Everyone experiences stiff muscles from time to time, whether after a rigorous workout, in cold weather, or after falling asleep in an unusual position. People with cerebral palsy, stroke and multiple sclerosis, however, live with stiff muscles every single day, making everyday tasks such as extending an arm extremely difficult and painful for them. And since there isn’t a foolproof way to objectively rate muscle stiffness, these patients often receive doses of medication that are too low or too high.
Now, an interdisciplinary team of researchers at the University of California San Diego and Rady Children’s Hospital has developed new wearable sensors and robotics technology that could be used to accurately measure muscle stiffness during physical exams. “Our goal is to create a system that could augment existing medical procedures by providing a consistent, objective rating,” said Harinath Garudadri, a research scientist at the university’s Qualcomm Institute and the project’s lead investigator.
“Many clinical exams and procedures are very subjective and rely on measurements that are done with a physician’s hands,” said Andrew Skalsky, director of the division of Rehabilitation Medicine at Rady Children’s Hospital. “We often make major medical decisions and diagnoses based on touch and feel. With this technology, we can start to develop objective measurements for subjective processes.”
The level of muscle stiffness, known as spasticity, is typically evaluated using a six-point rating scale called the Modified Ashworth Scale. This scale is the current hospital standard, but it is subjective and often yields ratings that vary from one doctor to another. These ratings help dictate the dose of medication patients are prescribed to manage their spasticity. Inconsistent and inaccurate ratings can either lead to dangerous overdose or ineffective treatment as a result of doses that are too low.
Patient feedback can also skew these ratings, Skalsky said. “Sometimes, patients think that they aren’t getting enough medicine and end up being put on a higher dose than they should actually be on. That’s thousands of dollars’ worth of medicine that could potentially be saved.”
Garudadri and Skalsky teamed up with electrical engineers and neuroscientists at UC San Diego to develop a glove equipped with sensors that is a more reliable tool and will enable doctors to come up with objective, accurate and consistent number ratings when evaluating spasticity in patients undergoing treatment.
The device is built on a regular sports glove that a doctor can wear…