Brownian processes in human motor control support descending neural velocity commands.

The motor neuroscience literature suggests that the central nervous system may encode some motor commands in terms of velocity. In this work, we tackle the question: what consequences would velocity commands produce at the behavioral level? Considering the ubiquitous presence of noise in the neuromusculoskeletal system, we predict that velocity commands affected by stationary noise would produce "random walks", also known as Brownian processes, in position. Brownian motions are distinctively characterized by a linearly growing variance and a power spectral density that declines in inverse proportion to frequency.

Complications in Total Ankle Replacement.

The debate between ankle arthrodesis and total ankle replacement for patients with end-stage arthritis of the ankle joint is an ongoing topic in orthopedic surgery. Ankle arthrodesis, or fusion, has been the traditional treatment for ankle arthritis. It involves fusing the bones of the ankle joint together, eliminating the joint and creating a solid bony union.

Does anxiety influence outcome measurements in ankle replacement patients?

Background: Total ankle arthroplasty (TAA) is increasingly used to treat end-stage ankle arthritis to restore ankle functional outcomes and alleviate pain. This treatment outcome may be influenced by pre-morbid patient anxiety.

Methods: Twenty-five Infinity TAA implants were prospectively followed post-operatively with a mean follow-up time of 34.

Dynamic primitives in constrained action: systematic changes in the zero-force trajectory.

Humans substantially outperform robotic systems in tasks that require physical interaction, despite seemingly inferior muscle bandwidth and slow neural information transmission. The control strategies that enable this performance remain poorly understood. To bridge that gap, this study examined kinematically constrained motion as an intermediate step between the widely studied unconstrained motions and sparsely studied physical interactions.

Development and validation of a clinical tool to semi-automatic measure three-dimensional TAR alignment on two-dimensional radiographs.

Background: Malalignment is often postulated as an important reason for the high failure rate of total ankle replacements (TARs). The correlation between TAR malalignment and clinical outcome, however, is not fully understood. Improving and expanding radiographic TAR alignment measurements in the clinic might lead to a better insight into the correlation between malalignment and the clinical outcome.