Millions of people worldwide suffer from diseases that lead to paralysis through disruption of signal pathways between the brain and the muscles. Neuroprosthetic devices are designed to restore lost function and could be used to form an electronic 'neural bypass' to circumvent disconnected pathways in the nervous system. It has previously been shown that intracortically recorded signals can be decoded to extract information related to motion, allowing non-human primates and paralysed humans to control computers and robotic arms through imagined movements. In non-human primates, these types of signal have also been used to drive activation of chemically paralysed arm muscles. Here we show that intracortically recorded signals can be linked in real-time to muscle activation to restore movement in a paralysed human. We used a chronically implanted intracortical microelectrode array to record multiunit activity from the motor cortex in a study participant with quadriplegia from cervical spinal cord injury. We applied machine-learning algorithms to decode the neuronal activity and control activation of the participant's forearm muscles through a custom-built high-resolution neuromuscular electrical stimulation system. The system provided isolated finger movements and the participant achieved continuous cortical control of six different wrist and hand motions. Furthermore, he was able to use the system to complete functional tasks relevant to daily living. Clinical assessment showed that, when using the system, his motor impairment improved from the fifth to the sixth cervical (C5-C6) to the seventh cervical to first thoracic (C7-T1) level unilaterally, conferring on him the critical abilities to grasp, manipulate, and release objects. This is the first demonstration to our knowledge of successful control of muscle activation using intracortically recorded signals in a paralysed human. These results have significant implications in advancing neuroprosthetic technology for people worldwide living with the effects of paralysis.

TROKE IS A MAJOR HEALTH issue for women. 1,2 Cerebrovascular diseases are the third leading cause of death in the United States 3 and are the leading cause of adult disability. The Women's Health Initiative (WHI), beginning in the early 1990s was designed to examine a number of factors affecting the health of postmenopausal women. 4 Recently 1 arm of the WHI, the clinical trial of estrogen plus progestin, was terminated 3 years before its planned completion date because its harmful effects outweighed its benefits.

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ClinicalTrials.gov Identifier: NCT00000611.

Objective Osteoarthritis (OA) clinical practice guidelines identify a substantial therapeutic role for physical activity but objective information about the physical activity of this population is lacking. We objectively measured physical activity levels of adults with knee OA and report the prevalence of meeting public health physical activity guidelines. Methods Cross-sectional accelerometer data from 1111 adults with radiographic knee OA aged 49 to 84 years participating in Osteoarthritis Initiative accelerometer monitoring ancillary study were assessed for meeting the aerobic component of the 2008 Physical Activity Guidelines for Americans (≥150 minutes/week in episodes≥10 minutes). Quantile regression was used to test median gender differences in physical activity levels. Results Aerobic physical activity guidelines were met by 12.9% of men and 7.7% of women with knee OA. A substantial 40.1% of men and 56.5% of women were inactive, doing no moderate-to-vigorous (MV) activity over 7 days that lasted 10 minutes or more. Although men engaged in significantly more MV intensity activity (20.7 vs. 12.3 average daily minutes) they also spent more time in no or very light intensity activity (608.2 vs. 585.8 average daily minutes) than women. Conclusion Despite substantial health benefits from physical activity, adults with knee OA were particularly inactive based on objective accelerometer monitoring. The percentages of men and women who met public health physical activity guidelines were substantially less than previous reports based on self-reported activity in arthritis populations. These findings support intensified public health efforts to increase physical activity levels among persons with knee OA.