JournalArticle

B Blaser, S Burgstahler, KM Steele, (2015) “Including universal design in engineering courses to attract diverse students.” Proceedings of the American Society for Engineering Education

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Paper at American Society of Engineering Education

Brianna Blaser and Kat Steele presented their paper, “Including universal design in engineering courses to attract diverse students” at the American Society for Engineering Education annual conference in Seattle, WA on June 17, 2015. This paper reported the results of a survey to current students with disabilities about their experiences in engineering classes and how accessibility and universal design may be incorporated into the engineering curriculum.

Abstract:

Research has shown that members of some groups, including women and people with disabilities, are particularly interested in how their fields of study, such as engineering, can improve the world around them. Teaching students about universal design (UD) and how it benefits individuals with disabilities has the potential to attract these students to engineering and encourage them to create products and environments that are accessible to and usable by individuals with a broad range of characteristics. In this paper, we present findings from an online discussion and site visits to engineering labs with students with disabilities. Based on these findings, we identify opportunities for including disability and UD topics in engineering curricula. Capstone or cornerstone engineering design classes are a natural fit for incorporating these concepts, but other engineering course can be enhanced with disability and UD content as well. We also present suggestions for applying UD to instruction in order to ensure that engineering courses are accessible to the widest audience possible. This investigation provides a foundation for using UD to broaden participation in engineering and training engineers who can design products and environments that address the diverse needs of society.

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KM Steele, MC Tresch, EJ Perreault (2015) “Consequences of biomechanically constrained tasks in the design and interpretation of synergy analyses.” Journal of Neurophysiology

Dr. Steele JournalArticle, MotorControl ,
Synergy similarity is reduced with musculoskeletal constraints.

Journal article in Journal of Neurophysiology: 

Consequences of biomechanically constrained tasks in the design and interpretation of synergy analyses

Matrix factorization algorithms are commonly used to analyze muscle activity and provide insight into neuromuscular control. These algorithms identify low-dimensional subspaces, commonly referred to as synergies, which can describe variation in muscle activity during a task. Synergies are often interpreted as reflecting underlying neural control; however, it is unclear how these analyses are influenced by biomechanical and task constraints, which can also lead to low-dimensional patterns of muscle activation. The aim of this study was to evaluate whether commonly used algorithms and experimental methods can accurately identify synergy-based control strategies. This was accomplished by evaluating synergies from five common matrix factorization algorithms using muscle activations calculated from 1) a biomechanically constrained task using a musculoskeletal model and 2) without task constraints using random synergy activations. Algorithm performance was assessed by calculating the similarity between estimated synergies and those imposed during the simulations; similarities ranged from 0 (random chance) to 1 (perfect similarity). Although some of the algorithms could accurately estimate specified synergies without biomechanical or task constraints (similarity >0.7), with these constraints the similarity of estimated synergies decreased significantly (0.3-0.4). The ability of these algorithms to accurately identify synergies was negatively impacted by correlation of synergy activations, which are increased when substantial biomechanical or task constraints are present. Increased variability in synergy activations, which can be captured using robust experimental paradigms that include natural variability in motor activation patterns, improved identification accuracy but did not completely overcome effects of biomechanical and task constraints. These results demonstrate that a biomechanically constrained task can reduce the accuracy of estimated synergies and highlight the importance of using experimental protocols with physiological variability to improve synergy analyses. PDF

H Choi, K Bjornson, S Fatone, KM Steele (2015) “Using musculoskeletal modeling to evaluate the effect of ankle foot orthosis tuning on musculotendon dynamics: a case study.” Disability and Rehabilitation

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H Choi, K Bjornson, S Fatone, KM Steele (2015) “Using musculoskeletal modeling to evaluate the effect of ankle foot orthosis tuning on musculotendon dynamics: a case study.” Disability and Rehabilitation

Journal article accepted in Disability and Rehabilitation:

Using musculoskeletal modeling to evaluate the effect of ankle foot orthosis tuning on musculotendon dynamics: a case study.

