Evaluation of tSCS treatment for the alleviation of lower limb spasticity

77 Pages·2016·19.51 MB·English

Evaluation of tSCS treatment
for the alleviation of lower limb spasticity
Halla Kristín Guðfinnsdóttir
Thesis of 60 ECTS credits
Master of Science in Biomedical Engineering

January 2016
Evaluation of tSCS treatment
for the alleviation of lower limb spasticity
Halla Kristín Guðfinnsdóttir
Thesis of 60 ECTS credits submitted to the School of Science and
Engineering
at Reykjavík University in partial fulfillment
of the requirements for the degree of
Master of Science in Biomedical Engineering

January 2016
Supervisor(s):
Þórður Helgason. Supervisor.
Associate Professor, Reykjavík University, Iceland
Guðbjörg Kristín Ludvigsdottir. Supervisor.
Rehabilitation specialist, Landspitali University Hospital, Iceland.
Examiner(s):
Stefán B. Sigurðsson, Examiner
Professor, University of Akureyri, Iceland.
Abstract:

  Introduction:
 Spinal
 cord
 injury
 is
 a
 traumatic
 injury
 of
 descending
 spinal

cord
 tracts
 that
 alters
 the
 supraspinal
 neural
 circuitry.
 Spasticity
 is
 a
 common

result
 of
 spinal
 cord
 injury
 (SCI)
 and
 can
 restrict
 daily
 living
 activities,
 cause
 pain

and
 fatigue
 and
 therefore
 decrease
 the
 quality
 of
 life
 for
 SCI
 individuals.
 The
 aim

of
  this
  study
  was
  to
  evaluate
  the
  effects
  of
  transcutaneous
  spinal
  cord

stimulation
 (tSCS)
 on
 individuals
 with
 post-­‐traumatic
 SCI
 for
 the
 alleviation
 of

lower
 limb
 spasticity.

  Methods:
  The
  evaluation
  of
  the
  effects
  of
  tSCS
  was
  done
  by
  means
  of

electrophysiological
  evaluation
  and
  evaluation
  of
  residual
  motor
  control

functions.
 The
 study
 protocol
 was
 divided
 into
 four
 stages,
 one
 treatment
 stage

and
 three
 assessments.
 The
 protocol
 starts
 with
 the
 first
 assessment
 for
 control

data,
 and
 then
 treatment
 was
 applied
 for
 30
 minuets,
 second
 assessment
 was

done
 immediately
 after
 stimulation
 and
 the
 last
 assessment
 two
 hours
 after

stimulation.
 The
 assessments
 consist
 of
 estimation
 of
 the
 Ashworth
 scale,
 clonus

beet
  quantification,
  10-­‐m
  walking
  test
  (if
  possible)
  and
  electrophysiological

evaluation
  (Brain
  Motor
  Control
  Assessment,
  BMCA)
  supplemented
  by
  the

Wartenberg
 pendulum
 test.

  Results:
 The
 results
 of
 the
 pendulum
 test
 show
 increase
 in
 muscle
 tone
 in

four
 subjects
 while
 the
 others
 presented
 average
 values
 ≥
 1,
 indicating
 non-­‐
spastic
  conditions.
  Nonetheless
  there
  was
  a
  significant
  difference
  of
  the

normalized
 EMG
 activity
 of
 all
 muscles
 before
 the
 stimulation
 and
 immediately

after
 stimulation
 for
 all
 participants,
 indication
 reduction
 in
 intrinsic
 phasic
 and

extrinsic
 spasticity.
 Enhancement
 of
 motor
 control
 was
 also
 observed.

  Conclusion:
  The
  similarity
  of
  the
  effects
  of
  tSCS
  with
  those
  induced
  by

epidural
 SCS,
 strongly
 suggests
 that
 both
 techniques
 are
 able
 to
 activate
 similar

neural
  structures.
  From
  our
  results
  we
  can
  see
  that
  the
  application
  of
  low-­‐
intensity
 tSCS
 for
 30
 minuets
 lead
 to
 the
 alleviation
 of
 lower
 limb
 spasticity

regardless
 of
 the
 clinical
 profile
 of
 the
 subjects
 and
 enhancement
 of
 voluntary

motor
 control
 in
 the
 motor
 incomplete
 SCI
 subjects.

