Transcriber’s notes:
The text of this book has been preserved as in the original, apart
from repositioning of some footnotes and illustrations closer to the
relevant text. Italic text is denoted by _underscores_.
THE HUMAN FOOT
AND THE
HUMAN HAND.
BY
G. M. HUMPHRY, M.D. F.R.S.
LECTURER ON ANATOMY AND PHYSIOLOGY IN THE
UNIVERSITY OF CAMBRIDGE.
MACMILLAN AND CO.
Cambridge:
AND 23, HENRIETTA STREET, COVENT GARDEN,
London.
1861.
Cambridge:
PRINTED BY C. J. CLAY, M.A.
AT THE UNIVERSITY PRESS.
The following pages originated in two popular Lectures which were
delivered in Cambridge. In the preparation for publication many
additions have been made; but I have thought it best to retain the
original form.
CONTENTS.
THE HUMAN FOOT.
Why are the generality of persons so ignorant of the structure of their
own bodies? p. 1. The dependence of the hand upon the foot, 3.
Principle of “division of Labour” illustrated in the animal world, 4;
and in the function of locomotion, 6.
Structure of Lower Limb, 8. Length of Leg in GIANTS, 9. Bones of
Foot, _ib._ Peculiarity of GREAT TOE, 10. Uniformity in plan, and
dissimilarity in detail seen throughout nature, 13. Homologous parts in
animals, 14. Comparison of Horse’s Leg with Man’s, 15. The ARCH of the
foot, 18; its elasticity greater in the fore part than in the hinder,
21. The Component bones held together by Ligaments, 24. WEAK ANKLE and
FLAT FOOT, 27, 74; time of life at which they occur, 31. Injurious
effects of “High-lows,” 29.
Movements of the FOOT, 33; compared with those of the HEAD, 35.
Nature’s abhorrence of straight lines illustrated by shape of
leg-bone, 37, and by movements of leg upon thigh, 39. Sitting upon the
heel, _ib._ Grecian and Egyptian statuary compared, 40. Relation of
PERFECTION and BEAUTY, 41.
MUSCLES of Leg and Foot, 42. Purpose served by movements of Infants,
46. CLUB-FOOT, 47. Shape of the ankle, 48. Length and direction of the
heel, 50. The CALF, _ib._; characteristic of man, 53. EUROPEAN Leg
and Foot contrasted with NEGRO’S, 51. CHINESE foot, 54. Tendency of
different races to exaggerate their peculiarities, 56. Provision for
enabling balls of toes to adapt themselves to uneven surfaces, 57.
STANDING, 59. BOWING, STOOPING and SQUATTING, 61. WALKING, 62. RUNNING,
64. TROTTING and GALLOPING, 67. Rolling in walking, 69. Sprained ankle,
70. Mode in which foot revolves on the ground, 73. Character shown in
walking, 76. The IDIOT, 80. The DRUNKARD, 81.
Distinctive features of the Human Foot, 82; most marked in highest
races, 91. The TOES of small size and, comparatively, unimportant, 84.
The foot of the ELEPHANT, 86; of the HIPPOPOTAMUS, RHINOCEROS, OX, and
HORSE, 87; of the GORILLA, 88. Proportions of the limbs, 94. Foot and
hand small in very short and very tall persons, 96. The foot measure,
97.
SKIN of the sole, 98. On SHOES, 102.
THE HUMAN HAND.
HAND how distinguished from FOOT, 109. Construction of Upper limb, 110.
Small bones rarely dislocated, 112.
Movements at SHOULDER very free, 114; conducive to good development
of Chest, 125. Uses of COLLAR-BONE, 116. Injuries to Shoulder why so
frequent, 119. Shape of CHEST, 122; in Rhinoceros, 120; in Monkey, 123.
Movements at the ELBOW, 126. PRONATION and SUPINATION of the forearm
and hand, _ib._ No exactly corresponding movements in lower limb, 129.
MUSCLES by which they are effected, 130. Anatomical reason for the
direction in which we turn a screw or a gimlet, 132.
Structure and movements of the WRIST, 134. Movements of the FINGERS,
136. MUSCLES by which they are effected, 137. MOVEMENTS of the THUMB,
141; of the metacarpal bones upon the wrist, 143. Advantage gained by
the fingers and thumb all differing in length, 145. Middle finger the
centre about which the others move, 147. On holding the PEN, _ib._ The
direction in which the letters are slanted, 148. WRITING from left to
right, 149. Reason for the RING being placed upon the fourth finger,
150. The “funny-bone,” 153.
The MONKEY’S HAND, 154, 187.
The hand the organ of the WILL, 156; its relation to the MIND, 157; an
organ of EXPRESSION, 159. SHAKING HANDS, 162. Why do we shake hands?
162. Why do we KISS? 164.
Structure of the SKIN, 165. The Cuticle, 166; its uses, 167. The Rete
Mucosum, 166. Cause of the colour of the Skin, 167. The Cutis, 168.
Difference between a WART and a CORN, 170. How to cut Corns, 172.
NAILS; their formation and growth, 173. Claws in lower animals, 173,
175. Sensitiveness of the Skin beneath the nails, 177.
HAIRS; their formation, 178; colour, 179; uses, 180.
