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You searched for +publisher:"University of Texas – Austin" +contributor:("Klute, Glenn K"). Showing records 1 – 3 of 3 total matches.

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University of Texas – Austin

1. Shell, Courtney Elyse. Tuning prosthetic foot stiffness to improve lower-limb amputee mobility.

Degree: PhD, Mechanical Engineering, 2016, University of Texas – Austin

The foot, ankle and surrounding musculature play key roles in walking and maneuvering. They provide not only body support but also forward propulsion, terrain adaptation, and contributions to mediolateral balance control. Prosthetic feet have previously been designed to provide body support and, to some degree, forward propulsion and sagittal-plane terrain adaptation. However, there has been little exploration of how prosthesis design affects performance in tasks that challenge mediolateral balance, such as turning and walking on cross-slopes. In Chapter 2, the effects of prosthetic foot stiffness on unilateral transtibial amputee gait during turning were explored. Changes found in sagittal-plane kinematics and kinetics caused by more compliant prostheses were similar to those seen previously in studies of straight-line walking. This included decreased body support, increased residual limb propulsion and greater limb flexion. Mediolateral balance, measured by peak-to-peak range of whole-body angular momentum, improved with decreasing stiffness, but adaptations in coronal-plane angles, work and ground reaction force impulses were less systematic. In Chapter 3, forward dynamics simulations of a unilateral transtibial amputee stepping on a cross-slope were used to identify optimal coronal-plane stiffness profiles that improved balance control by decreasing changes in coronal-plane whole-body angular momentum. Profiles that decreased these changes were identified for ankle-inverting and ankle-everting cross-slopes as well as level ground. The change in coronal-plane whole-body angular momentum decreased with an increase in stiffness for ankle-everting cross-slopes but with a decrease in stiffness for ankle-inverting cross-slopes and level ground. Stiffness profiles influenced mediolateral balance control through the medial GRF, but were specific to each surface type. These results highlight the need to identify the surface type encountered (level, ankle-inverting or ankle-everting cross-slope) so that the stiffness profile appropriate for the surface can be set. To that end, in Chapter 4, measurements from the residual limb useful for predicting a cross-slope with a pattern recognition algorithm were identified. Residual limb kinematics, especially measurements from the foot, shank and ankle, were found to successfully predict the surface type with high accuracy. These studies have provided rationale and foundation for designing prostheses that help maintain mediolateral balance control when encountering turning or uneven terrain. Advisors/Committee Members: Neptune, Richard R. (advisor), Barr, Ronald E (committee member), Fey, Nicholas P (committee member), Klute, Glenn K (committee member), Sulzer, James S (committee member).

Subjects/Keywords: Transtibial amputee; Turning; Cross-slope; Gait; Dynamic balance; Forward dynamics simulation; Pattern recognition; Terrain prediction; Kinematics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Shell, C. E. (2016). Tuning prosthetic foot stiffness to improve lower-limb amputee mobility. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/68400

Chicago Manual of Style (16th Edition):

Shell, Courtney Elyse. “Tuning prosthetic foot stiffness to improve lower-limb amputee mobility.” 2016. Doctoral Dissertation, University of Texas – Austin. Accessed April 13, 2021. http://hdl.handle.net/2152/68400.

MLA Handbook (7th Edition):

Shell, Courtney Elyse. “Tuning prosthetic foot stiffness to improve lower-limb amputee mobility.” 2016. Web. 13 Apr 2021.

Vancouver:

Shell CE. Tuning prosthetic foot stiffness to improve lower-limb amputee mobility. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2016. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2152/68400.

Council of Science Editors:

Shell CE. Tuning prosthetic foot stiffness to improve lower-limb amputee mobility. [Doctoral Dissertation]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/68400

2. Womac, Nicholas David. Stiffness and energy storage characteristics of energy storage and return prosthetic feet.

Degree: MSin Engineering, Mechanical Engineering, 2017, University of Texas – Austin

Prosthetists currently lack quantifiable measures to guide prosthesis prescriptions and must rely on experience and manufacturer recommendations. Studies have shown that stiffness and energy storage characteristics of prosthetic feet significantly influence amputee gait. Consequently, several studies have attempted measure these mechanical characteristics, but typically measure only a few orientations in a single plane. This study examined the stiffness and energy storage characteristics of several prostheses over normal gait orientations with the goal of improving prosthesis prescriptions. Feet from five different manufacturers were tested with twenty-five different combinations of foot style, stiffness category and heel wedge inclusion. Force-displacement data were collected at fifteen sagittal orientations and five coronal orientations, and were used to calculate stiffness and energy storage. Loading conditions at each sagittal orientation were determined using a representative amputeeā€™s scaled walking data. Stiffness and energy storage were found to be highly non-linear in both the sagittal and coronal planes. Across all feet, stiffness was greatest near foot flat in the sagittal plane. Generally, stiffness decreased with greater heel, forefoot, medial and lateral loading orientations. Energy storage was greatest for forefoot loading and increased with medial or lateral loading orientations. As stiffness category increased within a foot style, stiffness increased and energy stored decreased. However, the recommended weight for a given foot was not linearly related to stiffness or energy storage. In addition, feet with similar manufacturer recommended weight ranges had varied energy storage over all orientations and varied stiffness over heel and foot flat loading orientations. Inclusion of heel wedges increased stiffness and decreased energy storage over heel and foot flat loading for the Vari-Flex with EVO foot, but not the Sierra foot. These results may help improve clinical prescriptions by providing prosthetists with quantitative measures to compare feet. Advisors/Committee Members: Neptune, Richard R. (advisor), Klute, Glenn K (committee member).

