CoChat
Sign Up
Cited by 130Neuroscience and Neural EngineeringMuscle activation and electromyography studiesVagus Nerve Stimulation Research

Selective stimulation of the human femoral nerve with a flat interface nerve electrode

Open access
Schiefer, M A, Polasek, K H, Triolo, R J, Pinault, G C J, Tyler, D J·2010·Journal of Neural Engineering
DOI 10.1088/1741-2560/7/2/026006PMC PMC2915830
Open this paper in CoChat — free account

Abstract

In humans, we tested the hypothesis that a flat interface nerve electrode (FINE) placed around the femoral nerve trunk can selectively stimulate each muscle the nerve innervates. In a series of intraoperative trials during routine vascular surgeries, an eight-contact FINE was placed around the femoral nerve between the inguinal ligament and the first nerve branching point. The capability of the FINE to selectively recruit muscles innervated by the femoral nerve was assessed with electromyograms (EMGs) of the twitch responses to electrical stimulation. At least four of the six muscles innervated by the femoral nerve were independently and selectively recruited in all subjects. Of these, at least one muscle was a hip flexor and at least two were knee extensors. Results from the intraoperative experiments were used to estimate the potential for the electrode to restore knee extension and hip flexion through functional electrical stimulation. Normalized EMGs and biomechanical simulations were used to estimate joint moments and functional efficacy. Estimated knee extension moments exceed the threshold required for the sit-to-stand transition.

AI snapshot

Written from the paper’s full text.

TL;DR

An eight-contact flat interface nerve electrode (FINE) placed on the human femoral nerve trunk during intraoperative trials selectively recruited at least four of the six innervated muscles in all four subjects with valid data. Biomechanical estimates indicated that selective knee extensor recruitment could generate sufficient knee extension moment for sit-to-stand while limiting unwanted hip flexion.

Key findings

  • At least four of the six muscles innervated by the femoral nerve were independently and selectively recruited in all subjects; all six were selectively recruited in one subject. At least one hip flexor and at least two knee extensors were selectively recruited in each subject.
  • The average threshold to elicit muscle contraction was 21 ± 18 nC. This was significantly lower than the 311 ± 100 nC reported for intramuscular electrodes (p ≪ 0.01) and not significantly different from spiral nerve cuff thresholds.
  • Under the strictest selectivity criterion, 18 of 23 recorded muscles were selectively recruited, with average spillover costs of 0.02 ± 0.02. When costs were limited to non-agonist muscles, 19 of 23 muscles were selectively recruited, with average costs of 0.02 ± 0.01.
  • Estimated knee extension moment averaged 82 ± 48 N m when hip flexion moment was restricted to ≤5 N m; in all subjects this exceeded the 35 N m sit-to-stand transition threshold. Estimated hip flexion of about 5 N m was obtainable in all subjects at 10% cost, and maximum estimated hip flexion exceeded 30 N m in one subject but with excess knee extension.

Methods

  • Intraoperative trials during routine lower extremity vascular surgeries: seven subjects consented, but valid data were collected from the last four. An eight-contact FINE was placed around the femoral nerve between the inguinal ligament and the first branching point.
  • Needle EMG electrodes were placed in the six muscles innervated by the femoral nerve; twitch responses to monopolar, charge-balanced, biphasic, cathodic-first stimulation were recorded. Recruitment curves used pulse-width and/or pulse-amplitude modulation.
  • Selectivity was quantified with a recruitment benefit/cost formula using a 10% cost threshold. Joint moments were estimated by scaling a SIMM biomechanical model’s maximum static moments by normalized EMG activation levels.

Limitations

  • The paper states that results were obtained over a short intraoperative period during which only a small portion of the stimulus space was explored; longer-term experiments were not conducted.
  • Moment estimates were indirect and assumed that chronic selectivity would not be significantly less than acute selectivity, that normalized EMG reflects maximum isometric force, and that a single EMG pair represents whole-muscle activity. The SIMM model did not initially account for muscle atrophy, though a 50% strength reduction still left estimated knee extension above 35 N m.
  • The paper also notes that selectivity costs weighted all muscles equally and did not include sensory fiber activation; if sensation is present or functional output is the goal, costs should be weighted differently. Evident from the text: only four of seven subjects yielded valid data, and no direct joint moment measurements were possible.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1088/1741-2560/7/2/026006

Cites

Statistics

Nothing to recompute.