OIL-GLANDS; their uses, the odour of their secretion, 180.
SWEAT-GLANDS, 183; their structure, _ib._ The “Pores” of the Skin, 183.
The moisture of the palm, 184. Cold Sweat, _ib._
FEELING and TOUCH, 185. Structure of the three parts in which they are
most acute, _ib._ The “Pulps” of the fingers connected with peculiar
shape of the bones, 186; their sensitiveness to cold, 187. Distinction
between Common Feeling and the Sense of Touch, 188. Relation between
the two in the Tongue, the Eye and the Hand, 189. The tentacle of a
Polyp a rudimentary hand, 191. Acuteness of touch in man, 193; in BLIND
persons, _ib._
Relation of the hand to the EYE and the MOUTH, 195. The Elephant’s
Trunk, 197. CHEIROMANCY, 198. The LOCK-JAW fallacy, 200. Cause of the
superiority of the RIGHT HAND, 201. “This unworthy hand!” 205.
Explanation of Wood-cuts, 207.
THE HUMAN FOOT.
The Human Body is one of the most worthy objects of man’s study. It is
the noblest as well as the crowning work of creation. In it material
organization is carried to the greatest perfection. It surpasses,
therefore, all other physical objects in exquisiteness of construction
and in interest. How comes it, then, that most persons are so ignorant
respecting it? Men, well informed in other matters, are usually
altogether uninformed with regard to this. In every other branch of
science we find amateur students pursuing the subject with zeal and
success. Geology, Chemistry, Botany, Zoology, and even Comparative
Anatomy have each their votaries; but Human Anatomy attracts no one.
Why is this? Partly, I think, because opportunities for acquiring such
information as is suitable and interesting are not so many as they
ought to be.
It must be confessed, also, that we teachers of Anatomy are somewhat
to blame. We are too prone, in our Lectures and Examinations, to dwell
upon bare details, without enlivening those details with the many
bright features of interest with which they are naturally invested; and
we fail, therefore, to render it so attractive a science as it might
be. The example of those able and animated teachers, John and Charles
Bell, who laboured with some success to disperse the clouds that have
ever overhung the horizon of anatomy, has been too much forgotten; and
the flame which they kindled has almost died out under the chilling
apathy of their successors. Truly glad should I be to see a change in
this. I cannot but think that if the teachers of Anatomy took higher
and more philosophical views of their science there would be no lack
of interest on the part of the students. The interest so excited would
soon spread beyond the limits of the profession; and there would thus
be opened up to the public some of the products of that rich vein of
knowledge and of that abundant material for thought which lie buried in
the human frame.
I therefore willingly accede to your request for a Lecture upon some
part of the anatomy of the human body, relying upon the intrinsic
interest of the subject to make amends for my own deficiencies in
expounding it; and I select the HUMAN FOOT, because a few of the more
important points of its construction can be explained without much
difficulty, because it affords a good illustration of some of the
principles of animal mechanism, and because its form constitutes one of
the great characteristics whereby man is distinguished from the lower
animals. As an instrument of support and of locomotion it excels the
foot of any other animal. It evinces its excellence by enabling man to
stand upright in a way that no other animal can do; and so efficiently
does the foot accomplish this and perform the task of carrying the
body, that the hand is set at liberty to minister to the will. Thus is
the foot instrumental in giving us an advantage over other animals,
and in enabling us to provide the means of defence; and, thus, it aids
us to carry out those wondrous works which are second only to the
marvellous results of creative power.
We are accustomed to regard the hand as the great agent by which all
this is attained, and we are apt to forget how much it is indebted
to the foot. We do not reflect that, if the foot of man presented no
distinguishing peculiarity, the hand, like the corresponding part in
other animals, would be compelled to share with it the task of carrying
the body, and could, therefore, not be devoted to the various offices
which it is now free to perform. Little right has the hand to say to
the foot, “I have no need of thee.”
_The principle of “division of labour.”_
In this concentration of locomotive power in the foot we have an
illustration of what is called the “principle of division of labour,”
a principle with which all civilized communities are familiar, and
to which we are much indebted for the present advanced state of the
arts and sciences; but which we may be said to have borrowed from
the economy of nature. We find ever-increasing manifestations of it
as we ascend in the animal series, from the lower and more simple to
the higher and more complicated forms. Indeed, just as each step in
civilization is attended with a further development of this principle,
so is each division of the animal kingdom distinguished from those
below it by the more distinct assignation of particular functions to
particular organs, and by the consequent improvement of the mode in
which the functions are performed. While, in proportion as the several
organs acquire more distinct speciality in their work, so do they
become, more and more, dependent upon one another, and, more and more,
subjected to the control of central government, which is represented by
the brain.
For instance, some of the lower animals, as the fresh-water POLYP,
present nearly a uniform structure throughout their whole substance;
and every part of them consequently performs the same function. There
is not one organ for digestion, another for circulation, a third for
respiration, and so on; but all these functions are performed by the
same structure, and are performed, therefore, in a rude and imperfect
manner. Any portion of the creature possesses all the requisites for
its own nutrition, and is, so, independent of the remainder, and can
live alone. Hence, the polyp may be divided into a number of pieces,
each of which goes on living. Gradually, as we ascend from these lowly
beings to the higher classes of animals, we find organs and functions
more and more distinct from another; a Stomach is provided for the
work of digestion, a Heart for circulation, Lungs for respiration.
