Intermittent Hypoxia and Locomotor Training Enhances Dynamic but Not Standing Balance in Patients With Incomplete Spinal Cord Injury

Objective: To test the effect of combined intermittent hypoxia (IH) and body weight supported treadmill training (BWSTT) on standing and dynamic balance in persons with incomplete spinal cord injury (iSCI). Design: Randomized, triple-blind, placebo-controlled study. Setting: Rehabilitation medical centers. Participants: Study participants (N=35) with chronic iSCI with American Spinal Injury Association grades C and D (> 1y postinjury) were randomly assigned to either IH plus BWSTT (n=18) or continued normoxia (placebo) plus BWSTT protocol (n=17). Interventions: Participants received either IH (alternating 1.5min 9% inspired O-2 with 1.5min 21% inspired O-2, 15 cycles per day) or continued normoxia (21% 02) combined with 45 minutes of BWSTT for 5 consecutive days, followed by 3 times per week IH or normoxia plus BWSTT, for 3 additional weeks. Main Outcome Measures: Standing balance (normalized jerk and root-mean-square [RMS]) and dynamic balance (turning duration, cadence in a turn, and turn-to-sit duration) were assessed before and after IH and normoxia protocol by means of instrumented sway and instrumented timed Up and Go test. Results: There was no significant difference in standing balance between interventions for both normalized jerk and RMS instrumented sway components (both P >.05). There was a significantly faster cadence (P <.001), turning duration (P <.001), and turn-to-sit duration (P=.001) in subjects receiving IH plus BWSTT, compared with placebo. Conclusions: A 4-week protocol of IH combined with locomotor training improves dynamic, but not standing, balance in persons with iSCI. (C) 2016 by the American Congress of Rehabilitation Medicine