The frequency content of gait

Antonsson, Erik K.; Mann, Robert W.

doi:10.1016/0021-9290(85)90043-0

Cited by 499 publications

(187 citation statements)

References 15 publications

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“…Load cell data were decimated to 120 Hz to match the sampling rate of the marker data. Force and moment signals were then low-pass filtered using a fourth-order, low-pass, bidirectional Butterworth filter with an effective cut-off frequency of 50 Hz [37,38]. Using a custom MATLAB® program, forces and moments measured by the load cell were transformed into the global coordinate system :…”

Section: Discussionmentioning

confidence: 99%

The biomechanical response of persons with transfemoral amputation to variations in prosthetic knee alignment during level walking

2016

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Prosthetic alignment is an important factor in the overall fit and performance of a lower-limb prosthesis. However, the association between prosthetic alignment and control strategies used by persons with transfemoral amputation to coordinate the movement of a passive prosthetic knee is poorly understood. This study investigated the biomechanical response of persons with transfemoral amputation to systematic perturbations in knee joint alignment during a level walking task. Quantitative gait data were collected for three alignment conditions: bench alignment, 2 cm anterior knee translation (ANT), and 2 cm posterior knee translation (POST). In response to a Participation Follow-Up: The authors do not plan to inform participants of the publication of this study. However, participants have been encouraged to check the Northwestern University Prosthetics-Orthotics Center Web site for updated publications related to the program's activities, which include the present study. Disclaimer:The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the VA or the U.S. Government. U.S. Department of Veterans AffairsPublic Access Author manuscript J Rehabil Res Dev. Author manuscript; available in PMC 2017 August 17. VA Author ManuscriptVA Author Manuscript VA Author Manuscript destabilizing alignment perturbation (ANT), subjects significantly increased their early-stance hip extension moment, confirming that persons with transfemoral amputation rely on a hip extensor strategy to maintain knee joint stability. However, subjects also decreased the rate at which they loaded their prosthesis, decreased their step length, increased their trunk flexion, and maintained their limb in a more vertical posture at the time of opposite toe off. Collectively, these results suggest that persons with transfemoral amputation rely on a combination of strategies to coordinate stance-phase knee flexion. Further, no significant changes were observed in response to the POST condition, suggesting that a bias toward posterior alignment may have fewer implications in terms of stance-phase, knee-joint control.

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Section: Discussionmentioning

confidence: 99%

The biomechanical response of persons with transfemoral amputation to variations in prosthetic knee alignment during level walking

2016

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“…Marker trajectories from the motion analysis collection were low pass filtered at 6 Hz and force plate data was low passed filtered at 40 Hz [2] with a recursive fourth order Butterworth digital filter. Sagittal plane hip, knee and ankle joint angles were calculated using rigid body analysis (Visual3D, Version 2.84, C-Motion, Inc., Rockville, MD).…”

Section: Data Management and Analysismentioning

confidence: 99%

Altered loading during walking and sit‐to‐stand is affected by quadriceps weakness after total knee arthroplasty

Mizner

Snyder‐Mackler

2005

Journal Orthopaedic Research

312

247

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Purpose: Total knee arthroplasty (TKA) successfully reduces pain, but has not achieved comparable improvements in function. We hypothesized that quadriceps strength affects performance by altering loading and movement patterns during functional tasks.Methods: Fourteen subjects with isolated, unilateral TKA were tested three months after surgery. Quadriceps strength was assessed isometrically and kinematics, kinetics, and EMG were collected during level walking and sit-to-stand (STS). Function was assessed using the timed up and go test (TUG), stair climbing test (SCT), and the 6 min walk test (6MW).Results: Functional performance was significantly related to the quadriceps strength of both legs, but was more strongly related to the uninvolved strength (involved rho = -0.43 with TUG; -0.65 with SCT; 0.64 with 6MW) (uninvolved rho = -0.63 with TUG; -0.68 with SCT; 0.77 with 6MW). During STS, subjects shifted weight away from the operated limb (p < 0.01). Quadriceps muscle activity and the extension moments at the knee and hip were smaller in the involved compared to the uninvolved (p < 0.05). The amount of asymmetry in knee excursion during weight acceptance in gait, the asymmetry in weight bearing from sit-to-stand, and the uninvolved hip extension moment during STS were related to the amount of asymmetry in quadriceps strength (rho > 0.56, p < 0.05).Conclusions: Quadriceps weakness in patients with TKA has a substantial impact on the movement patterns and performance of the knee during functionally important tasks.

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“…One should keep in mind that many rhythms are present in the nervous system, in the musculoskeletal system and within all connective tissue. Frequencies from 5 to 30Hz were found during postural muscle activity (quiet standing) and of 10Hz during walking [39]. So everything in living systems is in motion and changing magnetic fields are associated with changing EF.…”

Section: Equivalent Counterpart In the Organism?mentioning

confidence: 99%

Does electromagnetic therapy meet an equivalent counterpart within the organism?

Funk¹

2017

J Transl Sci

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This review bundles all available new information about intrinsic electrical phenomena in many types of cells (also non-neural) and tissues and shows that exogenously applied electric fields (as DC -EF, EMF or pulsed electromagnetic fields PEMF) can couple to the endogenous electrical phenomena of the body. These endogenous fields are generated ubiquitously in all tissues via cellular ion pumps and transporters and these ion gradients can be transferred by gap junctions. Such electric phenomena can now be monitored in living cells and tissues by electro-sensitive markers. Observations are now available from early embryonic development on to wound healing and regeneration within the adult organism. Based on these grounds we demonstrate that endogenous electric fields act directly on classical pathways of molecular and cell biology. Adequately applied frequencies and pulsing from outside can couple to these endogenous fields or to the receptors of classical biochemical pathways and manifest in positive "reprogramming" of tissue functions. In sum, this new analytical approach to the bodies´ own electrical information processes opens up new avenues for adequate EMF and PEMF therapy.

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The frequency content of gait

Cited by 499 publications

References 15 publications

The biomechanical response of persons with transfemoral amputation to variations in prosthetic knee alignment during level walking

The biomechanical response of persons with transfemoral amputation to variations in prosthetic knee alignment during level walking

Altered loading during walking and sit‐to‐stand is affected by quadriceps weakness after total knee arthroplasty

Does electromagnetic therapy meet an equivalent counterpart within the organism?

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