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Table 5–2. Properties of the Three Movement Systems
Property Reflex Automatic Voluntary
Mediating pathways Spinal cord Brainstem and subcortical Brainstem and cortical
Mode of activation External stimulus External stimulus Self-generated or
Movement Systems
external stimulus
Response properties Localized to point of
stimulus and highly
stereotyped
Role in posture control Regulate muscle forces Coordinate movements
Response times Fixed at 40 msec Fixed at 100 msec Varies with difficulty,
variety of patterns is almost limitless, in theory at least.
When elicited by external stimuli, voluntary movement latencies are 150 msec under the simplest and
most practiced conditions. Latencies can be substantially longer when the task is novel, involves multiple
decisions, or is performed in the presence of distractions (Nashner & Cordo, 1981). When a freely standing person exerts a voluntary force against an external
object, automatic and voluntary activities are closely
coordinated to provide a stable base of support for the
voluntary movement (Belenkii, Gurfinkel, & Paltsev,
1967; Nashner & Cordo, 1981). In these instances, auto-
Coordinated among leg
and trunk muscles, and
stereotyped but adaptable
across joints
Limitless variety
Generate purposeful
behaviors
150+ msec
1979). For example, forward movements are triggered
by backward COG displacements.
The amplitudes of the automatic movements
are related to not only the intensity of the triggering
somatosensory stimulus (Diener, Horak, & Nashner,
1988) but also to visual and vestibular inputs, and to
the individual’s past experiences (Nashner, 1976; Nashner & Berthoz, 1978; Shupert et al., 1988). The pattern
of movement response among leg and lower trunk
muscles, in contrast, is determined not by the triggering stimulus but by the configuration of the support
surface and the previous experience of the individual.
matic postural reactions occur first, and the onset of the
voluntary component is delayed accordingly (Nashner
& Cordo, 1981).
COORDINATION OF AUTOMATIC
POSTURAL
MOVEMENTS
Automatic Postural Movements
When an automatic postural movement is initiated by a
mechanical stimulus, the onset of muscular EMG activity occurs within 90 to 100 msec, and the resulting patterns of activation among leg and lower trunk muscles
are directionally specific and relatively stereotyped.
Active forces are delayed an additional 20 to 40
due to the delay between muscle electrical activation
and force generation (Bawa & Stein, 1976).
Local somatosensory input from the feet and
ankle joints is by itself sufficient to trigger an automatic postural movement (Horak, Nashner, & Diener,
1990). The direction of the automatic movement is also
determined by the triggering somatosensory stimulus
(Horak & Nashner, 1986; Nashner, 1977; Nashner et al.,
msec
Biomechanics of Coordinated Movement
The major joint and muscle systems controlling the
COG during standing are illustrated in Figure 5–5.
Postural movements involve the coordinated actions
of the ankle, knee, hip joints, and frequently the neck.
The motions about each of these joints, however, are not
determined simply by the muscles acting directly about
the joint. This is because leg and trunk muscles also
exert indirect forces on neighboring joints through the
inertial interaction forces among body segments (Nashner, 1985a; Nashner & McCollum, 1985). For example,
when the ankle muscles contract to extend the lower
leg segments backward, the hips will flex unless thigh
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and lower trunk muscles are activated to stabilize these
joints. The hips will flex in the absence of additional
stabilizing forces, because the inertia of the trunk tends
to make its movements lag behind those of the legs.
figure 5–5. Functional anatomy of the major joint and
muscle systems controlling movements of the body’s
COG during standing balance. From Handbook of Bal-
ance Function Testing, Jacobson et al., 1997.
Because of the indirect inertial effects of muscular
forces, the function of leg and trunk muscles during
posture control can differ quite dramatically from their
traditional anatomic classification, as summarized in
Table 5–3. When a person is standing on a rigid surface, contraction of the tibialis anterior (anatomically
classified as an ankle dorsiflexor) also causes knee flexion, even though there is no anatomic insertion of this
muscle at the knee. As dorsiflexion of the ankle moves
the lower leg forward, inertia causes the thigh to lag
behind and the knee flexes as a result. Although the
gastrocnemius is anatomically classified as an ankle
extensor and knee flexor, its functional effect on the
knee during standing is extension rather than flexion.
The knee extends because of inertial interactions similar to the others mentioned.
