On kinesis, Carson (1985) concludes aptly
with the statement "Kinesis is an undirected
response to stimulation, the response being
movement of all or parts of the body as in
locomotion or stretching". The latter is a
remarkably neglected feature in the study of
behaviour. With attention drawn to certain
aspects of kinesis among the elemental
behavioural needs of animals, this category of
maintenance calls for better attention in
applied ethology. As a component of this,
kinetic activities have been given specific
description in current texts but they have been
neglected in others. One reason may be that
stretching has been perceived as a miscellaneous
variety of singular acts having little relevance
to the applied topics which increasingly relate
to welfare, providing it with its rationale in
large measure.
The situation is different with regard to
poultry in which the usual forms of stretching
are common knowledge.
STRETCHING
Common features
In poultry the common forms of stretching
include vigorous extension of one wing after
another; also common is the action in which,
with one wing being stretched in a backward
direction, the leg on the same side becomes
extended backwards. In addition, there are
periodic upward stretching actions of the head
and neck. In other farm livestock, stretching is
most often seen after rising; these acts have
been described by giving their principal
components: arching of the neck, straightening
of the back and full extension of one or the
other hind leg. Such stretching acts are often
seen in series. Extension of the forelimbs,
singly or together, has been described as a
related exercise. Dogs are commonly seen to
stretch their forelegs forward together, while
depressing the shoulders and back region. Cats
do much of their stretching in the form of,
so-called, "claw-sharpening" acts. In the latter
there is usually a series of alternating
forelimb pulls with the extruded claws anchoring
the paw before being plucked free. This latter
act terminates the singular stretch.
In association with some stretching episodes
yawning may occur among the mammalian subjects
mentioned. In other instances it may occur alone
in the form of slow and maximal extension of the
tempero-mandibular joints. Other localized
stretching can involve the tail and even the
tongue. The eyes may be shut during some forms
of stretching. In contrast, more elaborate
regional stretching is seen in such actions as
partial rotation or deviation of the head and
neck, extension of the carpal or elbow joint and
stiffening of the trunk.
While the concept is of musculature being
stretched, many of the above actions clearly
involve marked joint extension. The
atlanto-occipital joint is subject to
considerable articulation in some of the above
actions. Other major joints which are notably
involved in fully extended articulations are
shoulder, elbow, carpus, stifle and tarsus.
Stretching also occurs in action patterns of
almost identical form in the mammalian species
in such a way as to extend and stiffen the
extremities and, trunk. In such patterns of
stretching the musculature and articulations
involved are, in general, used in striding and
righting behaviour.
Pandiculation
Among the forms of stretching which have
been given varying degrees of attention is one
particular manifestation which has been
overlooked as being a homologue of pandiculation
as recognized in man. The symmetrical,
coordinated stretching and stiffening actions of
the body as one unit is true pandiculation. This
action typically occurs in man and animals
alike, as an exertion which sweeps wavelike
through the subject's'main articular parts,
extending them distally. In each pandiculation
there is a chain of actions, notably of the
head, neck and limbs which are coordinated in
stretching; yawning is sometimes involved among
these articular extensions. Pandiculation is, in
fact, a very characteristic phenomenon with
overall stretching as its core. Modern
neuroethology has shed light on the
physiological background.
The simple form of stretch reflex (myotatic
reflex) is typically monosynaptic in nature. The
overall reflex evidently involves consciousness
and awareness, and permits degrees of voluntary
control. Long latency of this overall sequence
makes it analogous to polysynaptic "postmyotatic
reflexes". Response to muscle stiffness - from
myotatic reflex - is a postmyotatic response.
The postmyotatic response can serve to restore
the limb (and related musculature) to an
original (homeostatic) state. Thus the
postmyotatic response is homeostatic in
formation. This manifestation of homostatic
kinesis therefore indicates its status in
well-being. Its function is to decrease
stiffness and with this there is a
circumstantially evident satisfaction. Myotatic
reflexes apparently serve to increase stiffness
while the postmyotatic can serve to diminish
stiffness.
Pandiculation conforms to the concept of
fixed action pattern in that it has a relatively
fixed pattern of coordination which, while
appearing stereotyped, has variability in
orientation. Being a feature of mammalian
(including human) behaviour the degree of
plasticity is great and fits better under the
concept of modal action pattern. Awareness
influences these acts.
