Activating Spinal Circuits to Improve Walking, Balance, Strength, and Reduce Spasticity
Study Details
Study Description
Brief Summary
For many people with spinal cord injury (SCI), the goal of walking is a high priority. There are many approaches available to restore walking function after SCI; however, these approaches often involve extensive rehabilitation training and access to facilities, qualified staff, and advanced technology that make practicing walking at home difficult. For this reason, developing training approaches that could be easily performed in the home would be of great value. In addition, non-invasive spinal stimulation has the potential to increase the effectiveness of communication between the brain and spinal cord. Combining motor skill training with spinal stimulation may further enhance the restoration of function in persons with SCI. Therefore, the purpose of this study is to determine if moderate-intensity, motor skill training can improve walking-related outcomes among persons with SCI and to determine if the addition of non-invasive spinal stimulation will result in greater improvements in function compared to training alone.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Detailed Description
Participants in this study will complete a two week "wash-in" period where they will participate in strength and conditioning activities as part of an existing outpatient clinical program. Participants will complete baseline testing prior to the 2-week wash-in conditioning period, post wash-in testing following the wash-in period (prior to beginning the intervention), 2-week intervention period (6 motor training sessions), and follow-up testing within one week of the final intervention. Additionally, there will be two questionnaires completed during initial testing and following completion of the intervention. During training sessions, participants will perform a series of 6 motor skill exercises designed to challenge balance, lower extremity coordination, agility, and speed. In addition, a subset of tests will be performed before and after training to monitor within-day change in outcomes. Participants will be randomized and allocated to one of three groups: (1) motor skill training (MST) only, (2) MST + transcutaneous spinal stimulation (TSS), or (3) lower-extremity cyclic aerobic exercise + TSS. The MST+TSS group will receive spinal stimulation concurrently with training, while the MST only group will receive a sham stimulation protocol. Each participant will complete the 6-exercise MST circuit 4 times. MST sessions will take approximately 30 minutes to complete and will be preceded and followed by balance and walking function assessments in order to examine effects of intervention over time.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: MST + TSS Individuals will participate in 6 sessions of lower extremity motor skill training (MST) combined with transcutaneous spinal stimulation (TSS) delivered at an intensity high enough to induce paresthesia in the lower extremities (or as high as tolerable without paresthesia) to the space between vertebra T11/12. This occurs over a 2 week span. |
Behavioral: Motor Skill Training
Motor skill training (MST) will consist of 5 activities performed while standing to promote upright control and one activity performed while seated (alternating toe-tapping) to provide opportunity for active recovery. Participants will perform each skill exercise for one minute each, until 4 cycles of the circuit have been completed (approximately 30 minutes total). Motor training activities will be performed at an intensity of 40-59% of heart rate reserve (HRR). During MST, participants will wear a chest-worn heart rate monitor to ensure that the optimal HRR range is achieved. HRR will be calculated from resting and peak heart rate measures obtained during baseline testing via administration of a graded-exercise test.
Device: Transcutaneous Spinal Stimulation
The TSS electrode placement is based on previous literature that produced improvements in walking function. TSS is designed to activate the 1a afferent fibers exiting the spinal cord from the posterior root, resulting in modulation of the threshold of activation for the nervous system. The cathode will be placed in the space between vertebra T11/12 and the anode will consist of 2 electrodes acting as one, each placed on a respective ASIS. The stimulus intensity will be set at a level that produces paresthesia in the lower extremities or at the highest tolerable intensity. The TSS device is lightweight, and can be worn in a backpack during the MST activities. As reported previously, participants in the MST-only group will receive sham TSS to maintain analogous study procedures.
Other Names:
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| Sham Comparator: MST + Sham TSS Individuals will participate in 6 sessions of lower extremity motor skill training (MST) while receiving sham transcutaneous spinal stimulation (TSS) over a 2 week span. |
Behavioral: Motor Skill Training
Motor skill training (MST) will consist of 5 activities performed while standing to promote upright control and one activity performed while seated (alternating toe-tapping) to provide opportunity for active recovery. Participants will perform each skill exercise for one minute each, until 4 cycles of the circuit have been completed (approximately 30 minutes total). Motor training activities will be performed at an intensity of 40-59% of heart rate reserve (HRR). During MST, participants will wear a chest-worn heart rate monitor to ensure that the optimal HRR range is achieved. HRR will be calculated from resting and peak heart rate measures obtained during baseline testing via administration of a graded-exercise test.
