And Frequency of Arm and Leg Swing During Walking (original) (raw)
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Biomechanical mechanism for transitions in phase and frequency of arm and leg swing during walking
Biological Cybernetics, 2004
As humans increase walking speed, there are concurrent transitions in the frequency ratio between arm and leg movements from 2:1 to 1:1 and in the phase relationship between the movements of the two arms from in-phase to out-of-phase. Superharmonic resonance of a pendulum with monofrequency excitation had been proposed as a potential model for this phenomenon. In this study, an alternative model of paired pendulums with multiple-frequency excitations is explored. It was predicted that the occurrence of the concurrent transitions was a function of (1) changes in the magnitude ratio of shoulder accelerations at step and stride frequencies that accompany changes in walking speed and (2) proximity of these frequencies to the natural resonance frequencies of the arms modeled as a pair of passive pendulums. Model predictions were compared with data collected from 14 healthy young subjects who were instructed to walk on a treadmill. Walking speeds were manipulated between 0.18 and 1.52 m/s in steps of 0.22 m/s. Kinematic data for the arms and shoulders were collected using a 3D motion analysis system, and simulations were conducted in which the movements of a double-pendulum system excited by the accelerations at the suspension point were analyzed to determine the extent to which the arms acted as passive pendulums. It was confirmed that the acceleration waveforms at the shoulder are composed primarily of stride and step frequency components. Between the shoulders, the stride frequency components were out-of-phase, while the step frequency components were in-phase. The amplitude ratio of the acceleration waveform components at the step and stride frequencies changed as a function of walking speed and were associated with the occurrence of the transitions. Simulation results using these summed components as excitatory inputs to the double-pendulum system were in agreement with actual transitions in 80% of the cases. The potential role of state-dependent active muscle contraction at shoulder joints on the occurrence of the transitions was discussed. Due to the tendency of arm movements to stay in the vicinity of their primary resonance frequency, these active muscle forces were hypothesized to function as escapements that created limit cycle oscillations at the shoulder’s resonant frequency.
Human Movement Science, 2007
The present work investigated the eVects of spatial and neuromuscular constraints on the mean states and variability of interlimb coordination patterns performed in the para-sagittal plane of motion in a hand-held pendulum oscillation task. Nine right-handed students had to oscillate two pendulums through wrist adduction-abduction movements. Relative movement direction was manipulated by asking participants to perform both isodirectional and non-isodirectional movements. Participants were required to grab the pendulums either with both forearms in the same neutral or supine posture or with one forearm in neutral while the other one was in prone-inversed position. When both forearms were in a similar posture, isodirectional movements were generated predominantly by simultaneous activation of homologous muscle groups whereas non-isodirectional movements mainly resulted from simultaneous activation of non-homologous muscle groups. When forearms were in dissimilar posture, isodirectional movements were generated predominantly by the simultaneous activation of non-homologous muscle groups whereas non-isodirectional movements mainly resulted from simultaneous activation of homologous muscle groups. Standard deviation of relative phase and absolute error of relative phase were analyzed for each forearm posture condition. We hypothesized that neuromuscular and spatial constraints would aVect two diVerent aspects of coordination performance, i.e., pattern stability and accuracy, respectively. Comparison of the results obtained for similar and dissimilar postures suggested that changes of pattern stability were mediated by changes in the nature of the muscle activation patterns that gave rise to wrist movement in each condition. On the other hand, the results also showed that movement direction exclusively (J.J. Temprado). aVected phase shift. The Wndings are consistent with the conclusion of Park et al. . Dissociation of muscular and spatial constraints on patterns of interlimb coordination. Journal of Experimental Psychology: Human Perception and Performance, 27,[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] that neuromuscular constraints aVect variability of relative phase (attractor strength) and spatial constraints aVect the shift of relative phase (attractor location).
The Kapitza’s Pendulum as a Concurrent Strategy for Maintaining Upright Posture
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC)
A Kapitza's pendulum shows that it is possible to stabilize an inverted pendulum by making its base oscillate vertically. This action seems to introduce an inertial effect which will produce an attractor about the upright vertical position. This work shows that the upright posture of the trunk achieved while walking can be explained using a combination of a vertical oscillation and an angular stiffness regulation at the pelvis. This is shown with an estimated oscillation and stiffness obtained from video recordings of an unimpaired and a Parkinsoninan gaits. By simulating the dynamic model of the pendulum for a range of parameters, a series of stability conditions are found. They show that the introduction of the vertical oscillation results in a fast stabilization of the trunk and point to control strategies which rely on the system's dynamics.