OBSERVATIONS
A. Special features
Pandiculation as a comparative phenomenon
has a core of common characteristics from time
to time, from subject to subject and among many
species. These characteristics can be listed as
follows:
1, extending the arms/forelimbs; 2,
extending the legs/hindlimbs; 3, extending the
head and neck upward or forward; 4, flexing the
vertebral column by depressing it or arching it
regionally; 5, stiffening the trunk; 6,
yawning.
The above features in animal pandiculation
have a high degree of constancy. Among them can
be variations such as absence of yawning or
exertion at only one pole of the body, i.e.
anterior or posterior. Again animal
pandiculation can have symmetry in simultaneous
or alternating extension of limb pairs.
Obviously, all four limbs cannot be easily fully
extended simultaneously in the standing subject,
ALThough they are typically involved in
simultaneous extension in pandiculation when the
animal is lying in lateral recumbency. In this
latter situation the tetanoid form of the
phenomenon is most evident.
Other notable characteristics of
pandiculation in animals include those
given
below:
(a) Polarity. Although the action pattern is
not directed in relation to the environment, it
has direction in relation to its body-base. It
can therefore be recognized as being variously
outstretched, upraised, anterior or
posterior.
(b) Position. Pandiculation can occur in the
two basic positions of upright stance or lateral
recumbency.
(c) Totality. The whole pattern of
pandiculation may occur in a given
manifestation, or recognizable portions of it
may be produced. It can therefore be complete or
partial.
(d) Periodicity. Many occurrences of
pandiculation are in pensomnolent circumstances,
e.g. when the animal is arousing from sleep or
as sleep is being initiated. It often also
occurs at the end of a period of flexed sternal
recumbency. Occurrences are also common, notably
in dogs, when there is a change from inactivity
to exercise. Furthermore, pandiculations may
recur as a series of events in close
succession.
B. Clinical features
(i) Illness. Pandiculation is remarkably
absent in all forms of general illness. Equally
notable is its return to behaviour when the
animal is progressing in convalescence and
returning to a state of health.
(ii) Diagnosis. It is of prognostic value in
appraising a recovery to health. Equally it is
of some diagnostic value in ascertaining a state
of well-being in an animal which is otherwise
clinically sound.
(iii) Age. The complete forms of
pandiculation appear to be shown with greater
frequency in young animals than in older ones.
In the latter, incomplete manifestations are
wore common.
(iv) Confinement. Whereas it appears that
release from confinement or change of locus
often induces pandiculation, it is noted that
the full pattern cannot be reproduced by the
animal until it has sufficient space for the
vigorous bodily extensions which are the main
feature.
(v) Comfort. Clinical subjectivity affirms
that the phenomenon is associated with evident
satisfaction. In the animal's bodily and
behavioural conditions an element of comfort
attainment can be assumed.
The stimulus to pandiculation can be assumed
to be feedback from stiffness. The role of such
feedback in behavioural action has been
comprehensively considered by Miles and Evarts
(1979). In addition, the phenomenon at times may
be in response to a period of asymmetry in
position. Zwislocki (1980) has reviewed the role
of the cochleovestibular apparatus in relation
to relevant circumstances which give grounds to
a supposition that pandiculation has an
antigravity force to it.
An interesting minor feature is eye closure
in this activity. It may be that the eyes are
closed for saccadic suppression, to allow the
voluntary action to be performed without the
opposing system of optomotor signals which could
effectively immobilize the animal. Slow movement
also overcomes any influence from optomotor
feedback aimed at correcting the body's position
when the centre of gravity changes or body
angles are changed.
That the phenomenon is homologous in its
form and circumstances across so many species is
a testimony to its deep evolutionary root.
Further study on its comparative nature could be
rewarding. The value in recognizing this
behaviour as meaningful may now lie in the fact
that it appears to be a sign of well-being. The
latter is an acknowledged state which applied
ethology is attempting to identify. Notice of
this phenomenon may give progress in that
direction.
The body-based character of pandiculation
emphasizes the need for primary space for basic
kinetic output and for general comfort. This is
a point which has been made before but this
matter gives further weight to this case which
is fundamental to welfare.