Keywords:
  transcutaneous
  spinal
  cord
  stimulation
  (tSCS);
  spinal
  cord
  injury

(SCI);
 spasticity;
 Wartenberg
 pendulum
 test
 (WPT);
 Ashworth
 scale
 (AS).

  i
Útdráttur
 –
 Mat
 á
 áhrifum
 mænuraförvunar
 á
 síspennu

Inngangur:
  Áverki
  á
  mænu
  hefur
  áhrif
  á
  og
  getur
  breytt
  taugarásum
  og

tauganetum
 í
 mænunni.
 Síspenna
 eða
 ósjálfráður
 vöðvasamdráttur
 (spasmi),
 er

algengur
 fylgikvilli
 mænuskaða
 sem
 getur
 dregið
 verulega
 úr
 lífsgæðum
 vegna

hamlandi
  áhrifa
  á
  daglegar
  athafnir,
  sársauka
  og
  þreytu.
  Markmið

rannsóknarinnar
  er
  að
  meta
  áhrif
  raförvunar
  með
  yfirborðs-­‐rafskautum
  á

taugarætur
 í
 neðsta
 hluta
 mænunnar
 og
 meta
 hvort
 það
 geti
 dregið
 úr
 síspennu
 í

fótleggjum
  eftir
  mænuskaða.
  Til
  að
  meta
  áhrifin
  voru
  mismunandi
  matstæki

notuð
 sem
 meta
 ólík
 form
 síspennu,
 þ.e.
 taktbundin
 síspenna
 (intrinsic
 phasic)

og
 stífleika
 (intrinsic
 tonic)
 og
 síspenna
 vegna
 ytri
 áreitis
 (extrinsic
 spasticity).

  Aðferðir:
  Mat
  á
  áhrifum
  mænuraförvunarinnar
  var
  gerð
  með

raflífeðlisfræðilegum
  og
  klínískum
  athugunum
  sem
  og
  athugun
  á
  hreyfigetu.

Rannsókninni
 var
 skipt
 upp
 í
 fjóra
 áfanga,
 einn
 meðferðar-­‐
 og
 þrjá
 prófunar

áfanga.
  Fyrst
  var
  prófun,
  áfangi
  1,
  til
  að
  fá
  viðmiðunar
  gögn,
  síðan
  var

raförvunarmeðferð
 í
 30
 mínútur,
 þá
 prófunar
 áfangi
 2
 strax
 að
 lokinni
 meðferð

og
  loks
  þriðji
  prófunar
  áfanginn
  tveimur
  tímum
  eftir
  meðferðina.
  Prófunar

áfangarnir
 samanstanda
 af
 Ashworth
 skölun
 (klínískt
 mat
 á
 síspennu),
 mat
 á

skjálfta
 eða
 krampakippum
 í
 fótum
 (e.
 clonus),
 10-­‐metra
 göngupróf
 ef
 færni

einstaklingsins
  leyfir,
  raflífeðlisfræðilegum
  athugunum
  með
  upptöku

vöðvarafrits
  og
  Wartenberg
  sveiflupróf
  sem
  ákvarðar
  tölulega
  stærðargráðu

síspennunnar.
 Áhrif
 meðferðarinnar
 á
 síspennu
 var
 svo
 metin
 með
 því
 að
 bera

saman
 niðurstöður
 úr
 prófunum
 1
 og
 2
 og
 niðurstöður
 úr
 prófunum
 3
 voru

bornar
 saman
 við
 upphafs
 niðurstöðurnar
 til
 að
 ákvarða
 hvort
 áhrifin
 vari
 í
 tvo

tíma
 að
 lokinni
 raförvun.

