The purpose of this study is to examine the relationship between reflexes in the leg and the presence of neuropathic pain. The researchers are recruiting 30 individuals with spinal cord injury (SCI) total, 15 individuals with neuropathic pain due to SCI and 15 individuals without neuropathic pain. For this portion of the study, there are 2 visits. The first visit will examine cutaneous reflexes in the leg. During the second visit, the study team will assess sensation in the leg and administer questionnaires about pain, functioning, and quality of life.

The purpose of the second part of the study is to examine the effect of reflex training in the leg to decrease neuropathic pain. For this, the researchers are recruiting 15 individuals with neuropathic pain due to spinal cord injury to participate in the reflex training procedure. The study involves approximately 50 visits with a total study duration of about 6.5 months (3 months for baseline and training phases followed by 1 month and 3 month follow-up visits).

The purpose of the first portion of this study is to gather feedback from clinicians on the usability of the current system and procedure, so the researchers can make reflex training more useful and usable for improving recovery after spinal cord injury or other nervous system injuries and diseases. The researchers are recruiting 20 therapists who have been actively practicing physical medicine and 30 adults with no known neurological conditions to test system usability and the reflex operant conditioning protocol. For this portion of the study, there are 5 visits. We will also recruit 15 adults with no neurological injuries, 15 adults with neuropathic pain, and 15 adults with non-neuropathic pain to participate in one visit to provide feedback on sensation caused by stimulating electrodes.

The purpose of the second part of the study is to validate the capacity of the system to change the size of the targeted reflex. For this the researchers are recruiting 25 individuals with chronic incomplete SCI who have spasticity in the leg to participate in the reflex training procedure. The study involves approximately 45 visits with a total study duration of about 6 months.

The study team is recruiting 20 adults with spasticity due to chronic stroke and 20 adults with no neurological injuries for a 4 day study over 1 week. In people with chronic stroke, one of the most common and disabling problems is spasticity (increased muscle tone or muscle stiffness). The purpose of this research study is to examine effects of dry needling on the nervous system (pathways between the muscle, spinal cord, and brain) in people with spasticity due to chronic stroke. Dry needling is a procedure in which a thin, stainless steel needle is inserted into your skin to produce a muscle twitch response. It is intended to release a knot in your muscle and relieve pain.

The total study duration is 4 visits over one week. The first visit will take about 1.5 hours, during which the study team will determine the best electrode placement and create a removeable cast of your arm or leg to aid in placing electrodes in the next visits. The second visit will take about 3 hours, during which dry needling will take place, and the fourth and fifth visits will take about 1.5 hour. During all visits you will be asked to participate in examinations of reflexes (muscle responses to non-invasive nerve stimulation) and arm/leg function.

We are currently recruiting volunteers who are interested in participating in a brain-spinal cord-muscle response training study that aims to better understand the changes that take place in the nervous system as a result of this type of training. After spinal cord injury, brain-to-muscle connections are often interrupted. Because these connections are important in movement control, when they are not working well, movements may be disturbed. Researchers have found that people can learn to strengthen these connections through training. Strengthening these connections may be able to improve movement control and recovery after injuries.

Research participants will be asked to stand, sit, and walk during the study sessions. Electrodes are placed on the skin over leg muscles for monitoring muscle activity. For examining brain-to-muscle connections, we use transcranial magnetic stimulation. The stimulation is applied over the head and will indirectly stimulate brain cells with little or no discomfort.

Participation in this study requires approximately three sessions per week for four months, followed by two to three sessions over another three months. Each session lasts approximately 1 hour. Participants will receive a mileage reimbursement.

Reflexes are important parts of our movements. When reflexes are not working well, movements are clumsy or even impossible. After stroke, reflex responses may change. Researchers have found that people can learn to increase or decrease a reflex response with training. Recently, we have found that rats and people with partial spinal cord injuries can walk better after they are trained to change a spinal cord reflex. Thus, learning to change a reflex response may help people recover after a nervous system injury. In this study, we aim to examine whether learning to change a spinal reflex through operant conditioning training can improve movement function recovery in people after stroke or other damage to the nervous system.

Reflexes are important parts of our movements. When reflexes are not working well, movements are clumsy or even impossible. Researchers have found that people can learn to increase or decrease a reflex response with training. Recently, we have found that rats with spinal cord injuries can walk better after they are trained to change a spinal cord reflex. Thus, learning to change a reflex response may help people recover after a nervous system injury. We are currently studying effects of spinal cord reflex training (e.g., a knee jerk reflex) in people in early adulthood. We hope that the results of this study will help us develop spinal reflex training as a new treatment to help people in early adulthood recover better after spinal cord injury or other damage to the nervous system.

Reflexes are important parts of our movements. When reflexes are not working well, movements are clumsy or even impossible. After spinal cord injury, reflex responses may change. Researchers have found that people can learn to increase or decrease a reflex response with training. Recently, we have found that rats with spinal cord injuries can walk better after they are trained to change a spinal reflex. Thus, learning to change a reflex response may help people recover after a nervous system injury. In this study, we aim to examine whether learning to change a spinal reflex through operant conditioning training can improve movement function recovery after spinal cord injury.

Over many years, we have learnt that the brain's connections with the spinal cord change in response to injury or training. Because brain-spinal cord (i.e., corticospinal) pathways are very important in movement control, restoring function of these pathways could help to restore useful movement after spinal cord injury (SCI). In this project, we hypothesize that operant conditioning training of the muscle response to non-invasive transcranial magnetic stimulation can strengthen the functional connectivity of corticospinal pathways and thereby alleviate movement problems in people with chronic incomplete SCI. This study will require about 38 visits over the first 3 months, and another 4 visits over an additional 3 months. Each visit will take about an hour.

Spinal reflexes take important part in our movement. After spinal cord injury (SCI), reflexes often change. For many years, researchers and doctors have assumed that abnormally acting spinal reflexes lead to movement problems, without clear scientific evidence. For example, in people who suffer spasticity, a common problem after SCI, walking is disturbed, presumably because stretch reflexes (e.g., knee jerk reflex) and some other reflexes are not working well. Yet, which reflex is causing a problem in what way has not been well understood. Such understanding is very important in developing and applying effective therapies for improving gait recovery after SCI. Therefore, in this project, we are studying spinal stretch reflexes and other reflexes during walking, to understand how these reflexes contribute to spastic gait problems in people with chronic incomplete SCI. Successful completion of this project will result in better understanding of spastic gait problems, which in turn, will help us develop more effective therapy application and improve the quality of life in people after SCI.