• Gait Assessment [ Time Frame: Pre-treatment, Post-treatment ] [ Designated as safety issue: No ]
• Stroke Impact Scale [ Time Frame: Pre-treatment, Post-treatment ] [ Designated as safety issue: No ]
• Spasticity (Modified Ashworth) Scale [ Time Frame: Pre-treatment, Post-treatment ] [ Designated as safety issue: No ]
• Biodex Isokinetic Strength Measurements [ Time Frame: Pre-treatment, Post-treatment ] [ Designated as safety issue: No ]
• Strength Test [ Time Frame: Prior to each treatment session ] [ Designated as safety issue: No ]
• Joint Position Test [ Time Frame: Prior to each treatment session ] [ Designated as safety issue: No ]
• Passive Motion Test [ Time Frame: Prior to each treatment session ] [ Designated as safety issue: No ]

The AMES device a investigational device which cyclically rotates the ankle while muscle vibrators stimulate sensory receptors in the muscles opposite to the joint being rotated. In effect, the device provides assisted movement of a joint and enhanced sensation of that movement. The purpose of this study is to determine whether stroke survivors who remain unable to move normally more than one year after their stroke will be able to walk and move their affected leg significantly better after treatment with a new robotic therapy, the AMES device.

Each year, more that 600,000 U.S. citizens survive a major stroke. Following acute treatment, 30-40% of these survivors sustain permanent motor disabilities. Within weeks of the stroke, surviving patients begin physical therapy to restore motion to affected limbs. Some recover completely, but many do not. There are over 5 million stroke survivors in the U.S. who did not recover completely and many are severely incapacitated for the remainder of their lives.

The hypothesis underlying stroke rehabilitation with AMES is that, in many stroke victims, the damage to the brain disrupts one or more feedback loops that connect the proprioceptive receiving areas of the primary somatosensory cortex to the primary and pre-motor cortex. Without proprioceptive information feeding into the motor output center, the brain cannot "locate" the muscles needed for movement to occur. The hypothesis behind AMES rehabilitation is that synchronous and repetitive activity of the input and output areas of the cortex stimulate the reorganization of brain pathways, thereby closing the feedback loop disrupted by the stroke.

Our research objective is to develop procedures to rehabilitate those stroke patients who, through conventional therapies, were not brought to a level of maximal recovery. The aim of the study is to obtain a set of data from a total of 16 chronic stroke subjects, all with lower extremity disability, between the ages of 18-75, using the AMES robotic device in a rehabilitation clinic. Each subject will participate in 10 weeks of therapy, 3 days per week, 30 minutes per day. The data collected will be analysed to quantify the extent to which a combination of robot-assisted exercise and muscle vibration induce secondary recovery from stroke in the lower extremity.

• Stroke
• Cerebrovascular Accident

Inclusion Criteria:

• At least 12 months post-stroke
• Cognitively and behaviorally capable of complying with the regimen
• Functioning proprioception
• Less than 50% of normal strength in the affected ankle, but able to stand with ot without assistive devices

Exclusion Criteria:

• Fractures of treated limb resulting in loss of range of motion
• Spinal cord injury
• Deep vein thrombosis
• Peripheral nerve injury or neuropathy in the affected limb with motor disability
• Osteoarthritis limiting range of motion
• Skin condition not tolerant of device
• Progressive neurodegenerative disorder
• Uncontrolled seizure disorder
• Botox treatment within the last 5 months
• Baclofen pump