Transspinal Stimulation With and Without Blood Flow Restricted Exercise Via Telehealth in Persons With Tetraplegia

Change in hand functional activities

The grasp and release test is a standardized test of functional activities depending on hand function in persons with cSCI. Participants will be asked to lift and move a peg, block, can, 1 lb. dumbbell weight and fork from lateral to medial over a 60 cm distance and release at midline.

Change in maximum grip strength without TS

Using a standard hand-grip dynamometer, participants will be asked to squeeze the dynamometer with one hand at a time as strongly as possible for up to 3 seconds, to obtain a measure of the maximal voluntary force they can generate when closing their hand

Change in maximum grip strength with TS

Using a standard hand-grip dynamometer, participants will be asked to squeeze the dynamometer with one hand at a time as strongly as possible for up to 3 seconds, to obtain a measure of the maximal voluntary force they can generate when closing their hand with the addition of TS over the skin targeting the cervical spinal cord

Change in electrical activity activation with TS

During the assessment of maximal grip strength with TS, electromyography (EMG) will be used to measure the amount of neuromuscular electrical activation from the following muscle groups: wrist flexors, wrist extensors, elbow flexors, and elbow extensors.

Changes in capacity to perform functional activities

Functional activity will be measured using the Spinal Cord Injury-Functional Index Short Form (SCI-FI SF). The SCI-FI SF is a comprehensive measure of functional activity capacity for persons with SCI. It measures three subscales: Basic Mobility (9 items), Self-Care (9 items), and Fine Motor Function (8 items). Participants respond to item prompts using a Likert-type scale with anchors from 1 = "With much difficulty" to 4 = "Without any difficulty." Item scores for each subscale are summed and then converted to standardized T-scores, with higher scores reflecting greater functional capacity. We will use the tetraplegia-specific versions of the Self-Care and Fine Motor Function subscales.

Change in vital capacity

Forced vital capacity is an evaluation of how much air a person can forcefully exhale after a maximal inspiratory effort. Tests are conducted using a digital spirometer or respiratory monitor. Participants will be asked to seal their lips around a disposable mouthpiece connected to the respiratory monitor via an anti-viral/anti-bacterial filter, then take a maximal inhalation immediately followed by a forceful exhalation which participants will be encouraged to maintain for as long as possible.

Change in ventilatory muscle strength

Maximal inspiratory pressure and maximal expiratory pressure using a digital respiratory pressure meter are measures of ventilatory muscle strength. Participants will be asked to exhale fully, then seal their lips around a disposable mouthpiece and inhale as strongly as possible against an occlusion. They will be asked to inhale maximally and then exhale through a disposable mouthpiece against an occlusion.

Change in heart rate variability

Tilt table test for heart rate variability will be used to assess changes in heart rate variability.