Assessing Force Feedback With the SoftHand Pro

The human sensorimotor control system uses both feedforward planning and sensory feedback
information, in order to actuate the musculoskeletal system and interact with the external
environment, e.g. when modulating grip force for various object properties. As a result, lack
of sensory input, as in the case of motor impairments or amputations, can dramatically affect
activities of daily living (ADLs). The contribution of the proposed research will be to test
the effectiveness of a novel, non-invasive prosthetic technology in delivering sensory
information. The investigators' approach is "modality matching," in that it produces a
sensation in the user similar to the type of information to be transmitted. Specifically, the
approach will combine the Soft Hand Pro (SHP), an anthropomorphic, myoelectrically controlled
prosthetic hand, with an upper limb force feedback device (CUFF) to provide patients with
transradial amputations with grasp force (pressure) information.

Inclusion Criteria:

1. age > 18 years.

2. no prior experience with the CUFF device.

3. history of transradial limb loss.

Exclusion Criteria:

1. amputation for less than 6 months

2. clinical history of brachial plexopathy, cervical radiculopathy or polyneuropathy

3. orthopedic, joint degeneration (i.e., arthritis, verified by x-ray) affecting the hand
or cervical spine that severely limit upper limb function

4. visual problems that would interfere with the grasp task

5. co-existing central nervous system disease with symptoms that limit upper extremity
function (e.g., multiple sclerosis, motor neuron disease, myasthenia gravis,
Parkinson's disease, dystonia) revealed in medical history

6. significant rigidity as assessed through range of motion testing

7. active psychiatric illness

8. significant cognitive impairments (a score < 24 on the Mini-Mental State Examination)

9. use of medications that might affect sensory and/or motor functions