Gait characterization via dynamic joint stiffness

Davis, Roy B.; DeLuca, Peter A.

doi:10.1016/0966-6362(95)01045-9

Cited by 165 publications

(119 citation statements)

References 13 publications

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“…Duration of second rocker was identified. Ankle stiffness during second rocker was defined using the method defined by Davis and DeLuca [31]. The magnitude of plantar loading was quantified as the peak pressure sustained under the metatarsal head region in the forefoot during stance.…”

Section: Gait Testingmentioning

confidence: 99%

Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy

2006

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Introduction-The purpose of our study was to examine the relationship between ankle dorsiflexion (DF) range of motion (ROM) and stiffness measured at rest (passively) and plantar loading during gait in individuals with and without diabetes mellitus (DM) and sensory neuropathy. Specifically, we sought to address three questions for this at-risk patient population: (1) Does peak passive DF ROM predict ankle DF ROM used during gait? (2) Does passive ankle stiffness predict ankle stiffness used during gait? (3) Are any of the passive or gait-related ankle measures associated with plantar loading?Methods-Ten subjects with DM and 10 age and gender matched non-diabetic control subjects participated in this study. Passive ankle DF ROM and stiffness were measured with the Iowa Ankle ROM device. Kinematic, kinetic and plantar pressure data were collected as subjects walked at 0.89 m/s.Results-We found that subjects with DM have reduced passive ankle DF ROM and increased stiffness compared to non-diabetic control subjects, however, subjects with DM demonstrated ankle motion, stiffness and plantar pressures, similar to control subjects, while walking at the identical speed, 0.89 m/s (2 mph). These data indicate that clinical measures of heel cord tightness and stiffness do not represent ankle motion or stiffness utilized during gait. Our findings suggest that subjects with DM utilize strategies such as shortening their stride length and reducing their push-off power to modulate plantar loading.

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Section: Gait Testingmentioning

confidence: 99%

Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy

2006

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“…In a different study, subjects stood on a swaying cradle that perturbed the ankle to quantify the stiffness in IE (Zinder et al 2007). Ankle stiffness has also been studied during walking at various speeds (Davis and DeLuca 1996;Hansen et al 2004;Palmer 2002).…”

Section: Introductionmentioning

confidence: 99%

Estimating the multivariable human ankle impedance in dorsi-plantarflexion and inversion-eversion directions using EMG signals and artificial neural networks

Dallali

Knop

Castelino

et al. 2017

Int J Intell Robot Appl

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The use of a suitably designed ankle-foot prosthesis is essential for transtibial amputees to regain lost mobility. A desired ankle-foot prosthesis must be able to replicate the function of a healthy human ankle by transferring the ground reaction forces to the body, absorbing shock during contact, and providing propulsion. During the swing phase of walking, the human ankle is soft and relaxed; however, it hardens as it bears the body weight and provides force for push-off. The stiffness is one of the components of the mechanical impedance, and it varies with muscle activation (Stochastic estimation of human ankle mechanical impedance in medial-lateral direction, 2014, Stochastic estimation of the multivariable mechanical impedance of the human ankle with active muscles, 2010). This study defines the relationship between ankle impedance and the lower extremity muscle activations using artificial neural networks (ANN). We used the Anklebot, a highly backdrivable, safe, and therapeutic robot to apply stochastic position perturbations to the human ankle in the sagittal and frontal planes. A previously proposed system identification method was used to estimate the target ankle impedance to train the ANN. The ankle impedance was estimated with relaxed muscles and with lower leg muscle activations at 10 and 20% of the maximum voluntary contraction (MVC) of each individual subject. Given the root mean squared (rms) of the electromyography (EMG) signals, the proposed ANN effectively predicted the ankle impedance with mean accuracy of 89.8 ± 6.1% in DP and mean accuracy of 88.3 ± 5.7% in IE, averaged across three muscle activation levels and all subjects.

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“…Analysis of the foot joints dynamics during gait can help understanding the development of these injuries [3]. Different works undertook this analysis by looking at the dynamic joint stiffness [4], [5], defined as the ratio between the external moment applied to the joint and the joint angle, at a specific time, assessed while performing activities that require muscle activation, such as walking. This stiffness combines the effect of muscle forces, inertia and deformation of soft tissue, and was already applied to the ankle in the sagittal plane with different purposes [4], [6], [7].…”

Section: Introductionmentioning

confidence: 99%

Effect of static foot posture on the dynamic stiffness of foot joints during walking

et al. 2018

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This study aimed to analyse the dynamic stiffness of foot joints during gait in the sagittal plane in feet with different static foot postures. Seventy healthy adult male subjects with different static postures, assessed by the Foot Posture Index (FPI) (30 normal, 20 highly pronated and 20 highly supinated), were recruited. Kinematic and kinetic data were recorded using an optical motion capture system and a pressure platform, and dynamic stiffness at the different stages of the stance was calculated from the slopes of the linear regression on the flexion moment-angle curves. The effect of foot type on dynamic stiffness and on ranges of motion and moments was analysed using ANOVAs and post-hoc tests, and linear correlation between dynamic stiffness and FPI was also tested. Highly pronated feet showed a significantly smaller range of motion at the ankle and metatarsophalangeal joints and also a larger range of moments at the metatarsophalangeal joint than highly supinated feet. Dynamic stiffness during propulsion was significantly greater at all foot joints for highly pronated feet, with positive significant correlations, although small, with the squared FPI. Highly supinated feet showed greater dynamic stiffness than normal feet, although to a lesser extent. Highly pronated feet during normal gait experienced greatest decrease in the dorsiflexor moments during propulsion. Normal feet were found to be the most balanced regarding work generated and absorbed.

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Gait characterization via dynamic joint stiffness

Cited by 165 publications

References 13 publications

Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy

Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy

Estimating the multivariable human ankle impedance in dorsi-plantarflexion and inversion-eversion directions using EMG signals and artificial neural networks

Effect of static foot posture on the dynamic stiffness of foot joints during walking

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