Abstract: PD64-03
Sources of Funding: None

Introduction

Detailed studies from our institution have revealed sparing of motor function in trunk muscles below the level of injury and that use of an over ground robotic exoskeleton, which requires weight shifting to initiate stepping, can elicit core EMG activity below the level of injury. By extension, since PFM can often be co-contracted with core muscle activity, we hypothesized that PFM activity may also be demonstrable during exoskeleton-assisted gait training in motor complete SCI below the level of injury. Objective: characterize activation patterns of core and levator ani muscles during exoskeleton-assisted over ground walking vs treadmill walking with body-weight support in motor complete SCI vs able bodied controls.

Methods

Surface EMG were recorded from the rectus abdominis, external oblique, erector spinae (ES) and levator ani bilaterally. Foot switch signals linked heel strike to EMG activity (Biometrics Ltd, Newport, UK). Baseline, quiescent EMG activity were recorded for 20 sec. during sitting and support (by exoskeleton) standing. EMG activity during exoskeleton-assisted walking were recorded over ground with the Eksoâ„¢ and on the treadmill with Lokomatâ„¢. 40-60 steps were recorded during each walking trial, and walking speed was matched. Protocol was matched in controls. Bladder diaries and validated LUTS scores were completed.

Results

3 SCI (ASIA A levels T4, T4,C7; 2 male 1 female, age 33-39 yrs, 2-25 yrs since injury) participated. EMG from PFM, abdominal and ES showed heightened activity during over ground exoskeleton-assisted walking compared to treadmill in both complete SCI and controls. Robust rhythmic bursting was observed in PFM with exoskeleton walking, but not during supported standing or sitting. Fig MVC % exoskeleton (red) vs supported treadmill (black) vs quiet rest (grey).

Conclusions

EMG activity of PFM was demonstrable using over ground exoskeleton-assisted walking in motor complete SCI below the level of injury. Assisted gait training may reveal this preservation of function by imposing a higher demand on PFM compared to standing only. Potential activation of PFM with robotic gait training supports a novel direction in urologic management of SCI to challenge the levator ani; an important aspect in urinary tract function.

Funding

None