Each of these organs is essential to the existence of the others and
of every part of the body; and they are all maintained in harmonious
co-operation by the presiding influence of the nervous system.
Or, trace one of the _functions_ in illustration of the same principle.
Take the function of Locomotion, which has an especial relation to our
present subject. In the LEECH and the WORM the whole length of the body
is occupied in the work, one part as much as another; and still, it
is but a crawl. In the FISH the whole body is buoyed up by the water;
it is flattened from side to side, and is all, from the head to the
tail, concerned in the lateral stroke by which the animal is driven
along; the side fins, which are the representatives of limbs, doing
little beyond serving to guide and balance. In the other VERTEBRATES
the work of locomotion is so far concentrated as to be assigned, almost
entirely, to the limbs. All _four_ limbs are in most of them devoted
to it; while the bones and muscles of the trunk are only indirectly
concerned in it. In MAN, however, _two_ limbs only are assigned to this
important office. In him, therefore, the concentration of locomotive
power, in other words the principle of division of labour, is carried
out to the greatest extent--a disposition which affords one of the many
proofs that the construction of his body combines with the faculties of
his mind to place him at the head of the animal kingdom.
In making comparisons of different animals with one another, and in
speaking of the relative perfection of their several organs, we must
not forget that _every_ organ of every animal is perfect as regards the
purpose for which it was made. But some animals are said to occupy a
higher position than others, or to be superior to others, because their
mechanism is more complex, and they are, thereby, enabled to perform a
greater variety of functions. And, in the animal kingdom, in proportion
as each function rises into prominence, and becomes well and distinctly
performed, so is a special organ assigned to it, and that organ becomes
more and more highly elaborated.
You will not misunderstand me, then, when I say that concentration
of function and perfection of structure usually go together. And,
forasmuch as in the lower limbs of man there is a greater concentration
of locomotive function than in any other part of any other animal,
you will expect to find, in them, a greater perfection of locomotive
mechanism--that is to say, a more complete combination of strength with
variety, rapidity, and extent of movement--than is elsewhere to be met
with.
This consideration will ensure attention while I give a brief account
of the anatomy of man’s lower limb, more particularly of the foot.
_Structure of the Lower Limbs._
The weight of the trunk is transmitted to the knee (see fig. 4,
p. 15) by a single bone--the thigh-bone. This is the longest bone
in the body, measuring, on the average, nearly eighteen inches. Above,
it is jointed with the haunch-bone of the pelvis at the hip-joint.
From the knee two bones descend to the ankle. Of these one is much the
larger, and bears the chief of the weight. The other serves to give
attachment to muscles, and to strengthen the ankle-joint. It runs down
on the outer side of the ankle, forming there what is called the “outer
ankle;” and a process of the larger bone runs down, in like manner, on
the inner side, and forms the “inner ankle.” The front and inner side
of the larger bone are close under the skin. This part is called the
“_shin_,” being so named perhaps from the word “chine” or edge, because
the leg presents an edge along the front, to facilitate its cleaving
a way through the air, water, grass, or underwood. The shin itself is
not particularly tender; but the skin is a good deal exposed here,
and, as it lies so near the hard bone, it is easily injured; and, when
“broken,” it is often difficult to heal.
In some very tall persons, and particularly in those who are so tall
as to be called GIANTS, I have found the leg or shank bones, that is,
the bones between the knee and the ankle, very long, disproportionately
long to the rest of the skeleton. They are so in the skeleton of the
Irish Giant, O’Byrne, which is preserved in the Museum of the College
of Surgeons, in another Irish Giant in the Museum of Trinity College,
Dublin, and in some other specimens which I have had an opportunity
of measuring. In the name “Long Shanks” given to Edward I., the word
“shanks” probably included the thigh as well as the leg, just as we are
in the habit of applying the word “leg” to the whole of the lower limb.
_Bones of the Foot._
[Illustration: Fig. 1.]
There are 26 bones in the Foot. The hinder 7--called _tarsal_
bones--are short and thick; they form the hinder part of the instep. In
front of them lie 5 _metatarsal_ bones, one passing, forwards, from the
fore part of the tarsus to each toe. Behind, these are close together,
and are connected with the tarsus. As they run forwards they diverge a
little from one another; and their anterior ends rest upon the ground,
and form the “balls” of the toes. They constitute the fore part of
the instep. The remaining 14 bones are the toes. They are arranged in
rows, like soldiers in a phalanx, three deep, and are hence called
_phalanges_.
You observe that, although each of the other toes has 3 bones, the
great toe has only 2. In this respect, therefore, it is an imperfect,
or, rather, an incomplete member. The deficiency does not depend upon
a want of length in the great toe; for this is usually as long as the
second toe; in some persons it is a good deal longer; and it is always
distinctly longer than the outer two toes. The reason for there being
only two phalanges instead of three probably is because the great toe
is required to be stronger than any of the others; and an additional
bone would have tended to weaken it. I have, elsewhere[1], given
reasons for thinking that it is the middle phalanx which is absent in
the great toe.
