publications

2022

1. Alpha-Band Activity in Parietofrontal Cortex Predicts Future Availability of Vibrotactile Feedback in Prosthesis Use

   Johnson, John T., de Mari, Daniele, Doherty, Harper, Hammond, Frank L., and Wheaton, Lewis A.

   Experimental Brain Research Mar 2022

   Abs

   Prosthesis disuse and abandonment is an ongoing issue in upper-limb amputation. In addition to lost structural and motor function, amputation also results in decreased task-specific sensory information. One proposed remedy is augmenting somatosensory information using vibrotactile feedback to provide tactile feedback of grasping objects. While the role of frontal and parietal areas in motor tasks is well established, the neural and kinematic effects of this augmented vibrotactile feedback remain in question. In this study, we sought to understand the neurobehavioral effects of providing augmented feedback during a reach-grasp-transport task. Ten persons with sound limbs performed a motor task while wearing a prosthesis simulator with and without vibrotactile feedback. We hypothesized that providing vibrotactile feedback during prosthesis use would increase activity in frontal and parietal areas and improve grasp-related behavior. Results show that anticipation of upcoming vibrotactile feedback may be encoded in motor and parietal areas during the reach-to-grasp phase of the task. While grasp aperture is unaffected by vibrotactile feedback, the availability of vibrotactile feedback does lead to a reduction in velocity during object transport. These results help shed light on how engineered feedback is utilized by prostheses users and provide methodologies for further assessment in advanced prosthetics research.

2. Partial-Hand Prosthesis Users Show Improved Reach-to-Grasp Behaviour Compared to Transradial Prosthesis Users with Increased Task Complexity

   Alterman, Bennett L., Keeton, Emily, Ali, Saif, Binkley, Katrina, Hendrix, William, Lee, Perry J., Wang, Shuo, Kling, James, Johnson, John T., and Wheaton, Lewis A.

   Journal of Motor Behavior Apr 2022

   Abs

   Approaches to improve outcomes after upperextremity amputation remain poorly understood. Examining prosthesis-use at different levels of loss elucidates motor control challenges. Non-amputated participants completed simple and complex reach-to-grasp actions using a body-powered transradial or partial-hand prosthesis simulator. We hypothesised that increased task complexity and participants using a partial-hand device would show greater functional adaptation compared to participants using a transradial device. Partialhand users demonstrated variable grasp postures and higher reach peak velocities in the complex, but not simple, task. All groups showed decreases in movement duration in the complex task, but only partial-hand users improved in the simple task. These behavioural changes suggest how device level and task may influence prosthesis-use, with relevance to amputation rehabilitation.

2021

1. Neurorehabilitation in Adults With Traumatic Upper Extremity Amputation: A Scoping Review

   Rydland, Jake, Spiegel, Stephanie, Wolfe, Olivia, Alterman, Bennett, Johnson, John T, and Wheaton, Lewis A

   Neurorehabilitation and Neural Repair Dec 2021

   Abs

   Background Most of the current literature around amputation focuses on lower extremity amputation or engineering aspects of prosthetic devices. There is a need to more clearly understand neurobehavioral mechanisms related to upper extremity amputation and how such mechanisms might influence recovery and utilization of prostheses. Objective This scoping review aims to identify and summarize the current literature on adult traumatic upper limb amputation in regard to recovery and functional outcomes and how neuroplasticity might influence these findings. Methods We identified appropriate articles using Academic Search Complete EBSCO, OVID Medline, and Cochrane databases. The resulting articles were then exported, screened, and reviewed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR) guidelines. Results Eleven (11) studies met the study criteria. Of these studies, 7 focused on sensory involvement, 3 focused on neuroplastic changes post-amputation related to functional impact, and 1 study focused on motor control and learning post-amputation. Overall, these studies revealed an incomplete understanding of the neural mechanisms involved in motor rehabilitation in the central and peripheral nervous systems, while also demonstrating the value of an individualized approach to neurorehabilitation in upper limb loss. Conclusions There is a gap in our understanding of the role of neurorehabilitation following amputation. Overall, focused rehabilitation parameters, demographic information, and clarity around central and peripheral neural mechanisms are needed in future research to address neurobehavioral mechanisms to promote functional recovery following traumatic upper extremity amputation.