HAND:
Probably the most complex part of the muscle and skeletal
linkages are in the hands (and feet). Like any body region, the
hands are made of frame members, connecting ligatures, muscles and
tendons of various layers, skin, and certain other systemic components and other regional features (like nails).
The limbs; arms and legs; are processed or fabricated from
distal to proximal; the phalanges to the torso. This is because
tendons to the phalanges are generally pulled by concentric (or
even eccentric) contractions of the muscles closer to the body
along the limb. There are some interosseus muscles that abduct and
adduct the fingers (laterally ) within the hand itself. Also, if
there is a method developed to put a nice, seamless, strong skin on
in sections, the hands and feet could be finished and sealed while
the remainder of the body is in work receiving your full attention.
Be careful with the pot life of any tendon and actuator
materials. Hand surgery is more delicate than brain surgery so
repairs will be risky and difficult. There will be a mixture of
tendons, aponeurosis, cartilages, and sheaths in the hand.
Designing/Engineering Notes:
There are few applicable engineering notes to the hand, yet,
as of . Some applicable notes will likely be in the
"finger," "finger nails," "Finger; ring size," and "fingerprints"
topics. However, from the trivia section: The average hand is as
wide as the third finger is long.
Frame Elements:
The frame element classifications of the hands are the
.carpals;
consisting of the first row from the thumb:
# Scaphoid,
# Semilunar,
# Cuneiform, and
# Pisiform (the only one of this group that does not present
6 surfaces) articulating with the Radius and Ulna and the
second row of the
# Trapezium,
# Trapezoid,
# Os magnum, and the
# Unciform articulating with those of the first row and with
.the metacarpals;
[Gray] numbers from 1 at the thumb to 5 for the little
finger so the third metacarpal is of the middle finger ...
"the one that flies the bird,"
and
.
the phalanges (two per thumb and three per finger totalling 14
bones per hand or 28 phalanges of the hands per person
which is the same number as the feet) are numbered by
[Gray] for their respective row of the fingers where the
first row articulates with the respective metacarpal, the
second row with the first row, and then the third row;
the finger tips; with the respective second row phalanx.
It may be possible to size and shape the index and ring finger
components alike. Mine look very much alike. This will reduce the
number of drawings and different parts to manage. It also may be
possible to get by with three different part numbers for fingertip
bones for both hands as [Gray]'s drawings seem symmetrical.
The bones of the hands have very complex synovia and ligature
attachments with regard to the innermost layer. TEFC is the material of choice for the ligatures.
Articulations:
Curiously, the joints of the hand does not have any deepest
internal ligatures for its movements. However, the bones of the
hands have very complex synovia and ligature attachments from the
Radio-ulnar articulations to the Carpo-metacarpal articulations.
Admittedly, more engineering work is needed within this area to
even suggest a procedure to apply the ligatures. Gray, pages 259
through page 266 , and many other references, will need extensive
study.
However, any articulation involving the phalanges of the
fingers seems simple by comparison to the remainder of the hand.
The anterior ligaments have a groove formed in them for the flexor
tendons made from TEFC for this innermost layer. Each phalangeal
joint has two lateral ligaments as described in Gray, pages 267-268.
The hands have other ligatures that were not a part of articulating the skeleton. These ligatures and fascia allow tendons to
move between the tissues without friction. Deterioration in one of
these primary tissues is responsible for "Carpal tunnel syndrome"
in humans. (See [Gray, p. 401, Fig. 239] for a section view at the
carpus. See also [Gray, Fig. 242] for muscles of the thumb.)
Innermost Layer of Muscles and Other Tissues:
These comprise this deepest layer's muscles. The applicable
adductors for this innermost layer of adductors of the hands are:
. Dorsal interossei (4)
and
. Palmar interossei (3).
These are numbered increasing from the thumb; e.g. the First Dorsal
interossei is between the thumb and index finger.
Intermediate Layer of Muscles and Other Tissues:
The applicable actuators for this intermediary layer of the
hands are subdivided into the "deeper of the middle layer," "middle
of the middle layer." and "outermost of the middle layer." And for
the deeper of the middle layer:
. Lumbricales (4)
and
. Opponens pollicis.
Middle of the middle layer:
. Each of the tendon of the extensor muscles [Alexander, p. 22]
is attached at the inner half of the outer phalanx of the four
fingers at one end. The other end of each tendon may merge
and split towards extensor muscles.
. Flexor brevis pollicis,
. Adductor obliquus pollicis,
. Adductor transversus pollicis,
. Flexor brevis minimi digiti,
and
. Each of the tendon of the extensor muscles [Alexander, p. 22].
Outermost of the middle layer:
. This paragraph is a placeholder. There is no respective
muscles in this layer. Any muscles and fascia superficial to
those of this section are in the outermost layer chapter that
follows this one. (Future changes or revisions may move some
of the inner-middle or middle-middle layer muscles about and
relocate some here.)
Internal Components:
The respective internal components of the hand to be installed
are the:
. Fingertip tactile sensors
and
. temperature sensors.
However, this does not rule out the possibility of locating certain
sub-processors within the bones or between actuators for design and
construction reasons even though they must be small for this area.
Outermost Layer of Muscles and Other Tissues:
The applicable human and android muscles for this last, outermost layer of the hands are:
. Abductor minimi digiti,
. Abductor pollicis,
and the
. Palmaris brevis.
Final Layers and Artifacts:
Certain subcutaneous fat is used to protect the skin from
articulation abrading. A little more in femdroids with their substantially smaller hands adds to the feminine softness desired.
The fingernails, ten of them, have five different sizes
bilaterally. Sizes include the size of the billet, shape, and
thickness. If the index and ring fingers could use the same size,
then only four different nail sizes are needed per individual
android.
Finger nails can be glued-in "Lee nails" or from some similar
drug-store or cosmetic counter product. They are anchored at the
joint end and edges between the dermis and epidermis layers. Mask
the nails, like the cosmetic pattern, for the epidermis
application.
Inspection Criteria:
The hands should move in the same way and with the same range
of movement as yours. Assuming that you are a natural human.
Trivia:
"If you're [sic] typical, ..., your wedding ring size is the
same as your hat size." [Boyd, 2 Dec. 1992, pg. 22.]
"Your hand is of typical width if its about as wide as your
third finger is long." [Boyd, 19 June `94].
INDEX: See "Does Your PC.Or How You Use It.Cause Health
Problems," [PCM, Nov. 26, 1991, pg. 491.] and see also;
[SN, v.147 (`95a); 15] for more information.