[1] _Treatise on the Human Skeleton_, p. 395.
[Illustration: Fig. 2.
Seal’s Foot.]
[Illustration: Fig. 3.
Lizard’s Foot.]
It is a curious and interesting fact, affording a remarkable
illustration of the close adherence to a uniform plan which has been
observed in the construction of the various animals, that, in no
instance, does this toe contain more than two bones. Even in those
creatures, as the SEAL (fig. 2), in which it attains to greater
length than any of the other sprawling digits, it contains the same
number of bones as in man, its extraordinary length being attained by
an elongation of the two bones, not by the addition of a third. And in
those animals, as certain Lizards (fig. 3), where the number of
bones in the other toes is increased to 4 or even 5, the number in the
first, or inner, toe is still no more than two. The same rule applies
to the fore limb; the number of bones in the inner digit, which, in
man and monkeys, is called the “thumb,” is in no case more than two.
In some animals, as will be mentioned again, there is only one bone in
this digit, and in some the digit is wanting altogether; but in none
does it contain _more_ than _two_ bones.
This reminds me of a still more remarkable instance of adherence to
a particular number of bones. In the mammalian group of animals the
_neck_, with only one or two exceptions, contains _seven_ bones,
neither more nor less. Whether it be the long neck of the GIRAFFE, or
the short neck of the MOUSE, the BAT, or the PORPOISE, each consists,
like the neck in MAN, of seven bones. For what reason a particular
number should be thus rigidly observed, it is not easy to say.
Of the seven tarsal bones the uppermost (fig. 1) is called the
_astragalus_, from a supposed resemblance to a die. It is the middle
bone of the instep. Above, it is jointed with the leg-bones; behind,
it is connected with, and rests upon, the _heel-bone_, which is the
largest bone in the foot. The bone which lies immediately in front
of the astragalus, and supports it in this direction, is called the
_scaphoid_, or boat-like, bone. In front of it are three _wedge-bones_,
each of which is connected with one of the metatarsal bones of the
inner three toes. On the outer side of the wedge-bones, connected with
the metatarsals of the two small toes, and locked in between them and
the heel-bone, is the _cuboid_ bone.
I must confine my remarks chiefly to the _human_ foot. Still the
anatomy of man derives so much interest from being studied in connexion
with that of the lower animals, and is so much more instructive when
this is done, that I cannot forbear diverging, here and there, to
make a few comparisons. Let me, for a moment, draw your attention to
a similarity, in general construction, which exists between the lower
limbs of man, and the hinder limbs of other animals. And the comparison
may be extended to the fore limbs; for however diverse may be the
appearance and the mode of action of the limbs in different animals,
whether they be terminated by hands or by feet, whether they move upon
the ground or ply in air or water, whether they be attached to the
head, as are the front fins in many fishes, or, as is more common, be
situated at the fore and hinder parts of the trunk, the same plan is
traceable in all.
Great, indeed, is the variety of detail in nature. It is everywhere
observable. No two things, however near their resemblance, are
precisely alike. Yet, as I have before said, there is a remarkable
adherence to unity of plan. One star differs from another star in
glory, yet all appear fashioned in the same manner, and subject to
the same laws. There are almost infinite varieties in the vertebrate
kingdom. Each animal exhibits its own peculiarities; yet they are all
formed in the same manner, and are developed upon one fundamental
pattern, diverging from it in different ways according to the
requirements of each. Again, though the several parts of the same
animal differ from one another; yet in the skeleton the same bones
which exist in one part may, as a general rule, be traced in other
parts and in other animals. The bones which make up the pelvis in man
are repeated in his shoulder, and, even, in his skull; and they may be
recognised in the pelvis, in the shoulder, and in the skull, of all
other vertebrate animals, with few exceptions. They undergo, it is
true, great varieties in shape and size; but they can be shown to be
the same, or, in the language of anatomists, to be “homologous.” It is
highly interesting to the anatomist to trace the same bone through the
different parts of the same animal, and through the various animals
of the vertebrate series, and to observe the modifications which it
undergoes in order to adapt it to the multiform mechanism of the
several classes, to observe it sometimes dwindling, or even vanishing,
and then, it may be, reappearing under some new conditions.
[Illustration: Fig. 4.
Human Leg.]
[Illustration: Fig. 5.
Horse’s Leg.]
I must, however, resist the temptation to wander into this attractive
field. It will suffice to take an illustration by a comparison of the
bones of the human lower limb with those of the hind limb of the Horse.
This may be easily done by the aid of these drawings (figs. 4
and 5) in which the two limbs are placed side by side, and the
corresponding bones are marked with the same letters. Notwithstanding
the many points of difference the same plan will be recognised in each.
There is in each the thigh(C), the leg(E), and the foot, with the
tarsal and metatarsal(G) bones, and the phalanges(H, I, K). But in the
HORSE two of the digits (the marginal ones, that is, the great toe and
the little toe) are wanting, two are rudimentary, and the remaining
one, which corresponds with the middle toe of man, in length, size,
and strength, more than makes amends for the deficiency of the others.