Claims the paper makes

0 of 31 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    The FINE threshold was not significantly different from the 23 ± 8 nC and 29 ± 17 nC obtained in chronic studies with a spiral nerve cuff implanted on the distal femoral nerve in humans.

    “or the 23 ± 8 nC and 29 ± 17 nC obtained in chronic studies with a spiral nerve cuff implanted on the distal femoral nerve in humans (p = 0.38, p = 0.14, respectively; one-sided t-test) (Fisher et al 2008)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Fisher et al 2008

      Not checked in the free run.

  • Findingown data

    The threshold to elicit muscle contraction with the FINE averaged 21 ± 18 nC.

    “On average, the threshold to elicit muscle contraction was 21 ± 18 nC.”
    • Also stated in: § 3.1. Participation, duration and thresholds · plain
      “The threshold to elicit muscle contraction was 21 ± 18 nC.”
    Quote in the paperSubstantial claim
  • Findingown data

    The FINE threshold was not significantly different from the 18 ± 12 nC obtained during intraoperative evaluation of the spiral nerve cuff on the human femoral nerve.

    “the 18 ± 12 nC obtained during intraoperative evaluation of the spiral nerve cuff on the human femoral nerve (p = 0.38, one-sided t-test) (Polasek et al 2009)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Polasek et al 2009 source

      Not checked in the free run.

  • Findingown data

    In three of four subjects, these muscles could be functionally selectively activated to at least 49%.

    “and in three of four subjects, these muscles could be functional selectively activated to at least 49%.”
    Quote in the paperSubstantial claim
  • Findingreasoning

    In three cases, contacts at the outer edges of the cuff did not recruit any muscle above threshold.

    “In three cases, contacts at the outer edges of the cuff did not recruit any muscle above threshold.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 21
  • Classified as probably not a substantial claim. 13
  • The quote only partly states this claim. 2

  • May combine two claims.

    Findingown data

    In all subjects, two to five contacts were selective for knee extensors and one to five contacts were selective for hip flexors.

    “In all subjects, two to five contacts were selective for knee extensors and one to five contacts were selective for hip flexors.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Of the selectively recruited muscles, at least one was a hip flexor and at least two were knee extensors in each subject.

    “Of these, at least one muscle was a hip flexor and at least two were knee extensors.”
    • Also stated in: § 4. Discussion · plain
      “At least one hip flexor and two knee extensors were selectively activated in each subject.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    In subjects 4 through 7, the width across the nerve was between 8.0 and 10.0 mm and the height of the nerve was between 1.0 and 1.5 mm.

    “In subjects 4 through 7, the width across the nerve was between 8.0 and 10.0 mm. The height of the nerve was between 1.0 and 1.5 mm.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The second subject had a high stimulus threshold prior to placing the FINE, confirmed with a hand-held stimulator.

    “The second subject had a high stimulus threshold prior to placing the FINE, confirmed with a hand-held stimulator.”
    Quote in the paperNot a substantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Nineteen of the twenty three recorded muscles and at least four muscles in each subject were selectively recruited above threshold when costs were computed as a function of only the non-agonist muscles.

    “Nineteen of the twenty three recorded muscles and at least four muscles in each subject were selectively recruited above threshold.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The maximum estimated hip flexion moment exceeded the estimated 30 N m required for gait in one subject but resulted in excess of 30 N m of estimated knee extension.

    “The maximum estimated hip flexion moment exceeded the estimated 30 N m required for gait (Winter 1991, Piazza and Delp 1996) in one subject but resulted in excess of 30 N m of estimated knee extension.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Winter 1991

      Not checked in the free run.

    • cites Piazza and Delp 1996

      Not checked in the free run.

    • The authors state this as an assumption: The selectivity obtained in a chronic trial will not be significantly less than that obtained in these acute experiments.
    • The authors state this as an assumption: EMG can be used to estimate moment.
    • Rests on an assumption: The maximum voluntary contraction for a muscle based on SIMM simulations without accounting for atrophy is adequate for estimating moment.

  • May combine two claims.

    Findingown data

    In subject 6, the vastus lateralis was not selectively stimulated under the stricter cost criterion, but the recruitment benefit associated with the maximized selectivity increased to 0.77 ± 0.06 when vastus intermedius and vastus medialis activation could exceed threshold, indicating that the knee extensors were recruited simultaneously.