Contractions of thigh and lower trunk muscles
exert similar indirect effects on the knee and ankle
joints. The quadriceps muscle is not only a hip flexor
and knee extensor by direct action, but also an ankle
extensor by indirect action. The hamstring muscle is an
indirect ankle flexor in addition to its direct knee flexor
and hip extensor functions.
One common example of an abnormal movement
pattern is the destabilization of a proximal knee or hip
joint during postural movement. This problem is often
called proximal joint instability. While it is tempting
to attribute an unstable knee or hip joint to weakness
or inactivity in the muscles acting directly about these
joints, the instability can also be caused by the indirect
effects of delayed ankle muscle activation (Nashner,
Shumway-Cook, & Marin, 1983).
table 5–3. Functional Anatomy of Muscles Involved in Balance Movements
Joint Anatomic Functional Anatomic Functional
Hip Paraspinals
Knee Quadriceps Paraspinals
Ankle Gastrocnemius Abdominals
Hamstrings
Extension Flexion
Paraspinals
Hamstrings
Tibialis Gastrocnemius
Quadriceps
Gastrocnemius
Quadriceps
Gastrocnemius
Abdominal
Quadriceps
Hamstrings
Gastrocnemius
Tibialis Paraspinals
Abdominals
Quadriceps
Abdominals
Hamstrings
Tibialis
Hamstrings
Tibialis
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Coordination of Postural
Movements into Strategies
When a person’s balance is disrupted by an external
perturbation, one or a combination of three different strategies can be used to coordinate movement
of the COG back to a balanced position. Properties of
the three strategies are reviewed in Figure 5–6. A step
or stumbling reaction is the only movement strategy
effective in preventing a fall when the perturbation displaces the COG beyond the LOS perimeter. When the
COG remains within the LOS, two different strategies
or combinations of strategies can be used to move the
COG while maintaining the initial placement of the feet
on the support surface.
Ankle Strategy
The ankle strategy shifts the COG while maintaining
the placement of the feet by rotating the body as an
approximately rigid mass about the ankle joints, as
shown in Figure 5–6. This is accomplished by contracting the ankle joint muscles to generate torque about
the ankle joints. Contractions of thigh and lower trunk
muscles prevent destabilization of these proximal joints
due to the indirect effects of the ankle muscles on the
proximal joints (see Table 5–3).
Ankle movements are generated by EMG responses,
which begin at 90 to 100 msec in the directionally
appropriate ankle joint muscles, specifically gastrocnemius muscles resisting forward COG displacements
and tibialis anterior backward COG displacements
(Horak & Nashner, 1986; Nashner, 1977; Nashner et al.,
1979). Electromyographic activity begins in the ankle
joint muscle and then radiates 10 to 30 msec later to
the thigh and then to the lower trunk muscles on the
same dorsal or ventral aspect of the body. The thigh
and lower trunk muscle contractions stabilize the knees
and hips as the body rotates about the ankles. Activation of the ankle muscles provides proximal muscles
with a stable movement base.
Hip Strategy
Movements organized into the hip strategy are centered
about the hip joints with smaller opposing ankle joint
rotations, as shown in Figure 5–6. When hip rotations
are sufficiently rapid, the COG shifts opposite to the
direction of the hip due to the trunk inertial generating
horizontal (shear) force against the support surface.
Hip strategy movements are generated by activation of the directionally appropriate thigh and lower
trunk muscles at 85 to 95 msec latencies (Horak &
Nashner, 1986). Quadriceps and abdominal muscles
are activated to flex the hips and move the COG backward. The knee remains relatively stable because these
two muscles have opposite functional effects about this
joint (see Table 5–3). Paraspinal and hamstring activation extends the hips and moves the COG backward.
Opposing functional effects of these two muscles also
stabilize the knees. During movements in both directions, the ankle muscles are relatively inactive.
Appropriate Use of Postural
Movement Strategies
The relative effectiveness of ankle, hip, and stepping
strategies in repositioning the COG over the base of support depends on the configuration of the base of support,
Figure 5–6. Three strategies for moving the COG relative to the base
of support during postural sway, and their functional properties. From
Handbook of Balance Function Testing, Jacobson et al., 1997.
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the COG alignment in relation to the LOS, and the speed
(frequency) of the required postural movement (Horak
& Nashner, 1986; McCollum, Horak, & Nashner, 1984;
Nashner & McCollum, 1985). For example, the ankle
strategy is most effective in executing relatively slow,
low-frequency COG movements when the base of support is firm and the COG is well within the LOS perimeter. The ankle strategy is also effective in maintaining a
static posture with the COG offset from the center.
