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Biomedical subjects

A H Seif-Naraghi

Publications and source records attributed to A H Seif-Naraghi.

2 recordsLinked to original sources

A novel method for locomotion training.

This article describes a novel therapeutic system for locomotion training and learning for patients with a wide range of neurological and musculoskeletal disorders. The technique embraces the notion that locomotion therapy should be goal oriented and task specific. The task specificity includes a partial weight-bearing device that permits the posture/equilibrium, movement, and weight-bearing components of gait function to operate concurrently, even in patients with serious deficits. In addition, it allows interaction with therapists and others to facilitate locomotion control, particularly during the early stages of gait therapy. Neurobiological bases for this technique and early clinical results are discussed, and two case studies of patients with traumatic brain injury (TBI) are presented. Although well-designed efficacy studies are needed, clearly this therapeutic approach to locomotor disorders among TBI patients meets the various criteria for recovery of gait function established in this article.

Adolescent↗

An analysis of the sources of musculoskeletal system impedance.

When antagonistic muscles co-contract, the impedance of musculoskeletal systems to applied loads is known to increase. In this paper a physiologically-based, higher-order, nonlinear antagonistic muscle-joint model is utilized to clarify the sources of impedance modulation during a variety of tasks, ranging from resisting transient loads to holding steady loads to making fast movements in unpredictable surroundings. It is shown that impedance modulation occurs automatically as a function of the specific operating ranges utilized during a given task by each of four different muscle-joint mechanical relations. The relative contribution of each relation depends on the type of task, with impedance during quasi-static conditions sensitive to muscle tension-length and sometimes joint parallel elastic properties and during dynamic tasks dominated by the series element and muscle force-velocity properties. Elimination of any of these causes a decrease in built-in biomechanical capabilities. These findings raise questions concerning past theories on stiffness-impedance modulation which appear to underestimate the role of inherent biomechanical properties.

Biomechanical Phenomena↗