An observational study in Healthy, sponsored by National Institute of Neurological Disorders and Stroke (NINDS). Completed at 1 site in United States. Per ClinicalTrials.gov, last updated 2008-03-04.
Sponsored by National Institute of Neurological Disorders and Stroke (NINDS) · Observational
This study will test a spinal cord reflex called reciprocal inhibition before, during, and after learning a motor skill to see if the reflex becomes stronger by learning the movement. People learn new motor skills throughout their lives. At first, performing a new skilled movement such as riding a bicycle takes effort and is clumsy, but with practice, it becomes relatively automatic. The motor cortex (a part of the brain) is very active when a new skilled movement is learned, but becomes less active when the movement is over-learned. This study will determine whether the spinal cord helps coordinate the pattern of activity between groups of muscles once a motor skill is learned.
Healthy volunteers between 21 and 65 years of age may be eligible for this study. Candidates are screened with a medical history and neurological examination.
Participants are divided into two groups. Group 1 has movement training sessions only and Group 2 has both movement training sessions and physiology sessions, as follows:
Movement training sessions
For 15 minutes every weekday, participants practice moving their wrist back and forth to make a cursor on the computer screen follow a target. Activity of the arm muscles is monitored with surface electrodes taped to the skin. The sessions continue until the participant can perform the movement well. Group 1 participants return to the clinic a week after the last session to perform the movement again to see if their skill level has changed. Each session lasts about 20 to 30 minutes.
Physiology sessions
In three separate sessions, the reflex for reciprocal inhibition is measured before and at several times during the movement task. This is done with nerve conduction studies. A probe placed on the skin delivers a low-intensity electrical stimulus. Wires taped to the skin record the nerve impulses. To measure reciprocal inhibition, several dozen stimuli are given to two nerves in combinations. Each session lasts 2 to 3 hours.
Objective:
Once a skilled movement is thoroughly learned, it can be performed relatively automatically. The motor cortex is active when learning a new motor skill, but becomes less activated once the skill has become over-learned. We hypothesize that learning a skilled movement is associated with more efficient use of subcortical motor circuits. Subcortical motor circuits can coordinate features of the intended movement such as the timing and patterns of activation of different muscles. The goal of this study is to determine whether learning a motor skill strengthens spinal interneuron circuits that facilitate the movement. Subjects will learn to perform a movement consisting of alternating wrist movements. The strength of reciprocal inhibition between antagonist muscles will be tested.
Study Population:
22 healthy adult volunteers
Design:
The study has two experiments. Both experiments use a within-subjects design. The purpose of the first experiment is to determine whether learning to accurately perform an alternating wrist flexion and extension movement task is associated with reduced co-contraction of wrist flexor and extensor muscles. Subjects will practice making accurate wrist flexions and extensions to keep a cursor on a target for fifteen-minute sessions every weekday until they are able to obtain 95% accuracy. Activity of the arm muscles will be monitored during the sessions with surface electrodes on the arm muscles. The first experiment will also determine the best training parameters for learning the task. In the second experiment, a second group of subjects will learn the task using the best training parameters. The strength of the reflex for reciprocal inhibition will be measured before, during and after training. Reciprocal inhibition will also be measured after the movement has become highly learned.
Outcome measures:
In the first experiment, the outcome will be the percent of movement time in which co-contraction occurs, as recorded from surface electrodes, while the subject learns to perform the movement to 95% accuracy. In the second experiment, the outcome measure is the strength of spinally mediated reciprocal inhibition, as measured using reflexes.
National Institute of Neurological Disorders and Stroke (NINDS) is the lead sponsor of 592 studies on the registry; 56 are open to participants now.
Of its 18 completed or terminated interventional studies of FDA-regulated products, 8 (44%) have results posted.
Counted across the registry records on this site, refreshed daily.
Healthy individuals between the ages of 21-65 years who are willing to participate in daily training sessions and physiological studies.
EXCLUSION CRITERIA:
Any history of peripheral nerve injury, cervical radiculopathy, arthritis, tendonitis, or surgery on the wrist.
This study is completed, as verified in Nov 2005. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
National Institute of Neurological Disorders and Stroke (NINDS)