Swing-leg retraction, the backward rotation of the swing leg just prior to ground contact, is observed in human locomotion. While several advantages of swingleg retraction, like gait stability and perturbation rejection, are shown by conceptual models, there is currently very little experimental data on swing-leg retraction in human motion. In this paper, kinematic data for twenty-eight subject...

To achieve robust and stable legged locomotion in uneven terrain, animals must effectively coordinate limb swing and stance phases, which involve distinct yet coupled dynamics. Recent theoretical studies have highlighted the critical influence of swing-leg trajectory on stability, disturbance rejection, leg loading and economy of walking and running. Yet, simulations suggest that not all these ...

When walking (at moderate or fast speeds) or running, humans apply a burst hip torque to start leg swing and then again, at the end of the swing phase, to brake and reverse motion of their swing leg prior to heel-strike. The resulting rearward rotation of the swing leg, so called swingleg retraction, is also observed in animal gaits. Why is this retraction a common feature of many walking and r...

background: despite some successful dynamic simulation of self-impact double pendulum (sidp)-as humanoid robots legs or arms- studies, there is limited information available about the control of one leg locomotion. objective   : the main goal of this research is to improve the reliability of the mammalians leg locomotion and building more elaborated models close to the natural movements, by mod...

Using simple running models, researchers have argued that swing-leg retraction can improve running robot performance. In this paper, we investigate whether this holds for a more realistic simulation model validated against a physical running robot. We find that swing-leg retraction can improve stability and disturbance rejection. Alternatively, swing-leg retraction can simultaneously reduce tou...

Locomotion can be described as a subsequent series of stance and flight phases. In both phases the leg properties can be adapted. Here we consider spring-mass running with a linear adaptation of two leg parameters, leg angle and leg stiffness, during swing phase. The region of stability is characterized by the basin of attraction with sufficient reduction of a given perturbation within one step...

Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state o...

To investigate the metabolic cost and muscular actions required for the initiation and propagation of leg swing, we applied a novel combination of external forces to subjects walking on a treadmill. We applied a forward pulling force at each foot to assist leg swing, a constant forward pulling force at the waist to provide center of mass propulsion, and a combination of these foot and waist for...

Stick insect (Carausius morosus) leg muscles contract and relax slowly. Control of stick insect leg posture and movement could therefore differ from that in animals with faster muscles. Consistent with this possibility, stick insect legs maintained constant posture without leg motor nerve activity when the animals were rotated in air. That unloaded leg posture was an intrinsic property of the l...

PURPOSE The metabolic cost of walking increases when mass is added to the legs, but the effects of load magnitude and location on the energetics and biomechanics of walking are unclear. We hypothesized that with leg loading 1) net metabolic rate would be related to the moment of inertia of the leg (I(leg)), 2) kinematics would be conserved, except for heavy foot loads, and 3) swing-phase sagitt...