The lowermost bone, or terminal phalanx, of this huge toe, called the
_coffin-bone_(K), is encased in the hoof, which corresponds with the
human nail, and is the only part of the foot that rests upon the ground.
In MAN the whole weight of the body has to be borne upon _two_ feet;
often it is balanced upon _one_. The foot is, consequently, spread out;
and all the bones, from the heel to the tips of the toes, are made to
form the basis of support upon the ground. The HORSE, on the contrary,
having no hands, but _four_ feet, does not require so great breadth
in each foot; and the opportunity is taken to narrow the foot, and to
lengthen it so as to give fleetness. The end is attained by suppressing
some of the toes, by elongating one far beyond the others, and enduing
it with such strength as to enable it to carry the requisite weight
upon the tip of the last phalanx. The heel(F) is raised high above the
ground and becomes the “hock.” To speak of a horse _kicking with his
heels_ is, therefore, about as correct as to say, that he _breaks his
knees_. His knee, as you perceive by the position of the “knee-cap”(D),
is high up in the hind limb, near his body, quite out of harm’s way in
a fall. The fact is, that he kicks with his _toes_; and, when he falls,
he cuts the skin over the part in his _fore_ limbs, which corresponds
with the back of our _wrists_.
In the upper segment, or thigh, the difference between the two limbs
is seen to be, to a certain extent, the reverse of what it is below.
That is to say, whereas, in the HORSE, the _toe_ is elongated and
thickened, so as greatly to exceed the corresponding part of the human
limb; in MAN the _thigh-bone_ is elongated, so as to be double the
length of that of the horse; the thigh-bone in man is also placed more
vertically, nearly in the plane of gravity of the trunk. The horse’s
thigh-bone slants forwards and outwards, which gives the muscles great
power by causing them to run more at right angles between their points
of attachment; and this arrangement increases the strength of the
animal in drawing weights, and facilitates springing. A man cannot
spring without first bending the limbs a little; whereas a horse, or a
goat, can spring, at once, from the position in which it is standing.
To revert to the anatomy of the Human Foot.
_The Arch of the Foot._
The seven tarsal and the five metatarsal bones--that is, the twelve
bones of the instep--are arranged and jointed together so as to form
an arch from the point of the heel to the balls of the toes. This is
called the “plantar arch,” from the Latin word _planta_, the sole of
the foot. The _astragalus_ forms the summit, or key-bone, of the arch.
It receives the weight from the leg, and transmits it, through the
hinder pillar of the arch, to the heel, and, through the front pillar
of the arch, to the balls of the toes.
[Illustration: Fig. 6.]
The drawing represents a section, from behind forwards, of the lower
end of the leg-bone, and of the bones lying along the inner side of the
plantar arch. Behind it extends through the heel-bone, and in front
through the great toe. It exhibits the arrangement of the fibres and
plates in the interior of the bones, and shows that the greater number
of them, in each bone, follow the direction of the two pillars of the
arch; that is to say, they descend from the summit of the arch where
it supports the leg-bone, backwards and downwards, to the heel, and,
forwards and downwards, to the balls of the toes. Their arrangement
is, therefore, such as to give resisting strength to the bones in the
directions in which it is most required.
You may think that the arch of the foot would have been a much simpler
structure, as well as stronger, if it had been composed of one bone
instead of several. But it must be remembered that it would, then, have
been liable to be cracked and broken by the sudden and violent manner
in which, during running and jumping, the weight of the body is thrown
upon it. Moreover, the several bones, where they touch one another,
are covered with a tolerably thick layer of highly elastic gristle or
cartilage (represented by the clear line left in the drawing along
the contiguous edges of the bones); and this provision, together with
the slight movements which take place between these bones, gives an
elasticity to the foot and to the step, and serves to break the jars
and shocks which are caused by the sudden contact of the foot with the
ground.
This last is a very important point; and we find numerous contrivances
in different parts of the body to protect the brain and other
delicate organs from jars. So efficient are these contrivances, and
so exact is the adaptation of the mechanism of the limbs and the
trunk to the texture of the internal organs, that, while these are
in a healthy state, we are able to run, to jump, and to leap from a
considerable height, without inconvenience. But, if the organs be
inflamed, or if the nervous system be over sensitive, as in common
headache, the provisions, which are calculated for the normal state,
are insufficient; ordinary movements are then painful, and to jump is
intolerable.
The muscles play a very essential part in this work. _First_, they
place the limbs in the most favourable position. Thus, when we alight
upon the ground, from a height, we always contrive to do so with the
knees and hips a little bent, so that the limbs readily yield at the
joints, and act as springs to break the jar. Elderly persons commonly
keep the limbs bent, even when walking quietly along. They do this
because they need all the benefit which position will afford to make
amends for the loss of elasticity consequent on the thinning and drying
of the cartilages, and other changes that take place in the body with
advancing years. _Secondly_, the muscles brace the limbs and joints in
the position in which they have placed them. We experience the effect
of the want of this salutary influence when we kick against an unseen
object, or fall suddenly, or receive any blow or shock for which we are
unprepared. How disagreeable, to say the least, it is to make the step
for an additional stair when we have arrived at the top of a staircase,
or, still worse, to meet with an unseen stair when we think that we
have got to the bottom.