    “Although in subject 6, the vastus lateralis was not selectively stimulated under the stricter cost criterion, the recruitment benefit associated with the maximized selectivity increased to 0.77 ± 0.06 when vastus intermedius and vastus medialis activation could exceed threshold, indicating that the knee extensors were recruited simultaneously.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Average costs associated with spillover to non-target muscles were 0.02 ± 0.01 when costs were computed as a function of only the non-agonist muscles.

    “Average costs associated with spillover to non-target muscles were 0.02 ± 0.01.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Post-operative MMT scores matched or exceeded pre-operative MMT scores for subjects 1 and 4 through 7, indicating that the FINE had no adverse effects on the nerve.

    “For subjects 1 and 4 through 7, post-operative MMT scores matched or exceeded pre-operative MMT scores, indicating that the FINE had no adverse effects on the nerve.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    Continuities of all leads were measured post-operatively and all were intact.

    “Continuities of all leads were measured post-operatively and all were intact.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Here, the maximum voluntary contraction for a muscle was based on SIMM simulations that did not account for muscle weakness due to atrophy.

    “Here, the maximum voluntary contraction for a muscle was based on SIMM simulations that did not account for muscle weakness due to atrophy.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In similar experiments with a spiral nerve cuff electrode placed around the femoral nerve trunk, stimulation resulted in selective recruitment of no more than three muscles and only the sartorius could be consistently recruited in all subjects.

    “In similar experiments conducted with a spiral nerve cuff electrode placed around the femoral nerve trunk, stimulation resulted in selective recruitment of no more than three muscles and only the sartorius could be consistently recruited in all subjects [24].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [24] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    In these cases, the nerve was smaller than the FINE and it was likely that the current shunted through extraneural fluid to the return electrode.

    “In these cases, the nerve was smaller than the FINE and it was likely that the current shunted through extraneural fluid to the return electrode.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The Institutional Review Board of the LSCDVAMC approved the study and the subjects provided consent prior to participation.

    “The Institutional Review Board of the LSCDVAMC approved the study and the subjects provided consent prior to participation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Software and hardware problems prevented collection of a full data set during the first experiment.

    “Software and hardware problems prevented collection of a full data set during the first experiment.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    While data do not exist to support this for muscles of the anterior thigh, inaccuracies due to this assumption will be small and not affect the results.

    “While data do not exist to support this for muscles of the anterior thigh, inaccuracies due to this assumption will be small and not affect the results.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: EMG from a single pair of recording electrodes in a muscle represents the electrical activity of the entire muscle.

  • Classified as probably not a substantial claim.

    Premisecitation

    Others have shown that normalized EMG obtained with microwires represents whole-muscle activity in the human soleus.

    “Others have shown that normalized EMG obtained with microwires represents whole-muscle activity in the human soleus (Bogey et al 2000).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Bogey et al 2000

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    In the third subject, the nerve was embedded in scar tissue from previous surgeries and had an abnormal branching pattern, and the surgeon removed the subject from the study because an adequate implant location could not be safely found.

    “In the third subject, the nerve was embedded in scar tissue from previous surgeries and had an abnormal branching pattern. The surgeon removed the subject from the study because an adequate implant location could not be safely found.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Models indicate that selective muscle recruitment from a FINE on the femoral nerve trunk generates sufficient knee extension moment without hip flexion for a sit-to-stand transition and for the knee extension phase of gait.

    “Models indicate that selective muscle recruitment from a FINE on the femoral nerve trunk generates sufficient knee extension moment without hip flexion for a sit-to-stand transition and for the knee extension phase of gait.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The selectivity obtained in a chronic trial will not be significantly less than that obtained in these acute experiments.
    • The authors state this as an assumption: EMG can be used to estimate moment.
    • The authors state this as an assumption: EMG from a single pair of recording electrodes in a muscle represents the electrical activity of the entire muscle.
    • Rests on an assumption: The maximum voluntary contraction for a muscle based on SIMM simulations without accounting for atrophy is adequate for estimating moment.
    • Rests on an assumption: Inaccuracies due to the single-pair EMG assumption will be small and not affect the results.

  • May combine two claims.

    Premisecitation

    In acute experiments, Polasek et al (2009) showed that stimulation with a four-contact spiral electrode placed around the femoral nerve selectively recruited hip flexors but did not reliably recruit knee extensors.

