Vibrotactile Stimulation in Lower Extremity Amputation Patients Using a Noninvasive Vibration Device: A Pilot Study

Background: 

Advances in surgery and prosthetic technology have improved limb control for amputation patients, but restoring sensory and proprioceptive feedback remains a challenge. This study evaluated the application of a vibrotactile sensory feedback device that aims at enhancing gait and reducing phantom limb pain (PLP) in lower extremity (LE) amputation patients who have undergone targeted muscle reinnervation (TMR). 

Methods: 

Four male LE amputation patients, 25-68 years of age, who underwent primary TMR, were fitted with a vibrotactile device using pressure sensors located on the sole of the prosthesis and a vibrating actuator on the proximal LE. This device incorporates vibrational stimuli when walking in a prosthesis for real-time sensory and proprioceptive feedback. Participants used the device alongside their regular prosthesis for 31 days. Pain, function, mental health, and satisfaction metrics were assessed using the visual analog scale, patient-reported outcomes measurement information system surveys, and various gait tests at baseline and follow-up. Baseline demographic, surgery, and comorbidity data were collected from chart review. 

Results: 

Three of 4 patients reported reduction in PLP and improvements in gait and device satisfaction. One young patient, who was highly active, showed limited improvement compared with the others. One patient experienced a reduction in anxiety and depression.

Conclusions: 

The vibrotactile feedback device demonstrated potential in improving PLP and gait among LE amputation patients who underwent primary TMR. Patient activity levels and psychological factors likely play important roles in the clinical effectiveness of the device. Future studies should focus on personalizing interventions based on patient profiles and exploring long-term benefits.