Myoelectric prosthetics hands
Find out all you need to know about myoelectric-controlled prosthetic solutions from the world leader in upper limb prosthetics.
For upper-limb amputees, myoelectric-controlled prostheses offer the ultimate combination of function and natural appearance. Designed to mimic human anatomy and motion, electronic components are the closest alternative to an anatomical hand or arm.
Thanks to constantly advancing technology, the latest prosthetic systems feature astonishing capabilities:
Elbows that flex and extend with muscle signals so you can reach for a beverage and bring it to your lips
Wrists that bend and rotate, allowing you to position objects for convenient viewing and handling
Hands that can lug a suitcase or hold an egg without cracking it
Thumbs that can change orientation to multiple hand positions
What is a Myoelectric prosthesis?
“Myoelectric” is the term for electric properties of muscles. A myoelectric-controlled prosthesis is an externally powered artificial limb that you control with the electrical signals generated naturally by your own muscles.
Hand, wrist and elbow myoelectric components are available. With amputations above the elbow, a hybrid prosthesis may combine myoelectric-controlled components with body-powered components to control shoulder and/or elbow function. A skin-like glove covers the prosthesis for a natural appearance.
Prosthetic hands and terminal devices
Because upper-limb prostheses can end with a variety of artificial replacements for a hand, prosthetists refer to this broad assortment as terminal devices. With myoelectric prostheses, the options generally fall under these two categories:
The human hand is one of our most complex body parts. A perfect interplay of nerves, tendons, muscles and bones makes it a remarkably versatile, precision instrument. Recreating as many of its numerous functions as possible is one of the greatest challenges for medical technology.
Myoelectric hands may feature:
A variety of sizes for children as young as 18 months and adults
A cosmetic glove in a variety of skin colors or a transparent glove to show the hi-tech inner workings
A hand for amputation at or below the wrist
Ability to carry heavy loads (up to a set limit)
Aluminum construction for lighter weight
A manually adjustable thumb
A positionable thumb, driven by a separate motor, which allows for multiple grip patterns
A neutral position for a natural look and action while walking or at rest
Powerful grip force and grip speed
Grip force and grip speed proportional to the strength of the myoelectric signal
A virtual switch that requires a slightly stronger myoelectric signal to open the hand after applying maximum gripping force
A sensor in the thumb that detects friction caused by objects slipping and automatically tightens the grip to prevent dropping
A slip-clutch to quickly release the hand’s grip in an emergency
Passive functions to resist weight bearing and other loads
Multiple grip options, such as pinching with the thumb and index finger, power grip for handles, open palm for holding a platter, opposition power grip for grasping cylindrical object with a big diameter, three-point grip with thumb, index finger and middle finger, and holding flat objects between two fingers
A handshake function that automatically sets the grip force
A choice of multiple programs to tailor the speed and build-up of grip force to individual abilities and requirements
Individually powered fingers with movable joints
Ability to extend the index finger to point or press a button
Fingers that spread when the hand opens and come together when the hand closes—so you can hold credit cards or bills between your fingers
Terminal devices: Greifer
A Greifer is a powerful, highly functional terminal device made by Ottobock. Designed to perform gripping applications, it excels at manual labor and other tasks. Features may include:
Control of grip speed and grip force
A flexible joint for convenient positioning
Adjustable gripping surfaces
Easy to swap out with other myo hands
Powerful grip force
Myoelectric-controlled wrists make it easier to grip and control objects close to the body. They also limit compensating movements you may make with your shoulder and the rest of your body—allowing you to move more naturally.
Capabilities may include:
Multiple positions of flexion and extension in set increments
Quick detachment for changing between terminal devices
A flexible mode that mimics natural movement with a spring-loaded mechanism that returns the wrist to neutral position
Progressive resistance in flexible mode
A rigid mode that locks the flexion or extension in increments for holding and carrying objects
360-degree rotation, with stops at multiple positions
Myoelectric-controlled elbows, which typically include a forearm, flex and extend so you can do more without unnatural compensating movements. Capabilities may include:
Bending the elbow in set increments
Continuous adjustment—variable bending of the elbow—for more natural movement and exact positioning of the prosthetic hand
Locking and unlocking for reliable loading up to a certain weight limit
Automatic balance that creates a natural arm swing during walking
Patient-adjustable counterbalance that makes the arm feel lighter
The most natural control available
Groundbreaking prosthetic technology and new surgical techniques combine to create the most natural upper-limb prosthetic system to date. With targeted muscle reinnervation (TMR), you intuitively control the prosthesis—just like with a sound limb.
Following an amputation, peripheral nerves still carry orders for motor control from your brain, but the commands never reach their destination in the amputated muscles. TMR redirects those nerve signals to other muscles that can control the prosthesis. In a surgical procedure, nerves in the residual arm are reattached to a healthy muscle elsewhere in the body, such as a chest muscle. Then, when the patient wants to move the arm, the nerve signals originally used for arm movement cause the chest muscle to contract. Electrodes in the chest muscle sense the electrical activity and send a control signal to the prosthesis.
In effect, you move the prosthesis just by choosing to move it. With a conventional myoelectric-controlled prosthesis, you have to think about engaging a certain muscle to prompt a movement unrelated to that muscle. With a TMR prosthesis, the nerve signals that your body originally used for arm, wrist, and hand movement are actually used to control your prosthesis. TMR lets you make multiple movements of the prosthetic arm simultaneously without stopping to think about each action.
You may be a candidate for a TMR prosthesis if you:
Have an above-elbow or shoulder-disarticulation amputation
Had the amputation no more than 10 years ago
Are highly motivated and ready to cope with a long-term process
TMR surgery is followed by intensive therapy, which could last for several weeks or several months. Adjustment to the TMR prosthesis also involves substantial physical and occupational training. For help in finding a qualified surgeon or prosthetist, contact Ottobock.
Is a Myoelectric prosthesis right for you?
A myoelectric-controlled prosthesis may be a good choice if you:
Had an amputation above the fingers
Have the ability to control the prosthesis using your own muscle nerves in or near your residual limb
Want the best combination of function and natural appearance
Want a solution that will give your greater function for everyday tasks
Currently have a body-powered prosthesis and:
Want more grip force
Want greater range of motion and a larger ‘functional envelope’ (area of use)
Find your harness uncomfortable or restrictive
Experience symptoms of overuse or nerve entrapment syndrome in your intact arm
Want a more natural-looking prosthesis
Want relief from back pain related to unbalanced posture
How to get one: consult a certified practitioner
Conversations with your prosthetist will guide the decision on a prosthetic system. Make sure the prosthetist clearly understands your goals and challenges. Learning about myoelectric prostheses will help you discuss the options and advocate for your preference.
If you are interested in Ottobock’s MyoBock myoelectric prosthetic system, talk to your prosthetist or contact a certifed practitioners who has completed training with Ottobock.
Make sure you ask about the prosthetist’s experience with myoelectric prostheses.Based on your goals, muscle strength, occupation and activities, your prosthetist will prescribe the solution that best fits your needs
An experienced prosthetist understands that your diagnosis and your clinical needs must be documented to justify the components in the prescribed prosthesis as medically necessary, whether for safety or to achieve your potential for a higher activity level.