Oxford University Press eBooks,
Journal Year:
2025,
Volume and Issue:
unknown, P. 26 - 43
Published: April 1, 2025
Abstract
The
equilibrium-point
(EP)
hypothesis
assumes
that
the
neural
control
of
a
muscle
is
adequately
described
as
change
in
stretch
reflex
threshold
(λ)
leading
to
shift
EP—a
combination
length
and
force
when
it
equilibrium
with
external
load.
This
variable
associated
subthreshold
depolarization
alpha-motoneuronal
membrane.
A
λ
can
lead
movement,
production,
or
both.
For
joint
one
kinematic
degree
freedom,
be
two
basic
commands,
reciprocal
coactivation
(R-
C-commands).
R-command
defines
value
angle
net
moments
are
balanced
absence
C-command
spatial
range
both
groups
active
simultaneously.
An
alternative
version,
alpha-model,
was
developed
based
on
observations
deafferented
animals.
Oxford University Press eBooks,
Journal Year:
2025,
Volume and Issue:
unknown, P. 44 - 57
Published: April 1, 2025
Abstract
The
idea
of
the
brain
directly
programming
peripheral
variables,
such
as
forces,
displacements,
and
muscle
activations,
is
deeply
rooted
in
classical
mechanics.
It
has
evolved
under
names
engrams,
generalized
motor
programs,
control
with
activation
patterns
into
current
version
known
“internal
models.”
In
particular,
dual-strategy
pulse-step
hypotheses
were
developed
to
account
for
certain
features
electromyographic
during
single-joint
movements
force
production
tasks.
Both
ignore
reflex
contributions
activation.
Currently,
this
line
thinking
reflected
synergies
primitives
defined
groups
muscles
parallel
scaling
levels.
Inverse
direct
internal
models
are
assumed
emulate
complex
interactions
within
body
between
environment.
These
ideas
endow
structures
supernatural
abilities
unconstrained
by
laws
nature.
They
incompatible
both
behavioral
physiological
observations.
Oxford University Press eBooks,
Journal Year:
2025,
Volume and Issue:
unknown, P. 231 - 248
Published: April 1, 2025
Abstract
Removing
visual
feedback
on
force
magnitude
by
an
effector
leads
to
slow
drifts,
typically
lower
magnitudes,
which
are
not
reported
the
actor.
Much
faster
drifts
seen
during
external
perturbations
or
fast
voluntary
cyclical
changes.
Force
have
been
viewed
as
a
reflection
of
problems
with
working
memory
unintentional
in
referent
coordinates
agonist
and
antagonist
muscles.
The
latter
view
has
confirmed
several
studies
documenting
coactivation
command
coupled
smaller
reciprocal
command.
Drifts
also
invoked
hand
position
position-holding
tasks
whole-body
sway.
During
production
subset
fingers,
drift
patterns
suggest
index
enslaving
higher
values.
Unintentional
movements
common
compensated
for
presence
salient
feedback.
Oxford University Press eBooks,
Journal Year:
2025,
Volume and Issue:
unknown, P. 201 - 216
Published: April 1, 2025
Abstract
Postural
tasks
can
be
defined
as
those
involving
stabilization
of
a
geometrical
body
characteristic.
During
standing,
humans
show
spontaneous
sway,
which
consists
at
least
two
components,
rambling
(equilibrium
trajectory,
likely
supraspinal)
and
trembling
(oscillation
about
rambling,
getting
contributions
from
mechanical
factors
spinal
loops).
Vertical
posture
is
protected
by
number
feedforward
(anticipatory
synergy
adjustments)
feedback
mechanisms.
External
perturbations
lead
to
involuntary
posture-stabilizing
reactions,
while
voluntary
movements
do
not—the
posture-movement
paradox.
The
paradox
solved
naturally
within
the
theory
control
with
spatial
referent
coordinates.
Standing
controlled
setting
orientation
coactivation
command.
It
associated
multi-muscle
synergies.
Excessive
muscle
detrimental
for
postural
stability.
Step
initiation
early
adjustments.
Locomotion
based
on
central
pattern
generators
receiving
inputs
both
supraspinal
structures
reflex
loops.
Oxford University Press eBooks,
Journal Year:
2025,
Volume and Issue:
unknown, P. 217 - 228
Published: April 1, 2025
Abstract
Perception
can
be
viewed
as
a
process
of
measurement
salient
physical
variables.
Peripheral
sensory
endings
provide
ambiguous
information
on
local
mechanical
They
are
interpreted
within
the
frame
reference
specified
by
neural
command,
which
defines
referent
coordinate
for
effector.
The
stability
percepts
reflects
existence
an
iso-perceptual
manifold
in
high-dimensional
(abundant)
efferent-afferent
space.
Motion
along
this
manifold,
example,
during
agonist-antagonist
coactivation,
leads
to
perceptual
equivalence.
High-frequency
muscle
vibration
induces
many
motor
and
phenomena
including
illusions
both
kinematic
kinetic
Their
patterns
suggest
that
changes
afferent
efferent
components
perception.
Only
some
accounted
direct
effects
primary
spindle
endings.
Illusions
also
affected
constraints
forbid
associated
with
violations
body
anatomical
integrity.
Oxford University Press eBooks,
Journal Year:
2025,
Volume and Issue:
unknown, P. 26 - 43
Published: April 1, 2025
Abstract
The
equilibrium-point
(EP)
hypothesis
assumes
that
the
neural
control
of
a
muscle
is
adequately
described
as
change
in
stretch
reflex
threshold
(λ)
leading
to
shift
EP—a
combination
length
and
force
when
it
equilibrium
with
external
load.
This
variable
associated
subthreshold
depolarization
alpha-motoneuronal
membrane.
A
λ
can
lead
movement,
production,
or
both.
For
joint
one
kinematic
degree
freedom,
be
two
basic
commands,
reciprocal
coactivation
(R-
C-commands).
R-command
defines
value
angle
net
moments
are
balanced
absence
C-command
spatial
range
both
groups
active
simultaneously.
An
alternative
version,
alpha-model,
was
developed
based
on
observations
deafferented
animals.