You perceive from the drawing (fig. 6) that there is a great
difference between the two pillars of the plantar arch. The hinder
pillar is comparatively short, and narrow, and descends suddenly,
almost in a vertical direction, from the ankle, to the ground; and it
is composed of only one bone--the heel-bone--which is jointed directly
with the astragalus: whereas the fore pillar is longer and broader,
is composed of several bones jointed together, and slopes much more
gradually to the ground. There is, therefore, far less elasticity in
the hinder part of the foot than in the fore part. Hence, when we
descend from a height upon the ground, we always alight upon the balls
of the toes, and thus gain the advantage which the several bones and
joints afford in breaking the shock. If, after going up stairs this
evening, you take the trouble to come down again, you will find that
you alight upon each stair on the balls of the toes and experience no
inconvenience, however quickly the descent is made. But, if you change
the mode of proceeding, and descend upon the heels, the feeling will
be by no means agreeable; and the various organs of the body, being
disturbed from their accustomed repose, will raise such remonstrances
against your infringement upon nature’s ways, that you will scarcely
be able to continue the experiment. Proportionately more distressing
is the sensation caused by jumping from a chair upon the heels.
Indeed, this is not done altogether without risk; and the trial of it
is scarcely to be recommended to persons who have attained to that
sober period of life at which we are willing to concede that, in some
things, nature is wiser than ourselves. Only a short time since I
saw a gentleman, who, in jumping down some steps into a back yard,
accidentally came upon his heels, and jarred one hip so severely that
he was confined to his sofa for several days in consequence.
But, you may say, “in walking we do place the heel upon the ground
first and experience no inconvenience.” True, because the force with
which the foot descends in walking is very slight; and the weight is
directed upon the heel, obliquely, in such a manner as to bring the
toes very quickly to the ground, and really to throw nearly the whole
force in that direction. Moreover, you may observe that when we walk,
the weight of the body is partly sustained by the fore part of the
one foot till the whole of the other foot is on the ground. I will,
however, revert to the disposition of the feet in walking and running
presently.
The arch of the foot has to bear great weight and at great
disadvantage; and there is very little in the _shape_ of the bones to
maintain its integrity. Indeed, they all fall asunder when the other
structures are removed, the key-bone dropping through of its own
weight. And the same thing may be remarked throughout the skeleton.
Wherever two or more bones move upon one another, their surfaces are
so constructed that they do not hold together without some assistance
from the soft parts. There are joints in the body which we call
“hinge-joints,” and others which we call “ball-and-socket joints;” but
in none of them is there such a holding and locking of one part in the
other as you have in the hinge and the ball-and-socket of the mechanic.
In every case the bones are held together, not by their own shape, but
by ligaments and muscles. Consequently, any one of the bones may be
dislocated from those next it without breakage; and when the muscles
and ligaments are cut through, or have been destroyed by maceration,
all the bones, between which any movement was possible during life,
separate from one another.
Not only is this so, but in no instance are the movements of joints
_limited_ simply by the shape of the bones--that is to say, they are
never brought to a stop by a part of one bone coming into contact
with the edge of another. Such a contact would have caused a _sudden_
check; and this would have been attended with more or less jar and with
some danger of chipping and breaking the articular edges. The range
of movement of a joint is always regulated by the ligaments or the
muscles, not, directly, by the bones; and the restraint thus imposed
upon the movements is brought to bear, not suddenly, but _gradually_;
somewhat like the effect of the “break” upon a railway-train; while the
cartilages between the bones may be compared with the “buffers” between
the carriages.
It is chiefly by means of strong LIGAMENTS, or sinewy bands, passing
from bone to bone, that the shape of the plantar arch is maintained and
the movements of the bones upon one another are regulated and limited.
These ligaments are numerous; but I will mention only two.
[Illustration: Fig. 7.]
One, the _Plantar Ligament_ (A, fig. 7), of great strength,
passes from the under surface of the heel-bone, near its extremity,
forwards, to the ends of the metatarsal bones; in other words, it
extends between the lowest points of the two pillars of the arch,
girding, or holding, them in their places, and preventing their being
thrust asunder when pressure is made upon the key-bone (D); just as
the “tie-beam” of a roof resists the tendency to outward yielding of
the sides when weight is laid upon the summit. The ligament, however,
has an advantage which no tie-beam can ever possess; inasmuch as a
quantity of muscular fibres are attached along the hinder part of its
upper surface. These instantly respond to any demand that is made
upon them, being thrown into contraction directly the foot touches
the ground; and the force of their contraction is proportionate to
the degree of pressure which is made upon the foot. Thus they add a
living, self-acting, self-regulating power to the passive resistance
of the ligament. In addition to its office of binding the bones in
their places, the ligament serves the further purpose of protecting
from pressure the tender structures--the blood-vessels, nerves and
muscles--that lie above it, in the hollow of the foot, under the
shelter of the plantar arch.