  Niðurstöður:
 Niðurstöður
 úr
 sveifluprófinu
 sýndu
 minnkun
 á
 síspennu
 hjá

fjórum
  einstaklingum
  eftir
  meðferðina.
  Hjá
  hinum
  einstaklingunum
  voru

meðalgildin
 úr
 sveifluprófinu
 í
 fyrsta
 prófunar
 áfanganum
 ≥
 1
 sem
 lýsir
 ástandi

án
 síspennu.
 Engu
 að
 síður
 var
 marktækur
 munur
 á
 samræmdri
 vöðvavirkni

allra
 vöðvahópa
 á
 milli
 prófana
 fyrir
 og
 eftir
 raförvun
 hjá
 öllum
 þátttakendum

sem
 bendir
 til
 lækkunar
 síspennu.
 Niðurstöðurnar
 sýndu
 einnig
 bætta
 hreyfigetu

og
 betri
 stjórn.

  Ályktun:
 Áhrif
 yfirborðsraförvunar
 á
 mænu
 (tSCS)
 á
 síspennu
 er
 hliðstæð

mænuraförvunar
  með
  ígræddum
  rafskautum
  (e.
  epidural
  SCS).
  Bendir
  það

sterklega
 til
 að
 báðar
 þessar
 aðferðir
 örvi
 áþekkar
 taugarásir.
 Af
 niðurstöðunum

getum
 við
 dregið
 þá
 ályktun
 að
 notkun
 þessarar
 aðferðar,
 mænuraförvun
 með

yfirborðsrafskautum
 með
 lágum
 styrk,
 50
 Hz,
 í
 30
 mínútur
 dregur
 úr
 síspennu

bæði
 hjá
 einstaklingum
 með
 alskaða
 og
 hlutskaða
 á
 mænu.
 Hjá
 þátttakendum

með
 hlutskaða
 sýndum
 við
 fram
 á
 færnibætandi
 áhrifa
 með
 betri
 viljastýrðri

stjórn
 á
 hreyfingum
 vegna
 minni
 síspennu.

Lykilorð:
 Mænuraförvun;
 mænuskaði;
 síspenna;
 Wartenberg
 sveiflupróf;

Ashworth
 skölun.

  ii
Evaluation of tSCS treatment
for the alleviation of lower limb spasticity
Halla Kristín Guðfinnsdóttir
60 ECTS thesis submitted to the School of Science and Engineering
at Reykjavík University in partial fulfillment
of the requirements for the degree of
Master of Science in Biomedical Engineering

January 2016

Student:

Halla Kristín Guðfinnsdóttir

Supervisor(s):

Þórður Helgason

Guðbjörg Kristín Ludvigsdóttir

Examiner:

Stefán B. Sigurðsson

  iii
Preface

This
  thesis
  work
  is
  part
  of
  a
  joint
  study
  with
  Reykjavik
  University
  and

Landspitali
 University
 Hospital
 prepared
 in
 collaboration
 with
 Austrian
 partners

at
 the
 Medical
 University
 of
 Vienna
 (contact:
 Prof.
 Winfried
 Mayr).

The
 project
 team
 consists
 of:

• Þórður
 Helgason,
 biomedical
 engineer
 at
 Reykjavik
 University
 and.

• Guðbjörg
 Kristín
 Ludvigsdóttir,
 rehabilitation
 specialist
 at
 the

rehabilitation
 center
 at
 Landspitali
 University
 Hospital,
 Grensás.

• Gígja
 Magnúsdóttir,
 physiotherapist
 at
 the
 rehabilitation
 center
 at

Landspitali
 University
 Hospital,
 Grensás.

• Vilborg
 Guðmundsdóttir,
 physiotherapist
 at
 the
 rehabilitation
 center
 at

Landspitali
 University
 Hospital,
 Grensás.

• José
 Luis
 Vargas
 Luna,
 post-­‐doc
 at
 Reykjavik
 University
 and
 Landspitali

University
 Hospital.