The amplitude and speed of ankle movements
are biomechanically limited by the torque that can be
exerted about the ankles before the feet lift off the support surface (Nashner et al., 1989). The reader can experience this biomechanical constraint by increasing the
amplitude and frequency of sway about the ankles to
the point where the feet begin to lift off the floor. The
strengths of the ankle joint muscles are not the limiting factors. Gastrocnemius strength is determined by
the force requirements for running and jumping, and
therefore far exceeds the requirements for executing
ankle movements. The maximum force capabilities
of the tibialis anterior muscles, in contrast, are more
closely matched to the requirements for balance. Thus,
ankle joint weakness impairs a person’s use of ankle
movements to recover from backward displacements
of the COG.
Hip movements rely on horizontal shear forces
rather than ankle torques to shift the COG and are
therefore not constrained by ankle torque limitations.
Thus, hip movements are effective when the COG is
positioned near the LOS perimeter, the LOS boundaries are contracted by a narrowed base of support, or the
body is swaying at higher frequencies. The reader can
experience the conditions requiring the use of hip movements by attempting to shift posture slowly while standing on tiptoes or moving rapidly on a firm, flat surface.
Hip movements also have biomechanical limitations in that they cannot produce large shifts in COG
position. In addition, because hip movements rely on
inertial reaction forces, they cannot be used to maintain
balance with the COG offset from the center.
When the COG is displaced beyond the LOS, a
step or stumble is the only effective strategy for preventing a fall. While stepping and stumbling are subject
to fewer biomechanical limitations, they are inefficient,
disruptive, and usually inappropriate when simpler
ankle or hip movements are effective.
1986; McCollum, Horak, & Nashner, 1984). When well
practiced at standing on a particular support surface,
relatively pure examples of the appropriate movement
strategy are observed. In contrast, movements combining the two pure strategies are observed during the initial practice trials while transitioning from one support
surface condition to another.
A recent modeling study based on a double (ankle
and hip) inverted pendulum model of posture control
predicted that intermittent control over the joint stiffness
and the active torque requires less energy and is more
effective in stabilizing the body (Suzuki et al., 2012). Furthermore, the authors’ analysis suggests that ankle, hip,
and mixed strategies are emergent properties depending
on joint stiffnesses rather than central programming.
COORDINATION OF HEAD
BODY MOVEMENTS
AND
Head Movement Strategies
Movements of the head relative to the trunk have a
relatively minor effect on the COG position during
standing. This is because the mass of the head is substantially smaller than that of the trunk. Motions of
the head during postural sway are important, nevertheless, because they have a strong influence on two
of the three principal senses of balance: vision and the
vestibular system. The head and body movement strategies reviewed in Figure 5–7 can affect the ability to
determine the position of the COG accurately during
postural sway (Nashner, 1985b; Shupert et al., 1988).
Trunk-Fixed Strategy
Strategies for coordinating movements of the head relative to the trunk can be classified in three categories:
trunk fixed, gravity fixed, and combinations of the two.
In the trunk-fixed strategy, the head and trunk move as
a unit. The neck muscles stiffen to resist the inertial and
gravitational forces tending to rotate the head opposite
to the trunk. Thus, this strategy fixes movements of the
head to those of the trunk.
Gravity-Fixed Strategy
Selecting the Postural Movement Strategy
Experimental observations suggest that the response
strategies are centrally set in advance depending on the
person’s immediate past experience (Horak & Nashner,
The gravity-fixed strategy rotates the head in opposition
to the trunk so that the head remains level relative to the
gravitational vertical. This strategy requires coordinated
neck and trunk muscular actions to eliminate head
rotations correlated with COG sway while preserving
the linear translational components of head motion.
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INTERACTIONS BETWEEN SENSORY AND
MOTOR COMPONENTS OF BALANCE
Sensory Effects of Body and
Head Movement Strategies
The pattern of ankle, knee, hip, and head movements
strongly influences the visual and vestibular inputs to
balance (Nashner, 1985a). If a person is swaying about
Figure 5 –7. Strategies for moving the head relative to the trunk during
postural sway, and their functional properties.
direction of the gaze.
the gaze direction is disturbed substantially more by the hip than the
ankle strategy. When head position is gravity-fixed, gaze direction is
not disturbed by either strategy. From Handbook of Balance Function
Testing, Jacobson et al., 1997.
