News Release

Studying the biomechanics of the human thumb

Grant and Award Announcement

Cornell University

Francisco Valero-Cuevas, assistant professor of mechanical and aerospace engineering at Cornell University, has been awarded a $239,992 research grant by the Whitaker Foundation to study the human thumb.

He is principal investigator at the Neuromuscular Biomechanics Laboratory at Cornell's Sibley School of Mechanical and Aerospace Engineering, which is dedicated to understanding the biomechanics, neuromuscular control and clinical rehabilitation of hand function. The funding will advance Valero-Cuevas's research on the biomechanics of the thumb in which he marries anatomical studies with mathematical analysis.

The Whitaker grant will enable Valero-Cuevas to study the thumb's muscles, joints and tendons. This will aid further understanding of the thumb's complex musculoskeletal structure, and should improve surgical procedures for thumb and hand injuries.

The researcher notes that there is no complete model of hand function, which can hamper diagnosis and treatment of hand injuries. For example, nerve damage at the wrist can paralyze three small muscles at the base of the thumb and severely impair the ability to function normally.

Valero-Cuevas's previous research found that weakness of the forefinger from paralysis does not always arise from the inability to produce large fingertip forces. Instead, small, weaker muscles are necessary to steer the large fingertip force vectors produced by the stronger muscles toward the directions necessary for pinch and grasp. He hopes to prove that the same holds true for the thumb.

For his thumb research, Valero-Cuevas will use cadaver hands. The tip of the thumb is attached to a dynamometer, a device that measures every push and pull the thumb makes in any direction. As computer-controlled actuators tug on different strings, the dynamometer measures the resulting force of the thumb. Nearly half a million hands undergo surgery each year, according to the American Academy of Orthopedic Surgeons. Surgeons often perform a tendon transfer in which a tendon attached to another part of the hand is cut, rerouted and reattached to the base of the thumb, basically giving the thumb a new muscle, says Valero-Cuevas.

Injuries to the hand, wrist and forearm, the place where most of the muscles, nerves and tendons that control the thumb are found, numbered more than 8 million in 1999, the latest year such data was available.

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Valero-Cuevas graduated from Swarthmore College in 1988, with a B.S. in engineering. After spending a year in the Indian subcontinent as a Thomas J. Watson Fellow, he joined Queen's University in Canada where he earned his M.S. in mechanical engineering. He earned his Ph.D. in mechanical engineering from Stanford University in 1997. As a research associate at Stanford he focused on developing experimental methods that use optimal control to improve the surgical restoration of hand function following spinal cord injury and peripheral nerve injuries. He joined the Cornell faculty in 1999. He also has close ties with the Hospital for Special Surgery in New York City.

Related World Wide Web sites: The following sites provide additional information on this news release. Some might not be part of the Cornell University community, and Cornell has no control over their content or availability.

o Neuromuscular Biomechanics Laboratory: http://www.mae.cornell.edu/nmbl/


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