IOP Conference Series: Materials Science and Engineering, 2018
This study attempts to model the human arm as a dynamical triple pendulum system. The equation of motion of te human arm was obtained using Euler-Lagrange equation. The resulted second order differential equation was solved analytically. Simulated results were presented with the aid of a computer software-Maple. It was observed that the angular displacement values of the three segments are directly proportional to their respective angular acceleration, which is in the modelling and analysis of human arm motion as a multiple pendulum system. Generally, the longer the segments of the human arm the longer it takes to swing back and forth, and the fewer back-and-forth swings there are in a second.
Vibration-Induced Changes in EMG During Human Locomotion
Journal of Neurophysiology, 2002
Verschueren, Sabine M. P., Stephan P. Swinnen, Kaat Desloovere, and Jacques Duysens. Vibration induced changes in EMG during human locomotion. . The present study was set up to examine the contribution of Ia afferent input in the generation of electromyographic (EMG) activity. Subjects walked blindfolded along a walkway while tendon vibration was applied continuously to a leg muscle. The effects of vibration were measured on mean EMG activity in stance and swing phase. The results show that vibration of the quadriceps femoris (Q) at the knee and of biceps femoris (BF) at the knee enhanced the EMG activity of these muscles and this occurred mainly in the stance phase of walking. These results suggest involvement of Ia afferent input of Q and BF in EMG activation during stance. In contrast, vibration of muscles at the ankle and hip had no significant effect on burst amplitude. Additionally, the onset time of tibialis anterior was measured to look at timing of phase transitions. Only vibration of quadriceps femoris resulted in an earlier onset of tibialis anterior within the gait cycle, suggesting involvement of these Ia afferents in the triggering of phase transitions. In conclusion, the results of the present study suggest involvement of Ia afferent input in the control of muscle activity during locomotion in humans. A limited role in timing of phase transitions is proposed as well.
Posturally induced transitions in rhythmic multijoint limb movements
Experimental Brain Research, 1993
The coordination dynamics (e.g., stability, loss of stability, switching) of multijoint arm movements are studied as a function of forearm rotation. Rhythmical coordination of flexion and extension of the right elbow and wrist was examined under the following conditions:
Kinematic and kinetic validity of the inverted pendulum model in quiet standing
Gait & Posture, 2004
Movements of the whole-body center of mass during quiet standing have been estimated from measurements of body segment movements. These whole-body center of mass movements have been compared with movements of the center of mass as predicted from a simple inverted-pendulum model of standing. However, the total body center of mass is a weighted average of the center of mass of all individual body segments. The question arises as to how well the total body center of mass represents the individual segments and lower limb joint angles. This study focuses on the validity of how well the individual segments and lower limb angles temporally and spatially synchronize with the total body center of mass. Eleven healthy university students volunteered to participate. Kinematic data were collected using a 3D optoelectronic camera system; kinetic data were collected using a 3D force plate. Participants stood quietly, with eyes open, for 120 s. Segment and whole body centers of mass were calculated from a 14 segment, 3D bilateral model. Segment and joint angles were calculated for the lower limbs, bilaterally, and the trunk. Segment center of mass root-mean-square displacements were strongly correlated with center of mass height relative to the ankle joint and were synchronized, or temporally locked, to the movement of the whole body center of mass. Sagittal plane ankle angular displacements were highly correlated to sagittal plane center of mass movement; stronger correlations between body center of mass and lower limb angular displacement were observed, the result of compensatory knee joint angular displacements. These data support and extend the use of an inverted pendulum model to represent quiet standing postural control.
Study of Gait Cycle Using a Five-Link Inverted Pendulum Model: First Developments
2019 IEEE 6th Portuguese Meeting on Bioengineering (ENBENG), 2019
Gait cycle has been the target of many studies in the last decades in order to identify the normal walking patterns of humans. The usefulness of these studies is of utmost importance to construct mathematical models that are capable to achieve stability during walking. Based on this fact, it seems justified the present effort to construct a model to simulate a complete stride in healthy humans. Thus, in this work, a five-link inverted pendulum model in the sagittal plane with 5 degrees of freedom (DOFs) based on Euler-Lagrange equations is being constructed with the main objective to concern stability during gait cycle. To do that, this study was divided into two parts: the first one is represented by this article and it is regarding to the model construction and data collection; the second part is relative to a future work and it concerns to the model validation and an analysis of the stiffness variation with the power and speed during gait cycle. Regarding to the results of the present study, good correlations were obtained between the data collected and the data presented in literature, which demonstrates a good data acquisition.
Alpha and beta oscillatory activity during a sequence of two movements
Clinical Neurophysiology, 2004
Objective: We studied movement-related electroencephalographic oscillatory changes in the alpha and beta range during a sequence of two movements in 7 healthy volunteers, in order to investigate the relationship between these changes and each component in the sequence.