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| Active Comparator: CAX + TSS Individuals will participate in 6 sessions of cyclic aerobic exercise (CAX) while receiving transcutaneous spinal stimulation (TSS) at an intensity high enough to induce paresthesia in the lower extremities (or as high as tolerable without paresthesia) to the space between vertebra T11/12. This occurs over a 2 week span. |
Device: Transcutaneous Spinal Stimulation
The TSS electrode placement is based on previous literature that produced improvements in walking function. TSS is designed to activate the 1a afferent fibers exiting the spinal cord from the posterior root, resulting in modulation of the threshold of activation for the nervous system. The cathode will be placed in the space between vertebra T11/12 and the anode will consist of 2 electrodes acting as one, each placed on a respective ASIS. The stimulus intensity will be set at a level that produces paresthesia in the lower extremities or at the highest tolerable intensity. The TSS device is lightweight, and can be worn in a backpack during the MST activities. As reported previously, participants in the MST-only group will receive sham TSS to maintain analogous study procedures.
Other Names:
Behavioral: Cyclic Aerobic Exercise
Participants will complete 30 minutes of seated elliptical exercise and will be ask to maintain a constant step rate for the duration of the intervention. During CAX, participants will wear a chest-worn heart rate monitor to ensure that a HRR range of 40-59% is maintained. Resistance level will be adjusted to ensure the optimal target heart rate is achieved.
Other Names:
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Outcome Measures
Primary Outcome Measures
- Change in 10 Meter Walk Test [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Walking speed (as determined by the 10 Meter Walk Test [10MWT]) is the primary outcome measure for assessing walking function. Walking speed is a widely used clinical measure of walking function and allows for comparison of our findings to other published studies. Participants will complete 3 10MWT trials at each time point, separated by 2 minutes of seated rest. The average walking speed of 3 walks will be calculated and used in the analyses. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
Secondary Outcome Measures
- Change of Spatiotemporal Gait Characteristic (Cadence) [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Gait quality will be assessed from spatiotemporal gait characteristics (cadence [strides/min], stride length [cm] and step length [cm] of the weaker and stronger limbs) collected via instrumented walkway (GAITRite, CIR Systems Inc., NJ, USA) as participants completed three, 10MWT trials at each time point. Cadence for each walk trial will be computed using the GAITRite system, and the average cadence across three walks will be used in the analyses. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
- Change of Spatiotemporal Gait Characteristic (Stride Length - Weaker Limb) [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Gait quality will be quantified by spatiotemporal gait characteristics (cadence [strides/min], stride length [cm] and step length [cm] of the weaker and stronger limbs) collected via instrumented walkway (GAITRite, CIR Systems Inc., NJ, USA) as participants complete three, 10-Meter Walk Test trials at each time point. Average stride length of the weaker limb for each walk trial will be computed from data obtained from the GAITRite system, and the average stride length across three walks will be used in the analyses. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27).
- Change of Spatiotemporal Gait Characteristic (Stride Length - Stronger Limb) [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Gait quality will be quantified by spatiotemporal gait characteristics (cadence [strides/min], stride length [cm] and step length [cm] of the weaker and stronger limbs) collected via instrumented walkway (GAITRite, CIR Systems Inc., NJ, USA) as participants complete three, 10-Meter Walk Test trials at each time point. Average stride length of the stronger limb for each walk trial will be computed from data obtained from the GAITRite system, and the average stride length across three walks will be used in the analyses. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27).
- Change of Spatiotemporal Gait Characteristic (Step Length Symmetry - Symmetry Index) [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Step length [cm] of the weaker and stronger limbs will be collected via instrumented walkway (GAITRite, CIR Systems Inc., NJ, USA) as participants completed 3, 10-Meter Walk Test trials at each time point. Average step length of each lower limb for each walk trial will be computed from data obtained from the GAITRite system. The average step length will be used to calculate the step symmetry index (SI) using the following formula: SI = ((SLs - SLw)/0.5(SLs + SLw)) x 100; where SLs = stronger limb stride length and SLw = weaker limb stride length. Final values will be reported as the absolute % of the ratio difference in step length between the stronger and weaker limbs. A SI value of 0% indicates perfect interlimb step symmetry. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27).
- Change of Berg Balance Scale [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Balance will be measured using the Berg Balance Scale (BBS), which has been found to be valid for use in persons with SCI. The BBS total score will be calculated for each participant at each time point, and the median score for each group will be calculated. The total range of scores for the BBS equals 0-56, with higher scores from baseline indicating greater balance performance and lower scores from baseline indicating worsened balance performance. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27).
- Change of Falls Efficacy Scale-International Version (FES-I) [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27), Evaluation 4 (Day 30)]
The fear of falling may be a major concern for persons with mobility impairments and may limit one's confidence or ability to perform activities of daily living. Fear of falling may also limit an individual's performance of specific overground motor tasks irrespective of functional ability to perform that task. Therefore, the fear of falling is an important factor to consider relative to the mobility interventions employed in the present study. The FES-I total score will be calculated for each participant at each time point, and the median for each group was recorded. The total range of scores possible for the FES-I is equal to 16-64, with lower total scores indicating decreased fear of falling. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13), at follow-up after intervention on Evaluation 3 (Day 27), and at Evaluation 4 (subjective follow-up 3 days after evaluation; Day 30).