    “In acute experiments, Polasek et al (2009) showed that stimulation with a four-contact spiral electrode placed around the femoral nerve selectively recruited hip flexors but did not reliably recruit knee extensors.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Polasek et al 2009 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    Valid data were collected from the last four subjects.

    “Valid data were collected from the last four subjects.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The exposed nerve was verified to be the femoral nerve by its response to stimulation delivered with a hand-held probe.

    “The exposed nerve was verified to be the femoral nerve by its response to stimulation delivered with a hand-held probe.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Multiple contacts on a single FINE would achieve sufficient knee extension moment from different muscles, demonstrating functional redundancy.

    “Multiple contacts on a single FINE would achieve sufficient knee extension moment from different muscles, demonstrating functional redundancy.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The response to stimulation with a hand-held stimulator attached to each pair of electrodes verified electrode placement.

    “The response to stimulation with a hand-held stimulator attached to each pair of electrodes verified electrode placement.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductreasoning

    Measurement of muscle moment was not possible during intraoperative trials; therefore, moments and the resulting function were estimated using a SIMM biomechanical model.

    “Measurement of muscle moment was not possible during intraoperative trials. Therefore, moments and the resulting function were estimated using a SIMM (software for interactive musculoskeletal modeling, Musculographics Inc., SantaRosa, CA) biomechanical model (Wickiewicz et al 1983, Brand et al 1986, Delp 1990, Delp et al 1990, Friederich and Brand 1990, Schiefer et al 2008).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Wickiewicz et al 1983

      Not checked in the free run.

    • cites Brand et al 1986

      Not checked in the free run.

    • cites Delp 1990

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Fisher et al (2008) placed a multi-contact spiral nerve cuff electrode on the distal branch of the femoral nerve innervating the vasti in chronic human trials; compared to muscle-based electrodes, the legs supported 50% more body weight during standing and the maximal standing time increased fivefold using the nerve cuff.

    “Fisher et al (2008) placed a multi-contact spiral nerve cuff electrode on the distal branch of the femoral nerve innervating the vasti in chronic human trials. Compared to muscle-based electrodes, the legs supported 50% more body weight during standing and the maximal standing time increased fivefold using the nerve cuff.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Fisher et al 2008

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    The cost threshold was defined as 10% of the maximum activation observed for any non-target muscle, which has been shown to correspond to the first visible or palpable muscle twitch.

    “Based on prior work, the cost threshold was defined as 10% of the maximum activation observed for any non-target muscle (Tyler and Durand 2002, Tarler and Mortimer 2003, Polasek et al 2007), which has been shown to correspond to the first visible or palpable muscle twitch (Polasek et al 2007).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Tyler and Durand 2002

      Not checked in the free run.

    • cites Tarler and Mortimer 2003

      Not checked in the free run.

    • cites Polasek et al 2007

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisereasoning

    A single multi-contact nerve electrode can reduce surgery time because it requires only a single site for implantation.

    “Additionally, a single multi-contact nerve electrode can reduce surgery time because it requires only a single site for implantation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Premisereasoning

    An extraneural cuff electrode requires less current than muscle-based electrodes, reducing energy required for stimulation and potentially extending stimulator battery life.

    “It also requires less current than muscle-based electrodes. This reduces the energy required for stimulation and may extended stimulator battery life.”
    Quote in the paperNot a substantial claim
29 of 29

  • The authors state this as an assumption.

    The selectivity obtained in a chronic trial will not be significantly less than that obtained in these acute experiments.

    “Moment estimates were made under the assumption that the selectivity obtained in a chronic trial will not be significantly less than that obtained in these experiments.”

  • The authors state this as an assumption.

    EMG can be used to estimate moment.

    “It was assumed that EMG can be used to estimate moment.”

  • The authors state this as an assumption.

    EMG from a single pair of recording electrodes in a muscle represents the electrical activity of the entire muscle.

    “Another assumption was that EMG from a single pair of recording electrodes in a muscle represents the electrical activity of the entire muscle.”

  • The paper relies on this without support.

    A neuroprosthesis user with a complete SCI is unlikely to experience discomfort from activated sensory fibers.

    “A neuroprosthesis user with a complete SCI is unlikely to experience discomfort from activated sensory fibers.”

  • The paper relies on this without support.

    The maximum voluntary contraction for a muscle based on SIMM simulations without accounting for atrophy is adequate for estimating moment.

