Dataset Information

Stance and swing phase detection during level and slope walking in the cat: effects of slope, injury, subject and kinematic detection method.

ABSTRACT: In quadrupeds, there have been limited comparisons of gait timing events detection (e.g., paw contact, PC and paw-off, PO) determined from kinematics and forceplates. The goal of this study was to investigate the effect of different slopes (0, -27, +27°), recovery times after ankle extensor nerve injury and repair (2, 6, 12 weeks), subjects and detection methods on accuracy of kinematically derived PC and PO timings during feline walking. Right hindlimb kinematics and ground reaction forces (GRF) of 4 cats walking along a sloped walkway with embedded forceplates were recorded. A total of 963 walking cycles were analyzed. Gait timings were determined from five kinematic methods based on displacements, velocities or accelerations of hindlimb markers. GRF based 'gold standard' timings for PC and PO were used to determine the systematic and random error of kinematic timing. Systematic errors between the kinematic methods differed significantly (p<0.05). Methods based on vertical paw peak acceleration and velocity gave the smallest systematic errors for PC and PO, respectively. The smallest random errors (standard deviations) for PC and PO were demonstrated by method based on paw horizontal displacement relative to greater trochanter: 13.4ms and 6.6ms, respectively. Effects of slope and subject on systematic errors of kinematic methods were significant, whereas effects of recovery time after nerve injury were not. It was concluded that timing of gait events can be determined consistently using kinematics, although adjustments must be made to account for the systematic error which varies according to subject and slope condition.

SUBMITTER: Pantall A

PROVIDER: S-EPMC3362317 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Stance and swing phase detection during level and slope walking in the cat: effects of slope, injury, subject and kinematic detection method.

Pantall Annette A Gregor Robert J RJ Prilutsky Boris I BI

Journal of biomechanics 20120406 8

In quadrupeds, there have been limited comparisons of gait timing events detection (e.g., paw contact, PC and paw-off, PO) determined from kinematics and forceplates. The goal of this study was to investigate the effect of different slopes (0, -27, +27°), recovery times after ankle extensor nerve injury and repair (2, 6, 12 weeks), subjects and detection methods on accuracy of kinematically derived PC and PO timings during feline walking. Right hindlimb kinematics and ground reaction forces (GRF ...[more]

PMID: 22483230

Similar Datasets

Project description:This study investigated electrocortical dynamics of human walking across different unconstrained walking conditions (i.e., level ground (LW), ramp ascent (RA), and stair ascent (SA)). Non-invasive active-electrode scalp electroencephalography (EEG) signals were recorded and a systematic EEG processing method was implemented to reduce artifacts. Source localization combined with independent component analysis and k-means clustering revealed the involvement of four clusters in the brain during the walking tasks: Left and Right Occipital Lobe (LOL, ROL), Posterior Parietal Cortex (PPC), and Central Sensorimotor Cortex (SMC). Results showed that the changes of spectral power in the PPC and SMC clusters were associated with the level of motor task demands. Specifically, we observed α and β suppression at the beginning of the gait cycle in both SA and RA walking (relative to LW) in the SMC. Additionally, we observed significant β rebound (synchronization) at the initial swing phase of the gait cycle, which may be indicative of active cortical signaling involved in maintaining the current locomotor state. An increase of low γ band power in this cluster was also found in SA walking. In the PPC, the low γ band power increased with the level of task demands (from LW to RA and SA). Additionally, our results provide evidence that electrocortical amplitude modulations (relative to average gait cycle) are correlated with the level of difficulty in locomotion tasks. Specifically, the modulations in the PPC shifted to higher frequency bands when the subjects walked in RA and SA conditions. Moreover, low γ modulations in the central sensorimotor area were observed in the LW walking and shifted to lower frequency bands in RA and SA walking. These findings extend our understanding of cortical dynamics of human walking at different level of locomotion task demands and reinforces the growing body of literature supporting a shared-control paradigm between spinal and cortical networks during locomotion.

Project description:BackgroundSuccessful walking requires the execution of the pre-swing biomechanical tasks of body propulsion and leg swing initiation, which are often impaired post-stroke. While excess rectus femoris activity during swing is often associated with low knee flexion, previous work has suggested that deficits in propulsion and leg swing initiation may also contribute. The purpose of this study was to determine underlying causes of propulsion, leg swing initiation and knee flexion deficits in pre-swing and their link to stiff knee gait in individuals post-stroke.MethodsMusculoskeletal models and forward dynamic simulations were developed for individuals post-stroke (n = 15) and healthy participants (n = 5). Linear regressions were used to evaluate the relationships between peak knee flexion, braking and propulsion symmetry, and individual muscle contributions to braking, propulsion, knee flexion in pre-swing, and leg swing initiation.ResultsFour out of fifteen of individuals post-stroke had higher plantarflexor contributions to propulsion and seven out of fifteen had higher vasti contributions to braking on their paretic leg relative to their nonparetic leg. Higher gastrocnemius contributions to propulsion predicted paretic propulsion symmetry (p = 0.005) while soleus contributions did not. Higher vasti contributions to braking in pre-swing predicted lower knee flexion (p = 0.022). The rectus femoris had minimal contributions to lower knee flexion acceleration in pre-swing compared to contributions from the vasti. However, for some individuals with low knee flexion, during pre-swing the rectus femoris absorbed more power and the iliopsoas contributed less power to the paretic leg. Total musculotendon work done on the paretic leg in pre-swing did not predict knee flexion during swing.ConclusionsThese results emphasize the multiple causes of propulsion asymmetry in individuals post-stroke, including low plantarflexor contributions to propulsion, increased vasti contributions to braking and reliance on compensatory mechanisms. The results also show that the rectus femoris is not a major contributor to knee flexion in pre-swing, but absorbs more power from the paretic leg in pre-swing in some individuals with stiff knee gait. These results highlight the need to identify individual causes of propulsion and knee flexion deficits to design more effective rehabilitation strategies.

Dataset Information

Stance and swing phase detection during level and slope walking in the cat: effects of slope, injury, subject and kinematic detection method.

Publications

Stance and swing phase detection during level and slope walking in the cat: effects of slope, injury, subject and kinematic detection method.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets