Wheelchair Axle Position Effect on the Propulsion Performance of Persons With C7 Tetraplegia: A Repeated-Measures Study.

Objectives: To assess the changes in speed, stroke frequency, acceleration, and shoulder range of motion (ROM) associated with different wheelchair axle positions in people with chronic C7 tetraplegia.

Methods: This repeated-measures study was conducted at the Chronic Spinal Cord Injury Unit, FLENI Escobar, Argentina. The speed, stroke frequency, acceleration, and shoulder ROM during wheelchair propulsion were measured in nine participants with C7 spinal cord injury (SCI) in four different axle positions (forward and up, forward and down, backward and down, backward and up).

Individual muscle force-energy rate is altered during crouch gait: A neuro-musculoskeletal evaluation.

Children with pathological movement patterns like crouch gait present with excessive knee and hip flexion during stance phase due to multiple factors. A good treatment requires that the primary factor is reduced or eliminated to optimise the relationship between muscle energy expenditure and muscle force production during walking. In this way, neuro-musculoskeletal simulations are reliable tools to evaluate how individual muscles contribute to gait.

Assessment of the energy-related cost function over a range of walking speeds.

Cost funtions are needed for calculation of muscle forces in musculoskeletal models. The behavior of the energy-related cost function, proposed by Praagman et al. (J Biomech 39(4):758-765, 2006.

Shoulder Functional Electrical Stimulation During Wheelchair Propulsion in Spinal Cord Injury Subjects.

Subjects with spinal cord injury (SCI) propel their wheelchairs by generating a different level of muscle activity given their multiple deficits in muscle strength. Exercise training programs seem to be effective in improving wheelchair propulsion capacity. Functional electrical stimulation (FES) therapy is a complementary tool for rehabilitation programs.

Estimation of muscle forces in gait using a simulation of the electromyographic activity and numerical optimization.

Clinical gait analysis provides great contributions to the understanding of gait patterns. However, a complete distribution of muscle forces throughout the gait cycle is a current challenge for many researchers. Two techniques are often used to estimate muscle forces: inverse dynamics with static optimization and computer muscle control that uses forward dynamics to minimize tracking.

Wheelchair axle position effect on start-up propulsion performance of persons with tetraplegia.

This repeated measures study assessed the changes in speed, acceleration, stroke frequency, and shoulder range of motion (ROM) associated with different wheelchair axle positions in people with chronic cervical (C) 6 tetraplegia. Our main hypothesis is that the up and forward axle position is the most conducive to wheelchair propulsion, increasing speed and acceleration with a lower stroke frequency. In a chronic spinal cord injury (SCI) unit, we measured the speed, acceleration, stroke frequency, and shoulder ROM in four different axle positions in eight subjects with C6 SCI.

Model to estimate hamstrings behavior in cerebral palsy patients: as a pre-surgical clinical diagnosis tool.

Crouch gait is the most common motion abnormality in children with cerebral palsy (CP). This paper presents a new biomechanical model based on a simple rescaling and adjustment to CP patients who develop crouch gait by subject-specific anthropometric data. The model estimates the length of hamstrings, as the distance between the origin and insertion of the muscle, and the velocity of shortening of hamstrings by the first derivative of the length with respect to time.