• Halla
 Kristín
 Guðfinnsdóttir,
 master
 student
 in
 biomedical
 engineering
 at

Reykjavik
 University

  iv
Table
 of
 Contents

ABSTRACT:
 .........................................................................................................................................
 I

ÚTDRÁTTUR
 –
 MAT
 Á
 ÁHRIFUM
 MÆNURAFÖRVUNAR
 Á
 SÍSPENNU
 .............................
 II

SIGNATURE
 PAGE
 ..........................................................................................................................
 III

PREFACE
 ...........................................................................................................................................
 IV

LIST
 OF
 TABLES
 ............................................................................................................................
 VII

LIST
 OF
 FIGURES
 .........................................................................................................................
 VIII

INTRODUCTION
 ...............................................................................................................................
 1

GENERAL
 ANATOMICAL
 AND
 PHYSIOLOGICAL
 PRINCIPLES
 OF
 THE
 SPINE
 .............................................
 1

The
 Spinal
 Cord
 ..............................................................................................................................................
 2

Spinal
 Nerves
 and
 Roots

 ..........................................................................................................................
 4

Spinal
 Reflexes
 ................................................................................................................................................
 5

PATHOPHYSIOLOGY
 OF
 SPINAL
 CORD
 INJURY
 ..............................................................................................
 6

Concepts
 of
 Primary
 Injury
 .......................................................................................................................
 6

Concepts
 of
 Secondary
 Injury
 ..................................................................................................................
 7

SPASTICITY
 .........................................................................................................................................................
 7

Pathophysiology
 of
 Spasticity
 ..................................................................................................................
 9

Intrinsic
 Tonic
 Spasticity
 ...........................................................................................................................
 9

Intrinsic
 Phasic
 Spasticity
 ......................................................................................................................
 10

Extrinsic
 Spasticity
 ....................................................................................................................................
 10

SPASTICITY
 ASSESSMENTS
 .............................................................................................................................
 10

The
 Ashworth
 and
 Modified
 Ashworth
 Scales
 ...............................................................................
 11

Biomechanical
 Methods
 ..........................................................................................................................
 12

Wartenberg
 Pendulum
 Test
 ..................................................................................................................
 12

Electrophysiological
 Methods
 -­‐
 Brain
 Motor
 Control
 Assessment
 (BMCA)
 ......................
 13

MANAGEMENT
 OF
 SPASTICITY
 -­‐
 TREATMENT
 ALTERNATIVES
 ...............................................................
 14

Physical
 Interventions
 .............................................................................................................................
 14

Pharmaceutical
 Interventions
 .............................................................................................................
 14

Intrathecal
 Baclofen
 .................................................................................................................................
 15

Injection
 Interventions
 ............................................................................................................................
 15

Surgical
 interventions
 ..............................................................................................................................
 15

ELECTRICAL
 STIMULATION
 FOR
 THE
 REDUCTION
 OF
 SPASTICITY
 .........................................................
 16

Electrical
 Stimulation
 of
 Muscles
 ........................................................................................................
 16

  v
Electrical
 Stimulation
 of
 Peripheral
 Nerves
 ..................................................................................
 17

Electrical
 Spinal
 Cord
 Stimulation
 .....................................................................................................
 17

TRANSCUTANEOUS
 SPINAL
 CORD
 STIMULATION
 ......................................................................................
 19

METHODOLOGY
 .............................................................................................................................
 21

CLINICAL
 DATA
 ................................................................................................................................................
 21

STUDY
 PROTOCOL
 ...........................................................................................................................................
 22

DATA
 COLLECTION
 ..........................................................................................................................................
 24

DATA
 ANALYSIS
 ...............................................................................................................................................
 25

RESULTS
 ...........................................................................................................................................
 27

EFFECTS
 OF
 TSCS
 ON
 INTRINSIC
 TONIC
 SPASTICITY
 .................................................................................
 27

EFFECTS
 OF
 TSCS
 ON
 INTRINSIC
 PHASIC
 SPASTICITY
 ...............................................................................
 29

EFFECTS
 OF
 TSCS
 ON
 EXTRINSIC
 SPASTICITY
 ............................................................................................
 32

EFFECTS
 OF
 TSCS
 ON
 MOTOR
 CONTROL
 .....................................................................................................
 35

REPORTED
 EFFECTS
 OF
 TSCS
 FROM
 SUBJECTS
 ..........................................................................................
 39

DISCUSSION
 .....................................................................................................................................
 40

