Breathing trick and back zap boost walking after spinal injury

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Participants have been diagnosed with a spinal cord injury below level C2 * ASIA Impairment Scale Grade A-D * Participants are 18 years of age or older * Participants are at least 6 months post spinal cord injury * Participants with paraplegia or tetraplegia secondary to a single spinal cord injury * Participants are able to provide informed consent * Participants are not currently receiving regular physical therapy services Exclusion Criteria: * Individuals less than 18 years of age * Individuals less than 6 months post spinal cord injury * Individuals with ataxia * Individuals with multiple spinal cord injury history * Pregnancy or nursing * Pacemaker or anti-spasticity implantable pumps * Active pressure sores * Unhealed bone fractures * Peripheral neuropathies * Painful musculoskeletal dysfunction due to active injuries or infections * Severe contractures in the lower extremities * Active urinary tract infection * Clinically significant depression, psychiatric disorders, or ongoing drug abuse * Diagnosed with any of the following medical conditions: congestive heart failure, cardiac arrhythmias, uncontrolled hypertension, uncontrolled diabetes mellitus, chronic obstructive pulmonary disease, emphysema, severe asthma, previous myocardial infraction, or known carotid/intracerebral artery stenosis * Individuals with a tracheostomy or who utilize mechanical ventilation. * Individuals who are currently enrolled in another interventional research study or in therapy related to upper extremity function. * Participants will be excluded if they have had a botulinum toxin injection to lower extremity musculature within the last 3 months. Participants will need to refrain from lower extremity botulinum toxin injections for the duration of the study. If participants wean off antispasticity medications to successfully complete the responsiveness to AIH screening session, they will need to refrain from the medications for the duration of the study. * Documented sleep apnea. * Orthopedic injuries or surgeries that would impact an individual's ability to use the lower extremity. * Traumatic brain injury or other neurological conditions that would impact the study. * Blood hemoglobin levels less than 10g/dL. We will not include the following populations: * Adults unable to consent, unless accompanied by a legally authorized representative. * Individuals who are not yet adults (infants, children, teenagers) * Pregnant women * Prisoners