Note that when the head position is trunk-fixed,
Visual “rays” show the
the ankles while holding the head fixed to the trunk,
for example, the head and body move as a unit and
the linear and rotational motions of the head and the
body COG are similar. In theory at least, this strategy
simplifies the brain’s task of interpreting input from
the visual and vestibular systems.
Moving the head and body as a unit, however, is
disadvantageous whenever independent head and eye
movements are required, such as maintaining gaze on
an object or scanning the terrain. Without the ability to
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move the head and eyes independently, backward or
forward sway will move the head and eyes up or down,
respectively, and thus away from a desired visual target. The negative impact on vision of the body-fixed
strategy of head control is particularly great during
hip movements, when motions of the trunk are large
and rapid.
Fixing the rotational position of the head relative
to gravity has two potential benefits. First, the eyes are
freer to maintain gaze on objects in the visual surround
with the head fixed in relation to gravity. Second, the
gravity-fixed strategy of head coordination has the
potential for reducing the confusion between linear and
angular accelerations related to balance, a shortcoming
of all inertial-gravitational systems, including the vestibular system. An example of this type of confusion
can be experienced when a jet airliner brakes immediately after touching down on the runway. A passenger
looking straight ahead will sense that the cabin is tilting downward, even to the point of dipping below the
level of the runway. This illusion occurs even though
the plane remains level, because the brain incorrectly
interprets the linear deceleration inputs from the vestibular system as forward tilting.
There is the potential for misinterpretation of tilt
and linear acceleration inputs to the vestibular system
during sway, because the head both tilts and moves linearly (Parker et al., 1985). Fixing the rotational position
of the head relative to gravity reduces the confusion
by eliminating the tilting component. When a gravityfixed strategy is used, linear acceleration can be interpreted as linear head acceleration alone.
This theoretical analysis of the senses suggests
that selection of head and body movement strategies is
based not only on surface conditions and COG position
within the LOS, as described previously, but also on the
need to simplify the interpretation of vestibular input
to balance. There is no conclusive experimental proof
that sensory processes influence a person’s choice of
head and body movement strategies. The following
section describes results with healthy individuals and
patients with sensory balance problems which are consistent with this conclusion.
in Figure 5–7. Analysis of leg, lower trunk, and neck
muscle EMG activity during automatic postural movements indicates that the motions of the head and body
are coordinated at the automatic level of control. During forward automatic hip movements, for example,
rectus abdominus (hip flexor) and sternocleidomastoid
(neck flexor) are simultaneously activated at 90 to 100
msec. The sternocleidomastoid activation prevents the
large nose-up rotation of the head that would occur in
the absence of active head control.
When normal individuals use the ankle strategy,
head and body movements are not tightly coordinated.
Instead, the head moves passively in the direction opposite to the body, rotating nose up and then nose down
in relation to gravity over a range of approximately
10°. These opposing head rotations occur as predicted
by biomechanics in the absence of active head control.
Analysis of leg, lower trunk, and neck muscle EMG
activities during automatic ankle movement confirms
that neck muscle actions are not correlated with those of
the legs and lower trunk (Shupert et al., 1988).
In contrast to normal individuals, patients with
bilateral loss of vestibular inputs avoid hip movements
under all conditions, even though they have no motor
deficits that impair their hip motor control (Shupert
et al., 1988). These patients also tend to fix the position
of the head relative to the trunk. Subjects deprived of
somatosensory inputs from the feet by transient ischemia prefer hip movements under all support surface
conditions, even though the sensory loss does not
impair their ability to execute ankle movements.
Head–body coordination during in-place hip
movements and during running, hopping, and jumping is consistent with the need for head stabilization
during complex movements. As suggested in the section on sensory effects of head and body movement
strategies, the COG position is more difficult to determine from vestibular and visual inputs during complex
movements. This process is simplified by stabilizing
the position of the head relative to gravity.
Voluntary Movements Influence Balance
Integration of Head and Body
Movement Strategies
Head and body movements are coordinated during inplace standing, and when running, jumping, and hopping (Nashner et al., 1988; Pozzo, Berthoz, & Lefort,
1989). During these tasks, the head is approximately
stabilized relative to the gravitational vertical, as shown
A standing person’s voluntary motor activities, as well
as gravity and external perturbing forces, can destabilize balance. Excluding movements having a direct
effect on the base of support (shifting weight, raising
or changing the placement of a foot), the voluntary
actions summarized in Table 5–4 are classified in two
categories based on their effects on balance.