This case study examines the influence of an ankle foot orthosis footwear combination (AFO-FC) on musculotendon lengths and gait kinematics and kinetics after right thrombotic stroke resulting in left hemiplegia. Methods: Gait analysis was performed over three visits where the subject walked with an AFO-FC with two shank-to-vertical angle (SVA) alignments, a posterior leaf spring AFO (PLS AFO), and shoes alone. Biomechanical and musculoskeletal modeling was used to evaluate musculotendon lengths, kinematics, and kinetics for each condition. Results: The AFO-FC improved walking speed and non-paretic kinematics compared to the PLS AFO and shoes alone. The operating length of the paretic gastrocnemius decreased with the AFO-FC improving knee kinematics in swing, but not stance. As the SVA of the AFO-FC was reduced from 15° to 12°, internal ankle plantar flexor moment increased. Conclusions: Musculoskeletal modeling demonstrated that the AFO-FC altered gastrocnemius operating length during post-stroke hemiplegic gait. Using these tools to evaluate muscle operating lengths can provide insight into underlying mechanisms that may improve gait and guide future AFO-FC design. PDF

KM Steele and S Lee (2014) “Using dynamic musculoskeletal simulation to evaluate altered muscle properties in cerebral palsy.” Proceedings of ASME Dynamics Systems and Control

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KM Steele and S Lee (2014) “Using dynamic musculoskeletal simulation to evaluate altered muscle properties in cerebral palsy.” Proceedings of ASME Dynamics Systems and Control

Paper accepted at ASME Dynamics Systems and Control Conference:

Using dynamic musculoskeletal simulation to evaluate altered muscle properties in cerebral palsy

Abstract: Cerebral palsy is caused by an injury to the brain, but also causes many secondary changes in the musculoskeletal system. Altered muscle properties such as contracture, an increased passive resistance to stretch, are common but vary widely between individuals and between muscles. Quantifying these changes is important to understand pathologic movement and create patient-specific treatment plans. Musculoskeletal modeling and simulation have increasingly been used to evaluate pathologic movement in CP; however, these models are based upon muscle properties of unimpaired individuals. In this study, we used a dynamic musculoskeletal simulation of a simple motion, passively moving the ankle, to determine (1) if a model based upon unimpaired muscle properties can accurately represent individuals with cerebral palsy, and (2) if an optimization can be used to adjust passive muscle properties and characterize magnitude of contracture in individual muscles. We created musculoskeletal simulations of ankle motion for nine children with cerebral palsy. Results indicate that the unimpaired musculoskeletal model cannot accurately characterize passive ankle motion for most subjects, but adjusting tendon slack lengths can reduce error and help identify the magnitude of contracture for different muscles.

R Klemetti, KM Steele, P Moilanen, J Avela, J Timonen, (2014) “Contributions of individual muscles to the sagittal- and frontal-plane angular accelerations of the trunk in walking.” Journal of Biomechanics

Dr. Steele JournalArticle, MotorControl
R Klemetti, KM Steele, P Moilanen, J Avela, J Timonen, (2014) “Contributions of individual muscles to the sagittal- and frontal-plane angular accelerations of the trunk in walking.” Journal of Biomechanics

Journal article accepted in Journal of Biomechanics:

Contributions of individual muscles to the sagittal- and frontal-plane angular accelerations of the trunk in walking.

This study was conducted to analyze the unimpaired control of the trunk during walking. Studying the unimpaired control of the trunk reveals characteristics of good control. These characteristics can be pursued in the rehabilitation of impaired control. Impaired control of the trunk during walking is associated with aging and many movement disorders. This is a concern as it is considered to increase fall risk. Muscles that contribute to the trunk control in normal walking may also contribute to it under perturbation circumstances, attempting to prevent an impending fall. Knowledge of such muscles can be used to rehabilitate impaired control of the trunk. Here, angular accelerations of the trunk induced by individual muscles, in the sagittal and frontal planes, were calculated using 3D muscle-driven simulations of seven young healthy subjects walking at free speed. Analysis of the simulations demonstrated that the abdominal and back muscles displayed large contributions throughout the gait cycle both in the sagittal and frontal planes. Proximal lower-limb muscles contributed more than distal muscles in the sagittal plane, while both proximal and distal muscles showed large contributions in the frontal plane. Along with the stance-limb muscles, the swing-limb muscles also exhibited considerable contribution. The gluteus medius was found to be an important individual frontal-plane control muscle; enhancing its function in pathologies could ameliorate gait by attenuating trunk sway. In addition, since gravity appreciably accelerated the trunk in the frontal plane, it may engender excessive trunk sway in pathologies. PDF