The new BeBionic3 hand is out!
The previously documented grip patterns of the BeBionic2 hand are still there with this product. It looks fabulous. And it is more stable and robust than ever.
There is a video to watch. Further down, I will compare BeBionic 3 hand grips to my own grips, and evaluate the relevance from my view as a well coordinated user of a massively tweaked body powered arm, and I have enough muscle power, to also type up all this.
Here is a list of the grips, their intended use, my body powered adaptation of these grips, and how I interprete their use in the light of what wearing prosthetic arms is really about - avoiding overuse (see category of articles related to that, and some specific requirements for a prosthesis).
|Grip name (BeBionic3 grip, other designation)||Description||How I perform it||How many times a day I use this (estimated)||Importance rating 1-10|
|Tripod||Grip items between thumb, index and middle finger to grip pens, car keys and coins.||I use the pinch grip of the Becker hand or hook.||Not often.||1|
|Pinch||Index finger and thumb oppose for the pinch grip. It is used to hold and pick up car keys, coins, jar lids and pens.||I use a mix of pinch and lateral grip using the hook or Becker hand all the time. It covers many aspects of life. I particularly need it to rip open packages, hold cables, connectors, to sew, and so on. Overuse risk comes from not being able to reliably hang heavy wet laundry, for example, as well as highly repetitive similar activities done when preparing food, for example. The pinch (or lateral pinch) grip both are relevant for that. But that only helps in conjunction with a really light socket, with a perfectly reliable open and close control, and with fast action.||50-100||7|
|Power||All four fingers as well as the thumb close in for an adaptive grip to any object.||The Becker hand adaptively grips all of my required items. Alternatively, I use a prosthetic hook that offers a cleverly shaped grip option that is not adaptive. Both are really useful for power grip. Overuse risk comes from not being able to scrub, or, to vacuum, or, hold on to heavy power tools or other heavy items. The power grip certainly - along with a good pinch grip - makes for most of the overuse reduction I get from my prosthetic arm.||100-300||7|
|Active Index||Trigger type actions such as using a spray bottle require a grasp of the bottle, with an extended index finger, then there will be flexion of the index finger.||I cannot do that, but then, I do not spray stuff often either. My shaving foam and deodorant contain buttons one has to push downward, so the active index would be useless. Most of my detergents are not spray bottles but bottles with small openings that I pour the content out of.||1-2||1|
|Key||This is a lateral pinch grip with the thumb pressing against the base of the index finger. It is used to carrying papers, holding a spoon or thin flat objects such as CDs, credit cards or turning a key in the lock.||A hook or Becker hand naturally manages to hold and stabilize papers, other flat objects and so on. It is a frequently occurring grip for me.||5-80||3|
|Finger point||The extended and stiff index finger can be used to type or push buttons.||This is how I type. I either use a hook or I squeeze a pen into the Becker hand. Both work very well. Relaxed posture and real mechanical stability are absolute key for this as I then really work the keyboard. The hammering action has already damaged numerous regularly available commercial prosthetic products. That is one of the reasons why I wear my own wrist unit.||Hundreds, thousands.||10|
|Column||The thumb rests behind the index and middle fingers. The front of the fingers can be used to push a button, door bell or similar. Also, this is the recommended grip for dressing.||I just push with the Becker hand (in rest it contains a useful index and middle finger shape for pushing) or the hook. Not so important quantitatively though.||Few times.||2|
|Mouse||The grip holds (thumb, fingers) and clicks (index) the mouse.||I use a two button wheel mouse with my (left, anatomical, human) hand. I do not use the mouse with the prosthetic because I really need mousewheel, and three button options, a lot. The BeBionic 3 hand would not cover my mouse control requirements.||Hundreds, thousands.||N. A.|
|Precision grips||There are two variations of precision grip: precision open, where the remaining fingers stay fully open, and precision closed where the remaining fingers close fully. Precision is the best grip for picking up and manipulating small objects quickly and accurately. Initially both the index finger and thumb close, the thumb pauses midway whilst the index finger continues to close to grip the object. This makes it easier to position the fingers to pick up smaller objects.||Just like the pinch grip, this is the naturally occurring hook or Becker hand grip style. So that is what my terminal devices also do and they do it really well.||50-100||3|
|Hook grip||Partially closed power grip is used to carry shopping bags or briefcases.||My hook and the Becker hand that locks its grip to do just that (bags, briefcases) do this quite well.||5-10||3|
|Finger adduction||Used to hold a toothbrush.||A hook or Becker hand can hold a toothbrush without problem. But it is really an infrequent issue.||3-5||1|
Overall, the BeBionic 3 offers grip patterns that are in part very relevant, from my view, to keep my overuse problems down.
However, the most important grips are - without any surprise and due to their long development and product refinement cycles - already available with Becker hands and any type of Hosmer or other hooks.
In comparison to a myoelectric socket, my body powered arms contains some very relevant features: my minimal weight carbon fiber body powered socket sits on an Ohio Willow Wood Alpha gel liner that connects to an Ossur Icelock pinlock system. So I do have maximal comfort and stability with a body powered aŕm covering the grips that I need most often to keep my own overuse minimal. Also, my constant very had repetitive bangs and pulls required a peculiar wrist unit, and so I wear a self constructed high tech wrist unit. Last but not the least, new prosthetic hands are always nice to see in action - but it will be very hard to match my own equipment in terms of speed and agility. Very very hard.
The thing that the BeBionic 3 brings to the table is a really good appearance. It certainly looks great. And with greatly added stability, it most certainly seems to be one of the best "bionic" hands there are out there right now.