Another very strong ligament (B in the wood-cut) passes from the under
and fore part of the heel-bone (F) to the under part of the scaphoid
bone (E). It underlies and supports the round head of the astragalus,
and has to bear a great deal of the weight which is transmitted to that
bone from the leg. It does not derive the same assistance from a close
connexion with muscular fibres as the ligament just described; but it
possesses a quality, which that and most other ligaments do not have,
viz. elasticity. This is very important, for it allows the head of the
key-bone (D) to descend a little, when pressure is made upon it, and
forces it up again when the pressure is removed, and so gives very
material assistance to the other provisions for preventing jars and for
giving ease and elasticity to the step.
A glance at the drawing will show you that here is a weak point in the
foot. The head of the key-bone receives great weight from the leg,
but is comparatively unsupported; and there is a considerable strain
upon this part when the heel is being raised in walking. Moreover,
a good deal of movement takes place between the key-bone (D) and
the scaphoid bone (E), more than between any other two bones of the
instep; and freedom in the range of movement is generally attended
with some sacrifice of strength. The strong elastic ligament comes in
therefore with peculiar advantage at this point; and it is underlaid,
and additional support is afforded exactly when it is most required, by
the tendon (b in fig. 12) of a strong muscle, the especial office
of which is to assist in raising the heel and bending the instep, and
which runs, from the back of the leg, behind the inner ankle, to the
scaphoid bone.
_Weak Ankle and Flat-foot._
In spite, however, of the thick elastic ligament and the strong
tendon just mentioned, the joint between the astragalus or key-bone and
the scaphoid bone still remains a weak point. The head of the key-bone,
from being insufficiently supported or from being overweighted, is very
apt to descend a little below its proper level; the consequence of
which is that the plantar arch is lowered and the foot is flattened;
and the more the foot is flattened the weaker it necessarily is,
because the position of the bones then becomes less and less favourable
for bearing weight, and an increasing strain is thus incurred by the
ligaments and muscles. Hence the foot and ankle feel weak; and the
weakness is especially felt when the person endeavours to raise the
heel, so as to mount upon the balls of the toes, in walking. For the
performance of that movement with ease and steadiness a well-formed
plantar arch is essential; and the person, whose feet are defective
in the manner we are considering, can never walk with a bold, firm
step. The movement in him may be better described as a shuffling from
one foot on to the other, than as a walk. To this I will recur again
when I come to speak more of walking. The defect, when slight in
degree, is commonly called “weak-ankle;” when more decided it is called
“flat-foot,” because the sole is then nearly, or quite, flat. The head
of the key-bone, under such circumstances, may even bulge downwards and
inwards, and form a prominence on the inner side of the sole, so as
to give more or less _convexity_ to the line on the inner side of the
foot, which should be _concave_.
[Illustration: Fig. 8. Flat-foot.]
The representation of “flat-foot” here shown was drawn from the foot of
a labouring man in this county. He said he believed the deformity was
due to his having worn thick tight shoes when he was a growing boy. He
is most likely right in his opinion; for tight or ill-fitting shoes,
cramping the feet and preventing the proper growth of the bones and the
free play of the muscles, are a common cause of this evil. This is so
especially among the agricultural class, whose feet are, from an early
period, enclosed in stiff unyielding leather cases that are enough to
mar nature’s best efforts to construct a plantar arch.
The same drawing shows that flat-foot is not the only deformity
for which “high-lows” are answerable. Besides the almost total want
of calf, which is due to the wearer being obliged to hobble along,
whole-footed, with short feeble steps, it will be seen that the great
toe has not been allowed to assume its natural straight line, but has
been squeezed athwart the other toes, so as to be almost at a right
angle with the foot. No room at all is thus given for the second toe;
it has been driven quite out of the field, and has been obliged to hide
itself by bending down under the other toes. This is no uncommon state
of things. Frequently it is attended with the formation of a painful
bunion upon the prominent inner side of the ball of the great toe;
and, in addition, there is sometimes a corn upon the first joint of
the second toe, which is a source of so much inconvenience that I have
known many sufferers glad to get relief by parting with the toe.
I wish I could hope that the days of high-lows are numbered, and could
believe that in the next generation they will be ranged with the things
of the past, and that our children may know these enemies to the form
of the rustic foot, only as objects to be gazed upon with feelings of
astonishment and pity, just as we regard the perukes and the stays of
our ancestors. There are, however, some practical difficulties in the
way of the fulfilment of this charitable wish.
There are two periods of life at which FLAT-FOOT is most likely to be
engendered. _First_, in infancy, if the child be put upon its feet too
early, before the bones and ligaments are strong enough to bear the
weight of the body. Therefore mothers should not indulge their anxiety
to see their infants walk very early; the pride attendant on premature
success is liable to be followed by regret at finding that the children
never walk well. Parents and nurses should be content to let the
children crawl and roll about upon the floor, and should not encourage
them to stand upright, especially if they be rather heavy or weak
children. Children are quite sure to acquire the faculty of walking as
soon as they are well fit to exercise it.