    “Here, the maximum voluntary contraction for a muscle was based on SIMM simulations that did not account for muscle weakness due to atrophy.”

  • The paper relies on this without support.

    Inaccuracies due to the single-pair EMG assumption will be small and not affect the results.

    “While data do not exist to support this for muscles of the anterior thigh, inaccuracies due to this assumption will be small and not affect the results.”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • EMG recordings are commonly used to infer selectivity, but their strong dependence on the spatial relationship between recording electrodes and activated motor units limits practical utility and can lead to over- or underestimation of selectivity.

    “Electromyogram recordings are commonly used to infer selectivity, but the strong dependence on the spatial relationship between the recording electrodes and the activated motor units limits the practical utility of this method and can lead to over- or underestimation of selectivity [4,10].”

    From Optimization of selective stimulation parameters for multi-contact electrodes (2013) · cites this paper as [4]

  • Control of multiple agonist motor unit populations with a single electrode could allow for better control of joint moment by varying the number of motor units recruited by the electrode.

    “Control of multiple agonist motor unit populations with a single electrode could allow for better control of joint moment by varying the number of motor units recruited by the electrode [4].”

    From Optimization of selective stimulation parameters for multi-contact electrodes (2013) · cites this paper as [4]

  • There is a linear relationship between the shape of isometric twitch and tetanic recruitment curves, characterized by a single scalar multiplier.

    “Studies in both animals and humans have demonstrated that there is a linear relationship between the shape of isometric twitch and tetanic recruitment curves, characterized by a single scalar multiplier [4,23].”

    From Optimization of selective stimulation parameters for multi-contact electrodes (2013) · cites this paper as [4]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Femoral-nerve comparison cites a cat sciatic-nerve study

    Minor

    The cited reference [24] is listed as a study of the cat sciatic nerve, not the spiral-cuff experiments on the human femoral nerve described in the sentence.

1 of 1

The citation lists haven’t been fetched yet

References 45 · Cited by 130

Research works printed but not linked: 6

  1. Daly J J, 2001, J. Rehabil. Res. Dev., 38, 513
  2. Gray H, 1918, Anatomy of the Human Body
  3. Grill W M, 1991, Proc. 13th Int. Conf. IEEE Eng. Med. Biol. Soc.
  4. Triolo R, 2001, J. Rehabil. Res. Dev., 38, 545
  5. Triolo R J, 1996, Human Motion Analysis, 318
  6. Winter D A, 1991, Biomechanics of Motor Control and Human Gait

Authors
Schiefer, M. A., Polasek, K. H., Triolo, R. J., Pinault, G. C. J., & Tyler, D. J.
Affiliations
  • Case Western Reserve University (US)
  • Louis Stokes Cleveland VA Medical Center (US)
Corresponding author
Pinault, G C J
ORCID
Venue
Journal of Neural Engineering
Publisher
IOP Publishing
Published
2010-03-08
Volume
7
Issue
2
Pages
026006
ISSN
  • 1741-2552 (ISSN-L)
  • 1741-2560
DOI
10.1088/1741-2560/7/2/026006
PMC
PMC2915830
OpenAlex
W1988806335
Semantic Scholar
39b814e51ffef9ddb02bb7f60977c86b6b2f34e9
Cited by
130
References
45
Citations by year
2026: 2 · 2025: 6 · 2024: 7 · 2023: 4 · 2022: 7 · 2021: 5 · 2020: 10 · 2019: 6 · 2018: 9 · 2017: 9 · 2016: 8 · 2015: 10 · 2014: 9 · 2013: 15 · 2012: 10
FWCI
4.92
Type
journal article
Language
en
Open access
Locations
  • Journal of Neural Engineering (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • National Institute of Biomedical Imaging and Bioengineering (R01EB001889)
  • Nuclear Physics
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neural Engineering
  • Physical Sciences › Engineering › Biomedical Engineering › Muscle activation and electromyography studies
  • Life Sciences › Neuroscience › Neurology › Vagus Nerve Stimulation Research
Keywords
femoral nerve, functional electrical stimulation, intraoperative nerve stimulation, knee extension, hip flexion, joint moments, biomechanical simulation, sit-to-stand
MeSH terms
Biomechanical Phenomena, Computer Simulation, Electric Stimulation, Electrodes, Implanted, Electromyography, Femoral Nerve, Follow-Up Studies, Hip, Humans, Knee, Models, Biological, Movement, Muscle, Skeletal

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review