OK, I don't want to put off knife grips any longer…
I'm going to discuss blade-forward grip (blade extending from
thumb side of grasp) in terms of three distinct alternatives
(although there is a continuous gradation between them and a
number of variants I don't discuss). I'm also going to ignore
double-edged blades and all versions of reverse grip (knife
extending from pinkie side of grasp).
For expository purposes we'll assume a knife that has a
straight handle in line with the point, and a handle cross-
section that makes it meaningful to speak of right and left
sides of the handle and also of top and bottom (i.e., not too
round).
The main point I'm pushing is the tradeoff between security
and dexterity/finesse with different grips and at least some
consideration to the option of 'finger play'.
To begin with, place the back of your hand flat on the table
aligned with your forearm (no radial or ulnar deviation).
First case: Place the side of the handle of the knife across
your palm at right angles to the line of your forearm. Place
it 'high' in the palm of your hand, only 2 inches or so from
your wrist, just touching the edge of the meaty base of your
thumb. Now curl your fingers to grasp the handle and curl
your thumb around as well, with the tip/ball of your thumb
touching the 'intermediate phalange' of your forefinger. [See
footnote 1 re terminology - I hope this pedantry aids precise
understanding]
Take your hand from the table and let's see what we can
observe about this 'hammer' grip.
Well, it's a *very secure* grip with great finger and thumb
wrap of the handle, and we can grasp the handle really tightly
- it would be hard to dislodge the knife from our grasp.
On the downside, however, note the following:
1) Even with maximum ulnar deviation it's impossible to
bring the point anywhere close to in-line with the forearm -
it's going to be impossible the thrust well with this grip.
2) Our wrist mobility is considerably restricted. See what
size circle you can trace with the tip using only your wrist -
it's not very large.
3) A snap-cut isn't very snappy.
4) The 'tightness' of our grasp 'radiates' into our whole
forearm and this will tend to make our actions slower and more
clumsy: our actions are going to be very 'muscled'.
5) There is no 'natural' sense of the orientation of either
the point or the edge - it's very approximate. This will
make good cutting difficult (recall my stressing the
importance of the alignment of the edge with the direction of
a cut)
Second Case: Back of hand on table as before. This time
place the side of the handle across the middle of the first
(proximal) phalange of your forefinger to the crease/joint at
the last (distal) phalange of your pinkie. Now, still keeping
your fingers flat, bring your thumb over and, using the *side*
of your thumb knuckle and a bit of its distal phalange, press
the handle against your forefinger's proximal phalange in a
sort of 'sideways pinching' grip. Grip the handle using only
your unbent thumb and forefinger.
Now lift your hand from the table. Unless you've done this
exercise before this grip is going to feel very weird and
unnatural. The most obvious point right now is that it's not
very secure. But keep exploring...
Now, keeping your thumb and forefinger sideways pinch grip,
and with forearm roughly horizontal, turn your hand so that
the blade points upwards and forwards.
Try curling/bending your last three fingers to bring the rest
of the handle into your palm. (Your forefinger can stay
straight or bend a little but retain the sideways pinch as a
pivot.)
Clench and unclench the last three fingers back and forth -
the knife (especially if handle-heavy) will tilt up and then
go nearly horizontal as your grip tightens. When the last
three fingers are bent and the knife is pushed into your palm
your grip will feel a lot more secure than when the knife has
only the forefinger/thumb pinch. But still *way* less secure
than the hammer grip!
Ok, close your last three fingers (you can't really 'grip'
with them, only press the handle into your palm - you sure
aren't going to overtighten your muscles with this grip!). As
you get (slightly) more comfortable with this grip, experiment
with it. For instance, see how big a tip circle you can make
with wrist action - really big! Can you bring the point into
line for a thrust? You bet. In fact it's easy to 'write your
name in the air' with the tip - you have a *lot* of dexterity
and control!
Now try the ultimate purpose of this exercise - finger play!
Try doing a miniature snap-cut just by opening and closing
those last three fingers. Again and again! Then try doing
snap cuts with *both* finger and wrist action coordinating and
unifying them.
Ok, great dexterity, lousy security. But you did get
introduced to finger play, a subject about which many knifers
know nothing!
Third Case: I'm hoping to convince you that this is the
Goldilocks case - not too this, not too that, but just right!
The Goldilocks case is saber grip and it's a close relative of
the last insecure one, but the small differences go a long way
to making it a much better grip. I'm going to cheat - but
only just a little - in describing it to show it off to best
advantage.
Hand flat on table. Place the handle across the middle
phalange of the forefinger to the 'fleshy pad' on the palm
adjacent to the proximal phalange of the pinkie. Place your
straight (or very slightly bent) thumb against the back of the
blade as you curl all four fingers around the handle. Lift
hand from table.
The 'pivot' is formed by the fleshy pad of your thumb pressing
on the back of the handle (or even on the back of the blade
itself) with the bottom edge of the handle across the middle
phalange of your forefinger (or even a bit further out, on the
crease/joint between the intermediate and distal phalanges)
This time even just the thumb/forefinger grip gives pretty
good security since the thumb can press very hard against the
curled forefinger. And, when closed, the last three fingers
can also clench hard. Not quite 'hammer grip' security but
pretty damned good.
And by clenching and unclenching the last three fingers you
can still use finger play - if you choose. Or not.
Point in line, size of tip circle, no muscle tension radiating
up the arm, and other criteria are all pretty good, especially
if the last three fingers are relaxed a bit. IOW the
security/dexterity tradeoffs are pretty good and pretty
controllable.
But I've saved the best for last. (Well, maybe not the best,
but definitely an important point.) Thumb in saber grip gives
an excellent sense of both point and edge orientation. For
instance, you can point with your thumb almost as well as with
your forefinger. The following 'homunculus diagram' gives
some idea of what a disproportionately large amount of the
sensory/motor cortex is devoted to the face and hand, and more
particularly, our item of interest, the thumb.
http://thebrain.mcgill.ca/flash/i/i_06/i_06_cr/i_06_cr_mou/i_
06_cr_mou_1b.jpg
*****
OK, you've gotten the rap. Now experiment and fine-tune to
find the grip that's exactly right for you. Just remember the
examples and principles covered such as gripping with 'more
fingers' and 'less palm'.
Regards,
1) Terminology: bones of the hand.
http://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Schem
e_human_hand_bones-en.svg/190px-Scheme_human_hand_bones-
en.svg.png