Subjects/Keywords: Prostheses; Stiffness; Energy storage

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Womac, N. D. (2017). Stiffness and energy storage characteristics of energy storage and return prosthetic feet. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/64116

Chicago Manual of Style (16th Edition):

Womac, Nicholas David. “Stiffness and energy storage characteristics of energy storage and return prosthetic feet.” 2017. Masters Thesis, University of Texas – Austin. Accessed April 13, 2021. http://hdl.handle.net/2152/64116.

MLA Handbook (7th Edition):

Womac, Nicholas David. “Stiffness and energy storage characteristics of energy storage and return prosthetic feet.” 2017. Web. 13 Apr 2021.

Vancouver:

Womac ND. Stiffness and energy storage characteristics of energy storage and return prosthetic feet. [Internet] [Masters thesis]. University of Texas – Austin; 2017. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2152/64116.

Council of Science Editors:

Womac ND. Stiffness and energy storage characteristics of energy storage and return prosthetic feet. [Masters Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/64116

3. -4098-9656. Balance recovery mechanisms used by below-knee amputees following mediolateral perturbations.

Degree: MSin Engineering, Mechanical Engineering, 2017, University of Texas – Austin

Lower limb amputees have a higher risk of falling compared to non-amputees. Proper regulation of whole-body angular momentum is necessary in order to prevent falls and is particularly important in the frontal plane as humans are most unstable in the mediolateral direction while walking. However, the balance recovery mechanisms used by lower limb amputees when recovering from a fall are not well understood. The purpose of this study was to understand the neuromuscular balance recovery mechanisms used by lower limb amputees in response to mediolateral balance perturbations by examining changes to frontal plane whole-body angular momentum, hip joint work, and ankle joint work. Ten amputees and 12 non-amputees participated in this study where an unexpected, repeatable lateral or medial perturbation disturbed the placement of the perturbed limb immediately prior to heel strike on the residual, sound or non-amputee limbs. Lateral perturbations of all limbs resulted in a reduced range of whole-body angular momentum (p=0.0048 for residual limb, and p<0.0001 for sound and non-amputee limbs) and increased positive frontal plane hip work for lateral perturbations of all limbs (p=0.0239 for the residual limb, p<0.0001 for both sound and non-amputee limbs). Medial perturbations for all limbs (p = 0.0030 for residual limb, p < 0.0001 for sound and non-amputee limbs) resulted in increased range of whole-body angular momentum and decreased positive frontal plane hip work (p < 0.0001 for all limbs). Medial perturbations of the sound (p = 0.0055) and non-amputee (p < 0.0001) limbs also resulted in an increase in the positive frontal plane ankle work. These results suggest that medial foot placement perturbations are particularly challenging to maintain balance and that hip and ankle strategies play an important role when recovering balance. Thus, rehabilitation interventions that focus on the hip and ankle muscles to regulate mediolateral balance, particularly the hip abductors and ankle plantarflexors, and use of prostheses with active ankle control may reduce the risk of falls. Advisors/Committee Members: Neptune, Richard R. (advisor), Klute, Glenn K (committee member).

Subjects/Keywords: Lower limb amputees; Whole-body angular momentum; Balance recovery mechanisms; Mediolateral perturbations; Below-knee amputees; Neuromuscular balance; Hip joint work; Ankle joint work; Foot placement perturbations

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

-4098-9656. (2017). Balance recovery mechanisms used by below-knee amputees following mediolateral perturbations. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/53146

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16th Edition):

-4098-9656. “Balance recovery mechanisms used by below-knee amputees following mediolateral perturbations.” 2017. Masters Thesis, University of Texas – Austin. Accessed April 13, 2021. http://hdl.handle.net/2152/53146.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7th Edition):

-4098-9656. “Balance recovery mechanisms used by below-knee amputees following mediolateral perturbations.” 2017. Web. 13 Apr 2021.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-4098-9656. Balance recovery mechanisms used by below-knee amputees following mediolateral perturbations. [Internet] [Masters thesis]. University of Texas – Austin; 2017. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2152/53146.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-4098-9656. Balance recovery mechanisms used by below-knee amputees following mediolateral perturbations. [Masters Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/53146

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

.