WHAT HAPPENS TO THE BRAIN DURING A STROKE
A stroke is caused by either a blockage of a blood vessel or bleeding in or around the brain, which results in a lack of oxygen to the brain and the death of brain cells. The residual physical effects of the loss of brain cells will depend on the area of the brain that was affected.
One of the functions of the brain is sending messages to our muscles to move in a coordinated way to complete functional activities. More than half of stroke survivors experience a lasting hemiparesis due to the damage to the brain.  Hemiparesis is weakness on one side of the body, and depending on what brain cells died will determine which pathways to specific muscles will be affected. Stroke is the leading cause of long term disability in the United States. 
HAND FUNCTION AND ROBOTICS
We often don’t appreciate the complexity of what the arm and hand are able to do. It’s incredibly complicated. There are 20 joints in the hand alone, and the joints of the arm are able to move in over 40 different directions. Add in the degrees of freedom of each joint, the coordination required to grade movement, the alignment of joints, and exertion of force and you’ve got a very complex physical system you’re trying to repair after a stroke. That doesn’t even take into account all the other requirements of a task, such as your visual perception, your sensation, and your understanding of where your body is in space. Spasticity also develops in stroke, which makes movement of the joint even more difficult.
Robotics used in rehabilitation has made a lot of progress in the last 10 years, primarily with devices to assist with walking. Upper extremity robotics in stroke range from full assistance with movement to tracking active movement. While they are both important, there seems to be a disconnect between designers and clinicians in the purpose of the device.
Of course it would be awesome if you could put on a robotic glove and suddenly you would be able to do all the things you were able to do before a stroke, but it just doesn’t work like that. Even if they were to develop an exoskeleton that could capture the motor movement parameters of the arm, it wouldn’t be able to feel and capture the proprioceptive and visual feedback that the neurologically intact arm provides.
But the brain is an amazing thing! Even though we can’t repair the damage to the brain, the brain has the capacity to rewire itself. This is called neuroplasticity.
WHAT WE KNOW ABOUT REHABILITATION IN STROKE
There are several evidence-based rehabilitation strategies in stroke that tap into neuroplasticity including repetitive task practice, constraint-induced and modified constraint-induced movement therapy, virtual reality, mirror therapy, and strengthening and exercise.  Many of the techniques overlap in their concepts, and while research is still determining the specifics of which components of these interventions makes the biggest difference in hand use and function, it’s clear that you have to put the work in to make neurological changes.
The commonality for all of the above interventions is frequent repetitions of movement. We don’t know the magic number of repetitions, but it has to be enough to create a signal from the brain to the muscle. Imagine you’re trying to build a road from point A to point B through a pile of dirt with just a truck. The first time you drive the truck over it’s going to be slow and kind of a bumpy ride, but then you do it again and again. Each time your truck goes over the path, it creates a smoother road and gets easier. This is how you train your brain to send messages to the muscles. Your brain sends a signal to the muscle to move. The more you do it, the easier it gets. It can be a foreign feeling to try to isolate a muscle movement because for everyday tasks we use a combination of muscles and joints to complete the requirements of the task. Creating those neural pathways to the muscles is the first step of being able to use the muscles of arm together.
You could sit there and move your hand and arm 200 times everyday for each motion, but in practical application of rehab this just doesn’t happen. We also know that initiating movement for a purpose is more likely to develop neuroplasticity than straight repetitions alone. 
It’s training your brain to create those pathways to your muscles, and it does it in a way that’s motivating and tracks your progress. A typical session will have you complete 200-300 repetitions. It doesn’t move your hand for you, you have to do the work. If you have visible movement of your wrist, forearm, and/or fingers, there is a message that’s trying to get from the brain to the muscle. The algorithm can create that “just right challenge” to push you just a little further to really dig into making that path. A robotic hand that moves for you and doesn’t make you work for it, isn’t sending the truck down the road.
CONTINUING THE REHABILITATION JOURNEY
Repetitive movements are only one piece of the puzzle when it comes to stroke rehabilitation. Your brain can create pathways to the muscles, but all functional activities require a variety of muscles and joint movements. You also have to practice the functional task you want to achieve over and over again until your brain can learn to do it without thinking about it. It’s not just about improving your movement, it’s about being able to do the things that give you quality of life. You don’t have to have full range of motion of each joint and muscle to be able to do your favorite things, there are a lot of different ways to accomplish a task.
Depression and a decrease in social activity are common in people with stroke and impact their quality of life . Discover the activities that make you happy and give you life. As we age we all have to re-evaluate what’s important to us and grieve the things that are harder than they used to be. But that doesn’t mean we can’t find new versions and new things that make us happy. Regardless of the function of your hand, you can live a beautiful, fulfilling life.
Here at Neofect, we're committed to supporting you in your rehabilitation journey. If you have had a stroke and are looking for an effective solution for your rehabilitation needs, please look into NEOFECT's line of Smart Rehabilitation Solutions.
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- Yue Z, Zhang X, Wang J. (2017) Hand Rehabilitation Robotics on Poststroke Motor Recovery. Behavioral Neurology
- Benjamin, E. J. et al. (2019) Heart Disease and Stroke Statistics—2019 Update: A Report From the American Heart Association. Circulation
- Nilsen, D. M., Gillen, G., Geller, D., Hreha, K., Osei, E., & Saleem, G. T. (2015). Effectiveness of interventions to improve occupational performance of people with motor impairments after stroke: An evidence-based review. The American Journal of Occupational Therapy, 69(1), 1-5A.
- Opara, J. A., & Jaracz, K. (2010). Quality of life of post-stroke patients and their caregivers. Journal of medicine and life, 3(3), 216–220.
All content provided on this blog is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. If you think you may have a medical emergency, call your doctor or 911 immediately. Reliance on any information provided by the Neofect website is solely at your own risk.
- Clarice Torrey, OTR/LClarice is an occupational therapist, product designer, and health writer based out of San Francisco, CA. Clarice works for RAD Camp as a Community and Product Manager.