1. Bimanual Coordination Assessment Using Prosthetic Simulators
Chris Copeland, James Pierce, Keaton Young, & Jorge Zuniga Department of Biomechanics, University of Nebraska at Omaha

2. Introduction As of 2005, roughly 1.6 million people with limb loss.1
Roughly 3.6 million by
CDC estimates 1,500 babies are born per year with upper limb reductions.2
Non-mandatory reporting in the U.S.
Estimated that 56% of prosthesis users reject new limb.2
2050 – 7.7 Omahas
Credit: Greenville Shriners Hospital

3. Introduction Why? Control difficulty or lack of functional use
We don’t know!
Control difficulty or lack of functional use
Regardless of prosthesis type.
Gap in literature describing the neurological and motor control mechanisms.
Lack of subjects
Low subjects → Low power
How do we alleviate this?
Prosthetic Simulators may be the answer

4. Introduction What is a prosthetic simulator?
Device designed to serve as a “functional homologue” of a traditional prosthetic device.
Can used in healthy typically developing individuals to observe the neurological mechanisms of prosthetic use.

5. Introduction
The purpose of this investigation was to determine the efficacy of prosthetic simulators.
Examine bimanual coordination through movement asynchrony.
We hypothesized that bimanual coordination would be significantly reduced in children using simulators and children with upper limb deficiencies (ULD), compared to controls.

6. Methods
Groups
ULD: Children with upper limb deficiencies using body powered prosthetics (n = 5)
TD-Control: Typically developing children age and sex matched to ULD group. (n = 5)
TD-Simulator: Children from TD Group, now using a prosthetic simulator on their left hand.
Typically Developing (TD)
N =5
Upper Limb Deficiency (ULD)
N =5
TD - Simulator
TD - Control

7. Methods Task – Bimanual Coordination Tray
Bimanual reaching tasks were used to assess overall coordination and limb synchrony.
Each subject started from a standardized position.
Then, reached forward to grasp an instrumented trap and move it to ledge.
Finally, the subjects returned their hands to the standandized resting position.
Movement times were noted for component of the task.
Hand-to-Tray
Tray Transfer
Hand Return
Overall Task

8. Results
Mean movement time of all task components illustrated to the right.
Two independent variables:
Hand (Preferred/Non preferred)
Limb Condition (Control/Sim/ULD)
Two-way analysis of variance yield significant main effects of limb condition.
Positive values indicate right-limb leading.
Negative values indicate left-limb (prosthetic/simulator) leading.

9. Discussion
Movement asynchrony not significantly different comparing control to TD-Sim or ULD for any component.
General trends of ULD group having higher asynchrony and leading with their preferred limb.
TD Sim tended to lead with their non-preferred.

10. Using movement time as an indirect measure of coordination:
ULD group significantly worse than TD- Simulator and TD-Control
TD-Simulator significantly worse than TD- Control.
Overall, partial support of hypothesis.
Further investigation needed with more subjects.
Limitations such as learning effects, prosthetic use history, etc. must be accounted for.

11. Thank you! Questions?

12. References
K. Ziegler-Graham, et al. Arch. Phys. Med. Rehabil., 89, 3, 422–429, 2008
Krebs DE, Edelstein JE & Thornby MA, Phys Ther, 71, , 1991.
E. A. Biddiss Prosthet. Orthot. Int., 31, 3, 236–257, 2007.