CONCLUSION
 ...................................................................................................................................
 43

REFERENCES
 ...................................................................................................................................
 44

APPENDIX
 I
 –
 ASIA
 IMPAIRMENT
 SCALE
 (AIS)
 ....................................................................
 51

APPENDIX
 II
 –
 WALKING
 INDEX
 FOR
 SPINAL
 CORD
 INJURY
 (WISCI
 II)
 .......................
 53

APPENDIX
 III
 –
 PROTOCOL
 ........................................................................................................
 54

APPENDIX
 IV
 –
 ASSESSMENT
 FORM
 ........................................................................................
 57

APPENDIX
 V
 –
 WARTENBERG
 PENDULUM
 RESULTS
 .........................................................
 60

APPENDIX
 VI
 –
 WALKING
 TEST
 RESULTS
 (10
 M)
 ...............................................................
 64

APPENDIX
 VII
 –
 QUESTIONNAIRE
 ............................................................................................
 65

  vi
List
 of
 Tables

Table
 1.
 Mechanical
 Forces
 Related
 To
 Primary
 Injury
 [3
 p.
 11].
 ...................................................................
 6

Table
 2.
 The
 Ashworth
 and
 Modified
 Ashworth
 scales
 [7],
 [46],
 [48].
 .......................................................
 11

Table
 3.
 Characteristics
 of
 subjects
 ............................................................................................................................
 21

Table
 4.
 Overall
 summary
 of
 the
 spasticity
 evaluation.
 Shows
 what
 kind
 of
 spasticity
 is
 present

for
 each
 leg
 and
 the
 effects
 of
 tSCS
 on
 the
 spasticity
 in
 assessments
 2
 and
 3
 (ê
 spasticity

reduces,
 é
 Spasticity
 increases,
 ±
 means
 that
 the
 effects
 vary
 between
 muscles).
 ..................
 27

Table
 5.
 Average
 spasticity
 index
 R
 from
 the
 Wartenberg
 pendulum
 test
 for
 all
 subjects*
 ..........
 28

2n,
Table
 6.
 Average
 spasticity
 index
 R
 from
 the
 Wartenberg
 pendulum
 test
 for
 subjects
 with
 R <

2n, 2n
1
 in
 the
 first
 assessment*.
 ...................................................................................................................................
 28

Table
 7.
 Summary
 of
 results
 related
 to
 intrinsic
 tonic
 spasticity.
 Spasticity
 index
 R ,
 and
 average

2n
EMG
 activity
 detected
 during
 the
 Wartenberg
 pendulum
 test.
 The
 first
 line
 of
 each
 subject

shows
 the
 Spasticity
 index
 R ,
 the
 mean
 (M)
 is
 the
 average
 of
 index
 out
 of
 3
 repetitions.
 For

2n
the
 muscle
 activity
 the
 mean
 (M)
 is
 the
 average
 Vrms
 value
 [μV].
 The
 mean
 values
 from

assessments
 2
 and
 3
 (nM)
 are
 normalized
 to
 the
 average
 in
 assessment
 1.
 ................................
 28

Table
 8.
 Summary
 of
 results
 related
 to
 intrinsic
 phasic
 spasticity.
 Scores
 from
 the
 Ashworth
 scale

(AS),
 counts
 of
 clonus
 beats
 (CL)
 and
 average
 EMG
 activity
 of
 each
 muscle
 during
 BMCA5.

The
 mean
 value
 (M)
 of
 the
 Ashwrtoh
 scale
 is
 the
 average
 score
 of
 each
 leg.
 Continuous

clonus
 is
 numerically
 represented
 by
 10
 beats.
 For
 the
 muscle
 activity
 the
 mean
 (M)
 is
 the

average
 Vrms
 value.
 The
 mean
 values
 from
 assessments
 2
 and
 3
 (nM)
 are
 normalized
 to
 the

average
 in
 assessment
 1.
 .....................................................................................................................................
 29

Table
 9.
 Summary
 of
 results
 related
 to
 extrinsic
 spasticity.
 Average
 EMG
 activity
 of
 each
 muscle

during
 BMCA6.
 For
 the
 muscle
 activity
 the
 mean
 (M)
 is
 the
 average
 Vrms
 value
 [μV].
 The

mean
 values
 from
 assessments
 2
 and
 3
 (nM)
 are
 normalized
 to
 the
 average
 in
 assessment
 1.

