Motion Control’s Utah Arm is a microprocessor-controlled electric elbow that is compatible with multiple input systems, wrist components, and bionic hands or other terminal devices.
What’s On This Page?
- A Quick Look at the Utah Arm
- Basic Mechanics and Control System
- Proportional Speed Control
- Wrist Design
- Lift Capacity & Strength
- Water and Dust Resistance
- User Software
- User Feedback Survey & Results
- Considerations Before Buying a Utah Arm
- Related Information
A Quick Look at the Utah Arm
As is the case with most of the electric elbows we review, there are few recent videos available to demonstrate the Utah Arm’s capabilities. The best one that we can find is this video from 2007, which is still relevant:
We’re not sure why there are so few videos on electric elbows. Perhaps it’s because they tend to be viewed more as components of bionic solutions rather than solutions in their own right. However, in addition to proving a powered elbow joint, they can also be used as a control platform for other components.
Basic Mechanics and Control System
Here are the Utah Arm’s basic mechanical and control features:
- The elbow can both flex and extend. When flexing, the elbow can actively lift as much as one kilogram, which is significantly less than most of its competitors. However, the Utah is also lighter than most of its competitors.
- Depending on the model, the Utah has a friction brake that can silently lock the elbow in any position throughout the range of motion. This is used when passively carrying loads up to 4.5 kgs and is activated by the user by holding the elbow stationary for a specified amount of time.
- The elbow also has a second type of lock that automatically engages when carrying a load greater than 4.5 kgs.
- Depending on the model, the elbow has a Silent Freeswing mode that allows it to swing freely while walking. This mirrors the swing of a natural arm.
- The Utah contains two microprocessors and can act as the master controller for the elbow, a wrist component, and a bionic hand or another terminal device. Alternatively, it can surrender control to other input systems such as Coapt Engineering’s Gen2 or Infinite Biomedical Technologies’ Sense pattern recognition systems.
- In addition to myoelectric control, the Utah also supports the use of certain transducers and switches.
As with most of its competitors, the Utah Arm is a mature device that has refined both its basic mechanics and its features over time.
Proportional Speed Control
The Utah fully supports proportional speed control.
The Utah can use different wrist components depending on the selected bionic hand or terminal device.
Lift Capacity & Grip Strength
The Utah can lift 1 kilogram by flexing at the elbow (arm curl), which is lower than most of its competitors. It also has a passive lift capacity of 22 kilograms with the elbow fully locked.
The Utah Arm is described by Motion Control as “having high-strength plastic” with “structural components that have withstood the test of time, as demonstrated over 30 years of service to upper extremity wearers”.
However, as explained in the next section, this device is not water- or dust-resistant and can be damaged even by perspiration. Additionally, while it is capable of passively supporting a load up to 22 kilograms, the device’s User Guide warns that attempts to load the arm with more than 22 kgs may result in damage. By comparison, to avoid damage, Ottobock’s ErgoArm will release its locking mechanism if overloaded.
In general, we think it is wise to view all electric elbow devices as relatively fragile.
Water and Dust Resistance
The Utah is not water- or dust-resistant. Even perspiration can severely damage the arm if it enters the electronic systems.
Depending on the model, the Utah Arm comes with up to five battery packs. Each battery pack provides sufficient energy to operate the elbow, wrist, and a terminal device.
The duration of use per battery pack varies significantly depending on usage and the types of components that make up the arm system.
When one battery pack runs out of power, users can quickly swap in another.
Note that some bionic hands may require a supplemental battery, which a prosthetist will have to build into the arm socket.
Motion Control provides a software application called MCUI App. The primary use of this software is to allow prosthetists to configure the Utah.
However, the app also allows users to calibrate the Utah Arm on their own using the Auto-Cal feature. Note, as these calibrations will replace those configured by the prosthetist, users should use Auto-Cal only at the direction of their prosthetist.
Unfortunately, we do not yet have reliable information on the net cash price to the consumer for a typical solution involving the Utah Arm.
If you have this information, please write us through our contact form.
The Utah comes with a standard two-year manufacturer’s warranty.
Users can pay to extend this warranty by an additional two years.
There do not appear to be any mandatory service obligations under the warranty.
User Feedback Survey & Results
Are you or have you previously been a Utah Arm user? If so, please share your insights with others looking at this arm as a possible prosthesis.
We do not yet have a sufficient number of survey participants to publish fair and accurate results for the Utah.
As soon as we do, we’ll update this section.
Considerations Before Buying the Utah Arm
We have not yet formed an opinion of the Utah Arm. As is the case with many electric elbows, it has been on the market for many years and certainly seems like a solid option for above-the-elbow limb solutions.
We won’t have anything additional to say about it until we get sufficient user feedback.
For a list of competitive devices, see Current Options for Above-the-Elbow Bionic Arms.
For a comprehensive description of all current upper-limb technologies, devices, and research, see our complete guide.
Click here for more information on Motion Control.