Effects of Deep Core Activation Method Using Wearable Cyborg HAL in a Supine Position for Ameliorating Defecatory Function: A Pilot Study

Fecal evacuation disorder and incontinence are prevalent problems among patients with spinal cord injury (SCI) which greatly affect their quality of life. A major cause of these issues is well associated with weakness in their deep core muscular activity. Current programs for amelioration in their deep core muscles are either difficult to apply to patients with SCI or highly invasive. We have previously proposed a minimally invasive method using the wearable cyborg Hybrid Assistive Limb (HAL) for use by patients with SCI. In our proposed method, long-term repetition of supine HAL-assisted hip flexion is thought to activate deep core muscles potentially ameliorating deep core muscular activity. Here, we conducted a pilot study to validate that our methodology is applicable to a patient with SCI. A 24 -year-old SCI patient with motor paralysis in his deep core muscles underwent four weeks of supine HAL-assisted hip flexion for thirty minutes, four times per week. To evaluate the effect of the intervention on the muscular activity, IAP measurement and sphincter electromyography were performed for seven days pre- / post-intervention. These assessments were repeated at a two-month follow-up after the intervention to verify the persistence of the effects. The increasing trends were observed in all periods of both IAP and in sphincter electromyogram. There was a significant increase in IAP and sphincter electromyogram between the pre-intervention and two-month follow-up ($\mathbf{p}<0.001$). These results demonstrate not only the applicability of our methodology to a patient with SCI but also the potential for ameliorating deep core muscular activity.