Operator-Driven Active Craniospinal Tensioning (ACT) Device for Non-ambulatory Application.

Active craniospinal tensioning (ACT) is an upright-posture axial spinal traction maneuver hypothesized to couple two mechanisms: dural pull-recoil, a cerebrospinal fluid (CSF) pressure-gradient effect shared with the supine technique pelvis-stabilized axial spinal traction (PSAST), and suboccipital venous occlusion-rebound, proposed to promote central nervous system (CNS) venous and lymphatic drainage, and as a distinct modality for cerebral venous preconditioning (CVPC). The CVPC mechanism depends on upright posture. In the upright position, cerebral venous return preferentially routes through the suboccipital venous plexus rather than the internal jugular veins, allowing the ACT strap to transiently occlude this outflow pathway during the hold and produce a hemodynamic rebound upon release. This CVPC-based rationale for choosing ACT over PSAST, along with the full biomechanical model, was developed in prior papers and is not re-derived here. In its originally described form, ACT is participant-driven: the participant voluntarily squats against a fixed overhead strap secured by a simple anchor, and the participant's own hands close the strap loop as a fail-safe. This report refers to that form, and the strap-and-anchor apparatus that delivers it, as active craniospinal tensioning, self-administered (ACT-SA). ACT-SA's delivered craniocervical junction (CCJ) tension depends on the participant fully relaxing into the maneuver. It categorically excludes non-ambulatory participants with advanced neurodegenerative disease, e.g., Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS), who cannot generate or safely control a voluntary squat, yet who may stand to benefit most from craniospinal tensioning and CVPC given their disease-associated glymphatic impairment. This report describes active craniospinal tensioning, operator-driven (ACT-OD), a device that reproduces ACT-SA's anchor geometry, target force range, and hold duration while substituting the source of tensioning force. Rather than gravity acting on a squatting participant's own body mass, tension is generated by a practitioner operating a pulley-and-lever mechanism against a stationary, seated participant, with the strap confined near the forehead by a polyvinyl chloride (PVC) pipe rather than closed by the participant's own hands. Because the participant does nothing and the seated default state carries no CCJ tension, the fail-safe ACT-SA requirement becomes unnecessary; disengagement, not engagement, is ACT-OD's default. Freed from managing the strap, the practitioner can devote full attention to the lever and to continuous observation of the participant's response, a substitution that matters because non-verbal or cognitively impaired participants cannot reliably self-report the presyncopal symptoms that serve as ACT-SA's real-time safety signal. The design is offered without patent restrictions for research and clinical replication. This report presents device design and mechanism only, with no clinical outcome or efficacy data.