The first category of voluntary actions includes
movements involving manipulation of external objects.
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Table 5–4. Functional Properties of Two Types of Voluntary Actions
Property Object Manipulations Free Body Movements
Voluntary Actions
Effect on center of gravity
Coordination during free
standing
Coordination with the body
supported
Examples Pull or push on object, grasp
Direct equal and opposite force Little if any direct force
Anticipatory postural response
and delayed voluntary onset
Little postural activity and rapid
voluntary onset
and lift object
These actions have the greatest destabilizing effects on
balance. For example, when pulling open a heavy door,
the backward force required to move the door generates an equal and opposite forward force on COG of
the body. If this destabilizing force is not compensated
by an appropriate postural reaction, the person falls
forward into the opening door.
The second category includes voluntary actions
not involving external objects. These actions change
body posture but have only indirect and relatively
minor effects on COG position. Raising an arm from
the side to a forward pointing position, for example,
does not substantially alter the COG position, because
the force required to accelerate the arm forward produces an equal and opposite force accelerating the
trunk slightly backward. The net result is little if any
change in balance.
Students of physics will recognize that voluntary
actions are distinguished based on the presence or
absence of external and internal forces. External forces
have a direct effect on the COG position of a body,
while internal forces acting between body parts tend
to reorient the parts relative to one another with little
net effect on COG position. “Real world” situations,
however, are never quite so simple. Because the body
is supported by contact with a surface, rapid elevations
of an arm can have minor effects on balance.
Coordination of Voluntary and
Automatic Postural Movements
When a freely standing person performs a voluntary
action involving external forces (e.g., pulling on a heavy
external object), an automatic postural movement is
initiated in advance of the voluntary arm movement
to compensate for the disturbance in balance (Belenkii
Less postural activity and rapid
voluntary onset
Little postural activity and rapid
voluntary onset
Lift arm, reach or point
et al., 1967; Cordo & Nashner, 1982; Nashner & Cordo,
1981). The anticipatory automatic postural movement
minimizes any disturbance to balance and provides a
stable base for the voluntary action.
The properties of an anticipatory postural movement depend on the requirements for balance at the
time of the voluntary action. Removing the need to
maintain balance by providing trunk support during
a voluntary action, for example, abolishes the anticipatory postural movement. In this instance, the voluntary action itself can actually be initiated sooner. This
later observation indicates that, to meet the requirements of balance in a freestanding task, voluntary
actions with the potential for disrupting balance are
actively delayed so that a stable base of support is
established first.
CONCLUSIONS
Balance is a multicomponent and highly adaptable control process. When the balance of a healthy individual
is challenged, the sensory inputs determining the COG
position and the pattern of movement correcting the
perturbation depend on the task conditions and the person’s immediate past experience. An individual with
one or more impaired sensory inputs or motor output
components will attempt to compensate by adapting
both the impaired and normally functioning components to best meet the demands of the balance task.
When a patient complains of unsteadiness, the
problem is seldom caused by the absence of balancerelated activities. More frequently, some components
are functioning normally and others abnormally, the
interactions of which lead to functionally inappropriate or ineffective balance responses. Because of these
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multiple interactions, focusing the diagnostic assessment or treatment on isolated component(s) of the balance system is frequently ineffective. In these cases,
understanding the patient’s abnormality requires an
assessment approach that systematically examines all
components and their interactions under a variety of
task conditions. A test battery designed to generate a
systematic description of the patient’s balance problem, called computerized dynamic posturography, is
described in Chapter 15.
referenCes
Aggashyan, R. V., Gurfinkel, V. S., Mamasakhlisov, G. V., &
Elner, A. M. (1973). Changes in spectral and correlation
characteristics of human stabilograms at muscle afferentation disturbance. Agressologie, 14, 5–9.
Allum, J. H. J., Honegger, F., & Pfaltz, C. R. (1989). The role of
stretch and vestibulo-spinal reflexes in the generation of
human equilibrating reactions. In J. H. J. Allum & M. Hulliger (Eds.), Progress in brain research (Vol. 80, pp. 399–409).
New York, NY: Elsevier.