- Change of Spinal Cord Assessment Tool for Spastic Reflexes [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
The Spinal Cord Assessment Tool for Spastic Reflexes (SCATS) will be used to assess the impact of motor skill training + sham stimulation and motor training + tDCS on spasticity. SCATS is well correlated with electrophysiological measures of spasticity and is better correlated with self-reported measures of spasm frequency than the Ashworth test. Total SCATS scores for each limb will be summed and median values will be obtained for each group. The total range of scores possible for the SCATS is 0-18, with a total score of 0 indicating no lower limb spasticity and higher total scores indicating greater spasticity severity. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
- Change of Modified 5-Times Sit-to-Stand [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
The modified 5-times sit-to-stand test will be used as a measure of functional lower extremity strength. In this test, the participant will be seated on a mat table with height adjusted to 80% of lower extremity length. The time required to complete 5 repetitions of standing up and sitting down (without using the upper extremities for assistance) will be recorded. The average time to complete the test will be calculated at each time point for each group. Lower sit-to-stand times indicate greater functional lower extremity strength. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
- Change of 2 Minute Walk Test [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Functional walking capacity will be measured based on 2-minute walk test distance. The use of the 2-minute rather than the 6-minute walk test allowed us to include individuals whose impairments result in inability to walk for 6 minutes. Total distance walked in 2-minutes will be recorded for each participant at each time point, and the average distance will be calculated for each group. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
- Change of Maximal Isometric Quadriceps Strength [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Knee extensor (quadriceps) strength will be measured with the subject seated and and utilizing the BTE PrimusRS. Maximum knee extensor force will be analyzed based on the maximum force produced over three attempts. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.t-intervention.
- Change of Maximal Isometric Dorsiflexor Strength [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Ankle dorsiflexion (tibialis anterior) strength will be measured with the subject seated and and utilizing the BTE PrimusRS. An ankle dorsiflexion test has been selected based on evidence indicating that the tibialis anterior is under the greatest corticospinal control. Maximum dorsiflexion force will be calculated based on the highest force measured over three attempts. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
- Change of Rate of Torque Production [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27)]
Rate of torque production will be measured with the subject seated and and utilizing the BTE PrimusRS. Maximum rate of torque production will be calculated based on the highest rate measured over three attempts. Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13) and at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention.
- Change of Spinal Cord Injury Spasticity Evaluation Tool (SCI-SET) [Evaluation 1(Day 1), Evaluation 2 (Day 13), Evaluation 3 (Day 27), Evaluation 4 (Day 30)]
The Spinal Cord Injury Spasticity Evaluation Tool (SCI-SET) is a subjective measure used to assess the effects of spasticity on daily life in people with SCI. The SCI-SET requires participants to recall their past 7 days when rating the impact of spasticity. The scale uses a range of -3 (extremely problematic) to +3 (extremely helpful). Data reported will be obtained prior to wash-in at baseline at Evaluation 1 (Day 1), post wash-in/pre-intervention will occur at Evaluation 2 (Day 13), at follow-up after intervention on Evaluation 3 (Day 27), 24-hours post-intervention. and at Evaluation 4 (subjective follow-up 3 days after evaluation; Day 30).
Eligibility Criteria
Criteria
Inclusion Criteria:
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Have a spinal cord injury (neurological level T12 or above)
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Sub-acute to Chronic SCI (3 months or greater)
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Neurological impairment classification C or D
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Able to stand for at least 5 minutes (with or without an assistive device)
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Able to move each leg independently for at least 3 steps
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Able to rise from sit to stand with no more than moderate assistance from one person
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Ability and willingness to consent and authorize use of personal health information
Exclusion Criteria:
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Progressive spinal lesions including degenerative, or progressive vascular disorders of the spine and/or spinal cord
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Injuries below the neurological spinal level of T12
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Pregnancy, or if you have reason to believe you are or may become pregnant due to unknown risks to the fetus associated with TSS
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History of uncontrolled cardiovascular condition
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Altered cognitive status
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Presence of orthopedic conditions that would adversely affect participation in exercise
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History of seizures
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Inability and unwillingness to consent and authorize use of personal health information
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Shepherd Center | Atlanta | Georgia | United States | 30309 |
Sponsors and Collaborators
- Shepherd Center, Atlanta GA
- National Institute on Disability, Independent Living, and Rehabilitation Research
Investigators
- Principal Investigator: Edelle C Field-Fote, PT, PhD, Shepherd Center, Atlanta GA
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 1842303