Challenging gait leads to stronger lower-limb kinematic synergies: The effects of walking within a more narrow pathway

Rosenblatt, Noah J.; Latash, Mark L.; Hurt, Christopher P.; Grabiner, Mark D.

doi:10.1016/j.neulet.2015.05.039

Cited by 30 publications

(14 citation statements)

References 20 publications

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“…Changes in similar parameters have previously been shown to alter the joint dynamics during regular treadmill walking. Specifically, constraints introduced during treadmill walking in terms of a narrow and straight walking path and a constant speed has been observed to lead to lower joint movement variability compared with overground walking [34–36]. In contrast to these observations, the joint angle movements, in this study, were more variable during stairmill climbing suggesting that a higher number of different movement solutions were used to solve the task of stairmill climbing.…”

Section: Discussioncontrasting

confidence: 57%

Lower limb joint angle variability and dimensionality are different in stairmill climbing and treadmill walking

et al. 2018

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The present study tested if the quadratic relationship which exists between stepping frequency and gait dynamics in walking can be generalized to stairmill climbing. To accomplish this, we investigated the joint angle dynamics and variability during continuous stairmill climbing at stepping frequencies both above and below the preferred stepping frequency (PSF). Nine subjects performed stairmill climbing at 80, 90, 100, 110 and 120% PSF and treadmill walking at preferred walking speed during which sagittal hip, knee and ankle angles were extracted. Joint angle dynamics were quantified by the largest Lyapunov exponent (LyE) and correlation dimension (CoD). Joint angle variability was estimated by the mean ensemble standard deviation (meanSD). MeanSD and CoD for all joints were significantly higher during stairmill climbing but there were no task differences in LyE. Changes in stepping frequency had only limited effect on joint angle variability and did not affect joint angle dynamics. Thus, we concluded that the quadratic relationship between stepping frequency and gait dynamics observed in walking is not present in stairmill climbing based on the investigated parameters.

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Section: Discussioncontrasting

confidence: 57%

Lower limb joint angle variability and dimensionality are different in stairmill climbing and treadmill walking

et al. 2018

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“…The uncontrolled manifold hypothesis suggests that motor control stabilises the centre of mass though multijoint synergies that limit variation in the displacement trajectory and the limbs not interfering with each other. This leads to complex feedback and feed‐forward systems that stabilise the trajectory . The mediolateral excursion amplitude is low and the control mechanisms described above likely make the kinematic stride‐to‐stride variation during swing too large to be of diagnostic value.…”

Section: Discussionmentioning

confidence: 99%

Kinematic discrimination of ataxia in horses is facilitated by blindfolding

Olsen

Fouché

Jordan

et al. 2017

Equine Veterinary Journal

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Summary Background Agreement among experienced clinicians is poor when assessing the presence and severity of ataxia, especially when signs are mild. Consequently, objective gait measurements might be beneficial for assessment of horses with neurological diseases. Objectives To assess diagnostic criteria using motion capture to measure variability in spatial gait‐characteristics and swing duration derived from ataxic and non‐ataxic horses, and to assess if variability increases with blindfolding. Study design Cross‐sectional. Methods A total of 21 horses underwent measurements in a gait laboratory and live neurological grading by multiple raters. In the gait laboratory, the horses were made to walk across a runway surrounded by a 12‐camera motion capture system with a sample frequency of 240 Hz. They were made to walk normally and with a blindfold in at least three trials each. Displacements of reflective markers on head, fetlock, hoof, fourth lumbar vertebra, tuber coxae and sacrum derived from three to four consecutive strides were processed and descriptive statistics, receiver operator characteristics (ROC) to determine the diagnostic sensitivity, specificity and area under the curve (AUC), and correlation between median ataxia grade and gait parameters were determined. Results For horses with a median ataxia grade ≥2, coefficient of variation for the location of maximum vertical displacement of pelvic and thoracic distal limbs generated good diagnostic yield. The hoofs of the thoracic limbs yielded an AUC of 0.81 with 64% sensitivity and 90% specificity. Blindfolding exacerbated the variation for ataxic horses compared to non‐ataxic horses with the hoof marker having an AUC of 0.89 with 82% sensitivity and 90% specificity. Main limitations The low number of consecutive strides per horse obtained with motion capture could decrease diagnostic utility. Conclusions Motion capture can objectively aid the assessment of horses with ataxia. Furthermore, blindfolding increases variation in distal pelvic limb kinematics making it a useful clinical tool.

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“…The UCM approach has been described in detail elsewhere (Scholz and Schöner, 1999; Latash et al, 2007) as has its application to stabilizing the swing limb trajectory during gait (Rosenblatt et al, 2015; Eckardt and Rosenblatt, 2018). Briefly, motion capture data was normalized to 0–100% corresponding to left toe off to heel strike.…”

Section: Methodsmentioning

confidence: 99%

Instability Resistance Training Decreases Motor Noise During Challenging Walking Tasks in Older Adults: A 10-Week Double-Blinded RCT

Eckardt

Rosenblatt

2019

Front. Aging Neurosci.

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Locomotor stability is challenged by internal perturbations, e.g., motor noise, and external perturbations, e.g., changes in surface compliance. One means to compensate for such perturbations is to employ motor synergies, defined here as co-variation among a set of elements that acts to stabilize, or provide similar trial-to-trial (or step-to-step) output, even in the presence of small variations in initial conditions. Whereas evidence exists that synergies related to the upper extremities can be trained, the extent to which lower limb synergies, such as those which may be needed to successfully locomote in complex environments, remains unknown. The purpose of this study was to evaluate if resistance training (RT) in unstable environments could promote coordination patterns associated with stronger synergies during gait. Sixty-eight participants between the age of 65 and 80 were randomly assigned to one of three different RT modalities: stable whole-limb machine-based RT (S-MRT), instability free-weight RT (I-FRT), and stable machine-based adductor/abductor RT (S-MRT HIP ). Before and after RT, participants walked across an even lab floor and a more challenging uneven surface with and without holding a weighted bag. The uncontrolled manifold control analysis (UCM) was used to calculate the synergy index (i.e., strength of the kinematic synergy) related to stabilization of our performance variable, the mediolateral trajectory of the swing foot, under each condition. Regardless of RT group, there was no effect of RT on the synergy index when walking across the even lab floor. However, the synergy index during the two uneven surface conditions was stronger after I-FRT but was not affected by the other RT modalities. The stronger synergy index for the I-FRT group was due to improved coordination as quantified by an overall increase in variability in elemental variable space but a decrease in the variability that negatively affects performance. The unstable environment offered by I-FRT allows for exploration of motor solutions in a manner that appears to transfer to challenging locomotor tasks. Introducing tasks that promote, rather than limit, exploration of motor solutions seems to be a valuable exercise modality to strengthen kinematic synergies that cannot be achieved with traditional strengthening paradigms (e.g., S-MRT). Clinical Trial Registration: www.ClinicalTrials.gov , identifier NCT03017365.

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Challenging gait leads to stronger lower-limb kinematic synergies: The effects of walking within a more narrow pathway

Cited by 30 publications

References 20 publications

Lower limb joint angle variability and dimensionality are different in stairmill climbing and treadmill walking

Lower limb joint angle variability and dimensionality are different in stairmill climbing and treadmill walking

Kinematic discrimination of ataxia in horses is facilitated by blindfolding

Instability Resistance Training Decreases Motor Noise During Challenging Walking Tasks in Older Adults: A 10-Week Double-Blinded RCT

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