Asslander, L. & Peterka, R.J. (2014). Sensory reweighting
dynamics in human postural control. Journal of Neurophysi-
ology, 111, 1852–1864.
Bawa, P., & Stein, R. B. (1976). Frequency response of human
soleus muscle. Journal of Neurophysiology, 39, 788–793.
Begbie, J. V. (1967). Some problems of postural sway. In A.
V. S. deReuck & J. Knight (Eds.), CIBA Foundation Sym-
posium on myotatic, kinesthetic and vestibular mechanisms
(pp. 80–92). London, UK: Churchill.
Belenkii, V. Y., Gurfinkel, V. S., & Paltsev, Y. I. (1967). On the
elements of voluntary movement control. Biophysics, 12,
135–141.
Black, F. O., & Nashner, L. M. (1984). Vestibulospinal control
differs in patients with reduced versus distorted vestibular function. Acta Oto-Laryngologica, 406, 110–114.
Black, F. O., & Nashner, L. M. (1985). Postural control in four
classes of vestibular abnormalities. In M. Igarashi & F.
O. Black (Eds.), Vestibular and visual control of posture and
locomotor equilibrium (pp. 271–281). Basel, Switzerland:
Karger.
S.
Bles, W., de Jong, J. M. B. V., & de Wit, G. (1984). Somatosen-
sory compensation for loss of labyrinthine function. Acta
Oto-Laryngologica, 97, 213–221.
Brandt, T., Paulus, W., & Straube, A. (1986). Vision and pos-
ture. In W. Bles & T. Brandt (Eds.), Disorders of posture and
gait (pp. 157–175). New York, NY: Elsevier.
Cassadio, M., & Morasso, P. G. (2005) Direct measurement
of ankle stiffness during quiet standing: Implications for
control modelling and clinical application. Gait & Posture,
21, 410–424.
Cordo, P. J., & Nashner, L. M. (1982). Properties of postural
adjustments associated with rapid arm movements. Neu-
rophysiology, 47, 287–302.
Dichgans, J., Held, R., Young, L. R., & Brandt, T. (1972). The
moving visual scenes influence the apparent direction of
gravity. Science, 178, 1217–1219.
Diener, H. C., & Dichgans, J. (1988). On the role of vestibu-
lar, visual, and somatosensory information for dynamic
postural control in humans. In O. Pompeiano & J. H. J.
Allum (Eds.), Progress in brain research (Vol. 76, 253–262).
New York, NY: Elsevier.
Diener, H. C., Dichgans, J., Bacher, B., & Gompf, B. (1984).
Quantification of postural sway in normals and patients
with cerebellar diseases. Electroencephalography Clinical
Neurophysiology, 157, 134–142.
Diener, H. C., Dichgans, J., & Guschlbauer, B. (1986). Role of
visual and static vestibular influences on dynamic posture
control. Human Neurobiology, 5, 105–113.
Diener, H. C., Horak, F. B., & Nashner, L. M. (1988). Influence
of stimulus parameters on human postural responses.
Journal of Neurophysiology, 59, 1888–1895.
Dietz, V., Horstmann, G. A., & Berger, W. (1989). Significance
of proprioceptive mechanisms in the regulation of stance.
In J. H. J. Allum & M. Hulliger (Eds.), Progress in brain
research (Vol. 80, pp. 419–423). New York, NY: Elsevier.
Duncan, P. W., Weiner, D. K., Chandler, J., & Studenski, S.
(1990). Functional reach: A new clinical measure of balance. Gerentology, 45, 192–197.
Evarts, E. V., & Tanjii, J. (1974). Gating of motor cortex reflexes
by prior instruction. Brain Research, 71, 479–494.
Fregly, A. R. (1974). Vestibular ataxia and its measurement
in man. In H. H. Kornhuber (Ed.), Handbook of sensory
physiology (Vol. 6, No. 2, pp. 321–360). Berlin, Germany:
Springer-Verlag.
Gibson, J. J. (1979). The ecological approach to visual perception.
Boston, MA: Houghton Mifflin.
Gurfinkel, V. S., Lipshits, M. I., Mori, S., & Popov, K. E. (1976).
The state of the stretch reflex during quiet standing in
man. In H. Homma (Ed.), Progress in brain research (Vol. 44,
pp. 473–490). New York, NY: Elsevier.
Gurfinkel, V. S., Lipshits, M. I., & Popov, K. Y. (1974). Is the
stretch reflex the main mechanism in the system of regulation of the vertical posture of man? Biophysics, 19, 744–
748.