The _second_ period is at about fourteen. The body attains a
considerable increase of weight at this time, in consequence of the
quick growth that takes place. We often remark that lads and girls
of this age shoot up apace; and their greater weight is not always
attended with a proportionate acquisition of strength. They are apt to
be rather weak and ungainly in their movements; and the weakness often
shows itself in the foot, by a yielding of the plantar arch. Moreover,
many boys and girls are, at this age, turned out into the world to
earn a livelihood, and are obliged to be a good deal upon their feet,
and perhaps, in addition, have to carry weights. Thus errand-boys,
butchers’ and bakers’ boys, and young nursery-maids, are frequent
sufferers in this way. The constrained positions in dancing, also,
if enforced too much, or continued too long, so as to tire the feet,
sometimes lead to the same result. On the other hand, moderate exercise
of this kind is calculated to strengthen the foot and also the whole
frame, and contributes much to improve the carriage.
This is not the place to enter into particulars of _treatment_. I
will, therefore, merely remark that the common notion of supporting
and strengthening the ankles by tight-laced boots is altogether a
mistake, and must be ranked among the most influential of the causes
which combine to spoil so many feet. It has its parallel in the idea
of strengthening the waist by stays. The notion is, in both instances,
fortified by the fact that those persons who have been accustomed to
the pressure, either upon the ankle or the waist, feel a want of it
when it is removed, and are uncomfortable without it. They forget, or
are unconscious, that the feeling of the want has been engendered by
the appliance, and that had they never resorted to the latter they
would never have experienced the former; just as dram-drinking induces
a recurrence to the stimulus by causing a sense of sinking when it is
discontinued; and, for the same reason, the opium-eater can hardly
exist without his drug.
_The Movements of the Foot._
We come now to the MOVEMENTS of the foot upon the leg; and rarely do we
contemplate anything more calculated to excite our admiration. Consider
their variety, the rapidity with which they take place, in order to
effect the requisite succession of positions in walking and running,
and to adapt the sole to the inequalities of the surface on which we
tread; and remember the great weight which has to be sustained while
these movements are going on: yet, how seldom is there a failure.
This combination of variety of movement with security is effected by
the employment of _three_ joints, each of which plays in a direction
different from the others, while all act harmoniously together.
_One_ of the three joints--strictly called the “ankle-joint”--is
between the leg-bones and the foot-bones, that is, between the tibia
and fibula, above, and the astragalus beneath. By means of it the foot
may be bent or straightened upon the leg; in other words, the toes may
be raised or depressed. In this movement the heel participates, being
depressed when the toes are raised, and _vice versâ_. A _second_ joint
is between the astragalus and the heel-bone. It permits the foot to
be rolled inwards or outwards upon an antero-posterior axis; so that
the sole may be turned inwards, with its inner edge upwards, or may be
turned down so as to be placed flat upon the ground. A _third_ joint is
between the first and second row of tarsal bones--that is, between the
astragalus and the heel bone, behind, and the scaphoid and cuboid bones
in front. It permits the degree of flexure of the tarsal or plantar
arch to be increased or diminished.
Had the several movements which are requisite for easy walking all
taken place in one joint, that joint must necessarily have been very
insecure; indeed, it must have been a “ball-and-socket” joint, and we
should have been poised upon our feet in the state of what is called
“unstable equilibrium”--a state quite incompatible with security or
strength, and which would have rendered the assistance of the upper
limbs essential to either standing or walking.
An instance of a similar kind of mechanism to this of the joints
between the foot and the leg is presented by the mode in which the
head is secured upon the back-bone. We can nod the head upwards and
downwards; we can turn it to either side in so free a manner that we
are able to command with our eyes the whole circle in which we sit
simply by the movements of the head; and we can incline the head to the
right or to the left. Any of these movements may be made very quickly;
and there is a separate joint or joints for each of them. Thus, the
_nodding_ movement takes place between the head and the first vertebra
or uppermost bone of the spine; the _turning_ of the head from side
to side takes place between the first and second vertebræ, the head
with the first vertebra rotating upon a pivot projected upwards from
the second vertebra; and the _inclination_ of the head from side to
side takes place by movements of the second vertebra upon the third,
of the third upon the fourth, and so on. The result is that, although
the movements are thus varied, they are free as well as rapid. Yet the
head is so well poised and so strongly fixed that the neck is able to
bear it all day long without fatigue; and, as though the weight of the
head, which is by no means inconsiderable, were not enough for the
neck, we are in the habit of selecting this as the part upon which to
carry burdens. One never feels so strongly impressed with the carrying
capabilities of the neck and the ankle, as when following men and women
in mountain districts toiling up and down the hills under great bundles
of hay, baskets full of bitter beer, and various things intended to
minister to the comfort and luxury of travellers and the inhabitants at
the top. So effectual, indeed, are the provisions for security that,
notwithstanding the freedom and variety of their movements, the joints
of the foot with the leg, and of the head with the spine, are, in
proportion to their size, the strongest in the body.
I have stated the movements that take place in the three joints of
the foot with the leg in a simple manner, for the sake of avoiding
confusion. In reality, however, they are not so simple, but very
difficult to analyse and make out correctly. The difficulty is due,
partly, to the close proximity of the joints to one another, which
renders it no easy matter to distinguish the movements of one from
those of the others, and, partly, to the fact that the movements in
each joint are a little oblique.