RSI-Relief

People suffering from Carpal Tunnel Syndrome and other repetitive strain injuries often experience a loss of hand dexterity. With the sensory feedback from fingers dulled by pain or nerve damage, simple tasks such as brushing your teeth, combing your hair, or grasping a pencil may suddenly become difficult or even impossible.

But the Arizona State University News reports that thanks to a new five-year, $1 million grant from the National Institutes of Health, there may soon be hope,According to Marco Santello, an associate professor of kinesiology at Arizona State University:

The goal of the project is to fill in the knowledge gaps that exist concerning CTS and its effect on hand dexterity. CTS currently affects the quality of life for 6 to 14 million people in the U.S.

“Our main goal is to quantify the effect of CTS on hand control and grasping,” Santello said. “If you have CTS, even in its mild severity, you have problems learning how to control digit (finger) forces as a function of object properties such as weight and texture.”

Santello said that current clinical methods of determining the severity of CTS focus on the state of a person’s median nerve, which conveys sensation from the thumb, index, middle and part of the ring fingers, as well as motor commands to some of the hand muscles. One of the electro-diagnostics tests of the median nerve, where an electrical stimulus is administered to measure how fast the nerve can transmit the stimulus, tells doctors if the nerve is healthy or, alternatively, the extent of its degeneration. But it doesn’t provide information on the person’s ability to control the hand.

“It is difficult to correlate that measurement with a person’s dexterity,” Santello said. “It might say, yes I have mild CTS, but how much does that impact my dexterity, my ability to manipulate?”

This information is important because it could be used to measure the effectiveness of surgical intervention and physical rehabilitation to improve hand function.

Santello explained that a person with CTS might have intact sensory feedback from one and a half of the five fingers on that person’s right hand, for example. But when that person manipulates objects, the brain receives and integrates sensory inputs from all digits engaged in the task, so that movement and forces of the digits can be properly coordinated.

With the majority of the sensory inputs now not properly working, the brain has to compensate for the insufficient data coming to it. Often that means over grasping an object to secure it before picking it up. Over grasping can result in an even greater compression of the median nerve, resulting in greater severity of CTS.

“If you are exerting more force than you need on a daily basis and you are not fully aware of it, it is likely to make CTS worse because you keep adding compression to the nerve,” he said. [Read more]

The project hopes to improve understanding of how tactile feedback is utilized by the central nervous system.

If you suffer from CTS, how has it affected your hand dexterity?