Gurfinkel, V. S., & Osevets, M. (1972). Dynamics of the verti-
cal posture in man. Biophysics, 17, 496–506.
Hill, V. (1953). The mechanics of active muscle. Proceedings of
the Royal Society of London, 141B, 104–117.
Horak, F. B., & Nashner, L. M. (1986). Central programming
of postural movements: Adaptation to altered support
surface configurations. Neurophysiology, 55, 1369–1381.
Horak, F. B., Nashner, L. M., & Diener, H. C. (1990). Postural
strategies associated with somatosensory and vestibular
loss. Experimental Brain Research, 82, 167–177.
Houk, J. C. (1979). Regulation of stiffness by skeletomotor
reflexes. Annual Review of Physiology, 41, 99–114.
Keshner, E. A., & Kenyan, R. V. (2009). Postural and spatial
orientation driven by virtual reality. Studies in Health Tech-
nology and Informatics, 145, 209–228.
Koozekanani, S. H., Stockwell, C. W., McGhee, R. B., &
Firoozmand, F. (1980). On the role of dynamic models in
102 BAlAnCE FunCtion AssEssmEnt And mAnAgEmEnt
https://t.me/medicina_free
quantitative posturography. IEEE Transactions Biomedical
Engineering, 27, 605–609.
Lee, D. N., & Lishman, J. R. (1975). Visual proprioceptive con-
trol of stance. Journal of Human Movement Studies, 1, 87–95.
Lestienne, F., Soechting, J., & Berthoz, A. (1977). Postural
readjustments induced by linear motion of visual scenes.
Experimental Brain Research, 28, 363–384.
Logan, D., Kiemel T., & Jeka, J. J. (2014). Asymmetric reweight-
ing in human upright stance. PLoS ONE, 9, e100418.
Marsden, C. D., Merton, P. A., & Morton, H. B. (1973). Latency
measurements compatible with a cortical pathway for the
stretch reflex in man. Journal of Physiology, 230, 58–59.
Maurer, C., & Peterka, R. J. (2005). A new interpretation of
spontaneous sway measures based on a simple model
of human postural sway. Journal of Neurophysiology, 93,
189–200.
McCollum, G., Horak, F. B., & Nashner, L. M. (1984). Parsi-
mony in neural calculations for postural movements. In
J. Bloedel, J. Dichgans, & W. Precht (Eds.), Cerebellar func-
tions (pp. 52–66). Berlin, Germany: Springer-Verlag.
McCollum, G., & Leen, T. K. (1989). Form and exploration of
mechanical stability limits in erect stance. Journal of Motor
Behavior, 21, 225–244.
Melville Jones, G., & Watt, D. G. D. (1971). Observations on
the control of stepping and hopping movements in man.
Journal of Physiology, 219, 709–727.
Nashner, L. M. (1976). Adapting reflexes controlling the
human posture. Experimental Brain Research, 26, 59–72.
Nashner, L. M. (1977). Fixed patterns of rapid postural
responses among leg muscles during stance. Experimental
Brain Research, 150, 403–407.
Nashner, L. M. (1985a). Strategies for organization of human
posture. In M. Igarashi & F. O. Black (Eds.), Vestibular and
visual control of posture and locomotor equilibrium (pp. 1–8).
Basel, Switzerland: S. Karger.
Nashner, L. M. (1985b). A functional approach to under-
standing spasticity. In A. Struppler & A. Weindl (Eds.),
Electromyography and evoked potentials (pp. 22–29). Berlin,
Germany: Springer-Verlag.
Nashner, L. M. (1986). The organization of human postural
movements during standing and walking. In S. Grillner, P.
S. G. Stein, & D. G. Stewart (Eds.), Neurobiology of posture
and locomotion (pp. 637–648). London, UK: Macmillan.
Nashner, L. M., & Berthoz, A. (1978). Visual contribution
to rapid motor responses during posture control. Brain
Research, 150, 403–407.
Nashner, L. M., Black, F. O., & Wall, C. (1982). Adaptation
to altered support and visual conditions during stance:
Patients with vestibular deficits. Journal of Neuroscience, 2,
536–544.
Nashner, L. M., & Cordo, P. J. (1981). Relation of automatic
postural responses and reaction-time voluntary movements of human leg muscles. Experimental Brain Research,
43, 395–405.