 ........................................................................................................................................................................................
 32

Table
 10.
 Summary
 of
 results
 related
 to
 the
 effects
 on
 motor
 control.
 Times
 during
 the
 walking

tests
 and
 average
 EMG
 activity
 of
 each
 muscle
 during
 BMCA7.
 For
 the
 walking
 times,
 the

first
 mean
 is
 the
 average
 time
 [s]
 for
 the
 first
 assessment
 and
 the
 mean
 values
 from

assessments
 2
 and
 3
 (nM)
 are
 normalized
 to
 the
 average
 in
 assessment
 1.
 For
 the
 muscle

activity
 the
 mean
 (M)
 is
 the
 average
 Vrms
 value
 [μV]
 and
 the
 mean
 values
 from

assessments
 2
 and
 3
 (nM)
 are
 also
 normalized
 to
 the
 average
 in
 assessment
 1.
 .......................
 36

Table
 11.
 Results
 from
 10-­‐m
 walking
 test
 for
 subjects
 S4-­‐S6.
 ........................................................................
 36

Table
 12.
 Walking
 Index
 for
 Spinal
 Cord
 Injury
 (WISCI
 II)
 [102]
 .................................................................
 53

Table
 13.
 Walking
 test
 results.
 Time
 in
 seconds
 during
 10
 m
 walking
 test.

 Mean
 values
 for

assessments
 2
 and
 3
 are
 normalized
 to
 the
 average
 in
 assessment
 1.
 ............................................
 64

  vii
List
 of
 Figures

Figure
 1.
 The
 vertebral
 column
 seen
 from
 three
 different
 views.
 A.
 Lateral
 view.
 B.
 Anterior
 view.

C.
 Posterior
 view.
 [1,
 p.
 17-­‐18].
 ...........................................................................................................................
 1

Figure
 2.
 The
 twelfth
 thoracic
 vertebrae.
 A.
 Superior
 view.
 B.
 Inferior
 view.
 C.
 Lateral
 view.
 [1
 p.

228-­‐230].
 ......................................................................................................................................................................
 2

Figure
 3.
 Gross
 anatomy
 of
 the
 spinal
 cord
 with
 relationships
 to
 associated
 bony
 structures
 and

other
 body
 parts.
 The
 vertebrae
 are
 color
 coded
 in
 accordance
 to
 the
 various
 spinal
 levels.

The
 axial
 spinal
 sections
 on
 the
 left
 represents
 each
 spinal
 level
 and
 show
 the
 distribution

of
 the
 white
 and
 gray
 matter
 [4
 p.
 5].
 ..............................................................................................................
 3

Figure
 4.
 The
 anatomy
 of
 a
 single
 thoracic
 segment
 A.
 The
 general
 anatomical
 relationships

between
 a
 spinal
 segment,
 the
 meninges,
 the
 dorsal
 an
 ventral
 roots
 and
 associated
 bony

structures
 of
 a
 typical
 thoracic
 vertebrae.
 B.
 Shows
 typical
 ascending
 and
 descending
 tracts

where
 sensory
 pathways
 are
 blue
 and
 motor
 pathways
 in
 red.
 Only
 one
 side
 of
 the
 cord
 is

represented
 but
 the
 same
 fiber
 tracts
 are
 also
 on
 the
 other
 side
 [4
 p.
 6].
 .......................................
 4

Figure
 5.
 Transcutaneous
 spinal
 cord
 stimulation
 with
 the
 stimulation
 and
 reference
 electrodes

over
 the
 back
 and
 abdomen,
 respectively,
 and
 their
 positions
 with
 respect
 to
 the
 spine
 and

lumbosacral
 spinal
 cord
 [52
 p.
 231],
 [81],
 [90].
 ........................................................................................
 19

