The effects of combined trunk and gluteal neuromuscular electrical stimulation on posture and tissue health in spinal cord injury

Abstract

Objective: To investigate whether combined trunk and gluteal neuromuscular electrical stimulation (NMES) alters seated posture and improves pelvic tissue health in persons with a spinal cord injury.

Design: Intervention study; case series.

Setting: Research laboratory, medical center.

Participants: Seven persons with spinal cord injury recruited from a group of experienced implanted lower extremity NMES system users.

Intervention: Combined trunk and gluteal NMES in the sitting position. Five minutes of preintervention sitting was assessed, followed by 5 minutes of NMES application, and then 5 minutes of postintervention.

Main outcome measures: Pelvic tissue health was evaluated by concurrently measuring transcutaneous oxygen tension (TcPO2) bilaterally over the ischia and the seating interface pressure (IP). TcPO2 data were binned into low (<10 mm Hg), medium (10-30 mm Hg), and high (>30 mm Hg) ranges, and the percentage time that TcPO2 was in each range was calculated. Ischial and sacral regions of interest were defined and the maximum region of interest and mean IP were determined, together with the maximum IP gradient for the entire contact area. Initial seating postures varied; 4 persons were initially sacral sitters. Tissue health responses to NMES were reviewed for sacral and nonsacral sitters.

Results: For sacral sitters, the sacral region IP and the maximum IP gradient tended to decrease during NMES and increased again after the intervention. Mean ischial TcPO2 increased during NMES and remained elevated after the intervention, increasing high TcPO2 percentage time for 50% of the sacral sitters both during and after the intervention. Nonsacral sitters showed few changes in tissue health as the result of the application of NMES.

Conclusions: Trunk and gluteal stimulation acutely corrects anterior/posterior IP distribution, improving regional tissue health for sacral sitters. This correction requires constant application of NMES. The potential for positive changes in tissue health would be maximized by regular NMES use incorporating weight shifting.

Trial registration: ClinicalTrials.gov NCT01474148.