Spinal Excitation to Enhance Mobility
Condition: Aging
Intervention: tsDCS Dosage (A); tsDCS Dosage (B); textured shoe insoles
Intervention description: mild electrical stimulation delivered to lumbosacral spinal cord; mild electrical stimulation delivered to lumbosacral spinal cord; textured shoe insoles
Phase: Phase 1
Study type: Interventional
Primary purpose: Other
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants will be randomized to one of four different parallel groups
Masking: Single (Participant)
Masking description: Participants will be masked to the dosage of transcutaneous spinal direct current stimulation (tsDCS)
Enrollment: 23.0
Sex: All
Minimum age: 65 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: aging; walking; spinal cord; electrical stimulation

Summary:

      Older adults with compromised walking ability have higher rates of morbidity and mortality,
      more hospitalizations, poorer quality of life, and are less likely to remain independent in
      the community. It is known that age-related changes in brain and peripheral nerves contribute
      to loss of walking ability. However, there is a lack of research into how the aging spinal
      cord affects walking. In older adults, the spinal cord is less excitable, conducts signals
      more slowly, and is subject to neural noise. Intervening on age-related impairment of the
      spinal cord to improve walking ability is a very promising but untapped area of research.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Preferred 10m walking speed < 1.0 m/s

          -  Intact tactile sensation based on two-point discrimination

          -  Willingness to be randomized to either intervention and to participate in all aspects
             of study assessment and intervention

        Exclusion Criteria:

          -  Diagnosed neurological disorder or injury of the central nervous system, or
             observation of symptoms consistent with such a condition

               -  spinal cord injury

               -  Alzheimer's

               -  Parkinson's

               -  stroke, etc.

          -  Contraindications to non-invasive spinal stimulation including any prior spinal
             surgical procedure

          -  Chronic lower back pain

          -  Obesity, defined as Body Mass Index exceeding 30.

               -  This is due to the potential influence of body fat on the amplitude of electrical
                  current flow to the spinal cord.

          -  Use of medications affecting the central nervous system including, but not limited to:

               -  benzodiazepines

               -  anti-cholinergic medication and GABAergic medication

          -  Severe arthritis, such as awaiting joint replacement

          -  Current cardiovascular, lung or renal disease

          -  Diabetes

          -  Terminal illness

          -  Myocardial infarction or major heart surgery in the previous year

          -  Cancer treatment in the past year, except for nonmelanoma skin cancers and cancers
             having an excellent prognosis

               -  early stage breast or prostate cancer

          -  Current diagnosis of schizophrenia, other psychotic disorders, or bipolar disorder

          -  Difficulty communicating with study personnel

               -  including people who cannot speak English

          -  Uncontrolled hypertension at rest (systolic > 180 mmHg and/or diastolic > 100 mmHg)

          -  Bone fracture or joint replacement in the previous six months

          -  Current participation in physical therapy for lower extremity function or
             cardiopulmonary rehabilitation

          -  Current enrollment in any clinical trial

          -  Planning to relocate out of the area during the study period

          -  Clinical judgment of investigative team