Nashner, L. M., & Forssberg, H. (1986). Phase-dependent orga-
nization of postural adjustments associated with arm movements while walking. Journal of Neurophysiology, 55, 538–548.
Nashner, L. M., & McCollum, G. (1985). The organization of
human postural movements: A formal basis and experimental synthesis. Behavioral and Brain Sciences, 8, 135–172.
Nashner, L. M., Shumway-Cook, A., & Marin, O. (1983).
Stance posture control in select groups of children with
cerebral palsy: Deficits in sensory organization and
muscular coordination. Experimental Brain Research, 49,
393–409.
Nashner, L. M., Shupert, C. L., & Horak, F. B. (1988). Head-
trunk coordination in the standing posture. In O. Pompeiano & J. H. J. Allum (Eds.), Progress in brain research
(Vol. 76, pp. 243–251). New York, NY: Elsevier.
Nashner, L. M., Shupert, C. L., Horak, F. B., & Black, F. O.
(1989). Organization of posture controls: An analysis of
sensory and mechanical constraints. In J. H. J. Allum & M.
Hulliger (Eds.), Progress in brain research (Vol. 80, pp. 411–
418). New York, NY: Elsevier.
Nashner, L. M., Woollacott, M., & Tuma, G. (1979). Organiza-
tion of rapid responses to postural and locomotorlike perturbations of standing man. Experimental Brain Research,
36, 463–476.
Paloski., W. H., Reschke, M. F., Doxey, D. D., & Harm, D. L.
(1992). Neurosensory adaptation associated with postural
ataxia following space flight. In M. Woollacott & F. Horak
(Eds.), Posture and gait: Control mechanisms (Vol. I, pp. 311–
314). Eugene, OR: University of Oregon Books.
Parker, D. E., Reschke, M. F., Arrott, A. P., Hormick, J. L., &
Lichtenberg, B. K. (1985). Otolith tilt-translation reinterpretation following prolonged weightlessness: Implications
for preflight training. Aviation and Space Environmental
Medicine, 56, 601–606.
Paulus, W. M., Straube, A., & Brandt, T. (1984). Visual stabi-
lization of posture: Physiological stimulus characteristics
and clinical aspects. Brain, 107, 1143–1163.
Paulus, W. M., Straube, A., & Brandt, T. (1987). Visual pos-
tural performance after loss of somatosensory and vestibular function. Journal of Neurology, Neurosurgery and
Psychiatry, 50, 1542–1545.
Pavol, M. J. (2005). Detecting and understanding differences
in postural sway. Journal of Neurophysiology, 93, 20–21.
Peterka, R. J. & Loughlin, P. J. (2004). Dynamic regulation of
sensorimotor integration in human postural control. Jour-
nal of Neurophysiology, 91, 410–423.
Pozzo, T., Berthoz, A., & Lefort, L. (1989). Head kinematics
during various motor tasks in humans. In J. H. J. Allum &
M. Hulliger (Eds.), Progress in brain research (Vol. 80, pp. 377–
383). New York, NY: Elsevier.
Scott, D. E., & Dzendolet, E. (1972). Quantification of sway in
standing humans. Agressologie, 13, 35–40.
Shupert, C. L., Black, F. O., & Horak, F. B. (1988). Coordination
of head and body in response to support surface translations in normals and patients with bilaterally reduced
vestibular function. In B. Amblard, A. Berthoz, & F. Clarac
(Eds.), Posture and gait: Development, adaptation and modula-
tion (pp. 281–289). New York, NY: Elsevier.
Streepey, J. W., Kenyan, R. V., & Keshner, E. A. (2007). Field
of view and base of support width influence postural
5. PrACtiCAl BiomECHAniCs And PHysiology oF BAlAnCE 103
https://t.me/medicina_free
responses to visual stimuli during quiet stance. Gait and
Posture, 25, 49–55.
Suzuki, Y., Nomura, T., Casadio, M., & Morasso, P. (2012).
Intermittent control of ankle, hip, and mixed strategies
during quiet standing: A theoretical proposal based on
a double inverted pendulum model. Journal of Theoretical
Biology, 310, 55–79.
Young, L. R., Oman, C. M., Watt, D. G. D., Money, K. E., & Lich-
tenberg, B. K. (1984). Spatial orientation in weightlessness
and readaptation to earth’s gravity. Science, 225, 202–208.
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