: 6/6
Force and kinematic recordings from subject 3, dataset 5 out of 5 recording sequences.
Note: record #5 is missing (corrupted data). We did not relabel record #6, to indicate that there is a lack of data of about 4 minutes duration between #4 and #6.
subj3_r6.zip
Experimental data subject 7: 1/6
Force and kinematic recordings from subject 7, dataset 1 out of 6 consecutive recording sequences.
subj7_r1.zip
Experimental data subject 7: 2/6
Force and kinematic recordings from subject 7, dataset 2 out of 6 consecutive recording sequences.
subj7_r2.zip
Experimental data subject 7: 3/6
Force and kinematic recordings from subject 7, dataset 3 out of 6 consecutive recording sequences.
subj7_r3.zip
Experimental data subject 7: 4/6
Force and kinematic recordings from subject 7, dataset 4 out of 6 consecutive recording sequences.
subj7_r4.zip
Experimental data subject 7: 5/6
Force and kinematic recordings from subject 7, dataset 5 out of 6 consecutive recording sequences.
subj7_r5.zip
Experimental data subject 7: 6/6
Force and kinematic recordings from subject 7, dataset 6 out of 6 consecutive recording sequences.
subj7_r6.zip
info
A description of the individual files
SLIP parameter
This is a collection of SLIP parameter, which yield in a forward simulation the same sequence of apex states as observed in the experiment. For details see manuscript and references therein.
slip_parameter.zip