Setting and Participants
The study was performed in the Outpatient Physical Therapy Department at WJBDVAMC. Veterans with DPN who met the inclusion/exclusion criteria were enrolled. Inclusion criteria specified that the participant must be referred by a qualified health care provider for the treatment of DPN, be able to read and write in English, have consistent transportation to and from the study location, and be able to apply MIRE therapy as directed at home.
Exclusion criteria were subjects for whom MIRE or exercise were contraindicated. Subjects were excluded if they had medical conditions that suggested a possible decline in health status in the next 6 months. Such conditions included a current regimen of chemotherapy, radiation therapy, or dialysis; recent lower extremity amputation without prosthesis; documented active alcohol and/or drug misuse; advanced chronic obstructive pulmonary disease as defined as dyspnea at rest at least once per day; unstable angina; hemiplegia or other lower extremity paralysis; and a history of central nervous system or peripheral nervous system demyelinating disorders. Additional exclusion criteria included hospitalization in the past 60 days, use of any apparatus for continuous or patient-controlled analgesia; history of chronic low back pain with documented radiculopathy; and any change in pertinent medications in the past 60 days, including pain medications, insulin, metformin, and anti-inflammatories.
Interventions
Subjects participated in a combined physical therapy approach using MIRE and a standardized balance program. Patients received treatment in the outpatient clinic 3 times each week for 4 weeks. The treatment then continued at the same frequency at home until the scheduled 6-month follow-up visit. Clinic and home treatments included application of MIRE to bilateral lower extremities and feet for 30 minutes each as well as performance of a therapeutic exercise program for balance.
In the clinic, 2 pads from the MIRE device (Anodyne Therapy, LLC, Tampa, FL) were placed along the medial and lateral aspect of each lower leg, and an additional 2 pads were placed in a T formation on the plantar surface of each foot, per the manufacturer’s recommendations. The T formation consisted of the first pad placed horizontally across the metatarsal heads and the second placed vertically down the length of the foot. Each pad was protected by plastic wrap to ensure proper hygiene and secured. The intensity of clinic treatments was set at 7 bars, which minimized the risk of burns. Home treatments were similar to those in the clinic, except that each leg had to be treated individually instead of simultaneously and home MIRE units are preset and only function at an intensity that is equivalent to around 7 bars on the clinical unit.
The standardized balance program consisted of a progression of the following exercises: ankle alphabet/ankle range of motion, standing lateral weight shifts, bilateral heel raises, bilateral toe raises, unilateral heel raises, unilateral toe raises, partial wall squats, and single leg stance. Each participant performed these exercises 3 times per week in the clinic and then 3 times per week at home following the 12th visit.