Figure
 6.
 Neuroanatomy
 relevant
 for
 transcutaneous
 spinal
 cord
 stimulation.
 Cross-­‐section
 (A,B)

and
 side-­‐view
 (C,D)
 drawings
 of
 posterior
 roots
 with
 respect
 the
 lumbosacral
 spinal
 cord

and
 spine.
 All
 large-­‐
 and
 medium-­‐diameter
 fibers
 from
 muscles,
 joints,
 and
 skins
 of
 the

lower
 extremities
 enter
 the
 lumbar
 and
 upper
 sacral
 spinal
 cord
 within
 an
 extent
 of
 few
 a

centimeters
 and
 can
 thus
 be
 activated
 with
 a
 single
 pulse
 [52
 p.
 237].
 .........................................
 20

Figure
 7.
 Graphical
 representation
 of
 the
 four
 stages
 of
 the
 study
 protocol
 ...........................................
 23

Figure
 8.
 The
 set
 up
 of
 the
 equipment’s
 used
 in
 this
 study.
 .............................................................................
 25

Figure
 9.
 EMG
 activity
 (blue)
 of
 triceps
 surae
 and
 tibialis
 anterior
 during
 BMCA5
 of
 the
 left
 leg
 of

S3.

 BMCA5:
 Manual
 elicitation
 of
 ankle
 clonus
 by
 rapid
 stretch
 of
 the
 Achilles
 tendon.
 The

green
 area
 marks
 the
 timespan
 of
 the
 event.
 .............................................................................................
 31

Figure
 10.
 EMG
 activity
 (blue)
 of
 left
 triceps
 surae,
 tibialis
 anterior
 and
 hamstring
 during
 BMCA5

of
 the
 left
 leg
 of
 S8.
 BMCA5:
 Manual
 elicitation
 of
 ankle
 clonus
 by
 rapid
 stretch
 of
 the

Achilles
 tendon.
 The
 green
 area
 marks
 the
 timespan
 of
 the
 event.
 ..................................................
 31

Figure
 11.
 EMG
 activity
 (blue)
 of
 left
 quadriceps,
 hamstring,
 tibialis
 anterior,
 triceps
 surae
 and

adductors
 during
 BMCA6
 of
 the
 left
 leg
 of
 subject
 S3.
 BMCA6:
 Manual
 elicitation
 of
 foot

withdrawal
 by
 non-­‐noxious
 mechanical
 plantar
 stimulation
 with
 a
 blunt
 rod
 (Babinski

reflex).

 The
 green
 area
 marks
 the
 timespan
 of
 the
 event.
 ...................................................................
 33

Figure
 12.
 EMG
 activity
 (blue)
 of
 right
 quadriceps,
 tibialis
 anterior
 and
 adductors
 during
 BMCA6

of
 the
 right
 leg
 of
 subject
 S9.
 BMCA6:
 Manual
 elicitation
 of
 foot
 withdrawal
 by
 non-­‐noxious

mechanical
 plantar
 stimulation
 with
 a
 blunt
 rod
 (Babinski).
 The
 green
 area
 marks
 the

timespan
 of
 the
 event.
 ..........................................................................................................................................
 34

Figure
 13.
 EMG
 activity
 (blue)
 of
 left
 quadriceps,
 hamstring,
 tibialis
 anterior,
 triceps
 surae
 and

adductors
 during
 BMCA6
 of
 the
 left
 leg
 of
 subject
 S8.
 BMCA6:
 Manual
 elicitation
 of
 foot

withdrawal
 by
 non-­‐noxious
 mechanical
 plantar
 stimulation
 with
 a
 blunt
 rod
 (Babinski

reflex).
 The
 green
 area
 marks
 the
 timespan
 of
 the
 events,
 the
 figure
 shows
 two
 repetitions.

 ........................................................................................................................................................................................
 34

Figure
 14.
 EMG
 activity
 (blue)
 of
 right
 quadriceps,
 hamstring,
 tibialis
 anterior,
 triceps
 surae
 and

adductors
 during
 BMCA6
 of
 the
 right
 leg
 of
 subject
 S8.
 BMCA6:
 Manual
 elicitation
 of
 foot

  viii