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You searched for +publisher:"University of Texas – Austin" +contributor:("Wilken, Jason M"). Showing records 1 – 3 of 3 total matches.

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University of Texas – Austin

1. Ranz, Ellyn Cymbre. Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies.

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

Traumatic injuries to the extremities are commonly observed in emergency room patients and military personnel in combat. Restoring high mobility and functionality is a primary goal post-injury, which may require the use of rehabilitative devices, surgical interventions, and rehabilitation therapies. The research detailed in this dissertation investigates specific elements of these approaches through the use of experimental study and modeling and simulation. In the first study, the influence of passive-dynamic ankle-foot orthosis bending axis on the gait performance of limb salvage subjects was investigated. Bending axis location was altered by fabricating customized orthosis components using additive manufacturing and was tested in a gait laboratory. Altering bending axis location did not result in large or consistent changes in gait measures, however subjects expressed strong preferences for bending axis condition and preference was strongly related to specific gait measures. This suggests that preference and comfort are important factors guiding the prescription of bending axis location. In the second study, musculoskeletal modeling was used to examine the influence of transfemoral amputation surgical techniques on muscle capacity to generate forces and moments about the hip. Muscle reattachment tension and stabilization were shown to be critical parameters for post-amputation capacity, which supports the use of myodesis stabilization (muscle is reattached directly to bone) in amputation procedures. In the third study, a forward dynamics simulation of transfemoral amputee gait was developed and used to examine individual muscle and prosthesis contributions to walking subtasks. The residual hip muscles, and intact ankle, knee, and hip muscles worked synergistically to provide body support, anteroposterior propulsion, mediolateral control, and leg swing. Increased contributions of contralateral muscles to ipsilateral subtasks as well as increased duration of specific muscle contributions were observed in comparison to non-amputee and transtibial amputee walking. These findings can be used to help develop targeted rehabilitation therapies and improve transfemoral amputee locomotion. Through elucidating the influence of PD-AFO bending axis on gait performance as well as the influence of transfemoral amputation surgical techniques on muscle capacity and function, this research provides a foundation for improved rehabilitation outcomes, and thus mobility for individuals who have experienced traumatic lower-limb injuries. Advisors/Committee Members: Neptune, Richard R. (advisor), Barr, Ronald E (committee member), Crawford, Richard H (committee member), Sulzer, James S (committee member), Wilken, Jason M (committee member).

Subjects/Keywords: Biomechanics; Limb salvage; Transfemoral amputee; Additive manufacturing; Musculoskeletal modeling; Forward dynamics simulation

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

APA (6th Edition):

Ranz, E. C. (2016). Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/39695

Chicago Manual of Style (16th Edition):

Ranz, Ellyn Cymbre. “Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies.” 2016. Doctoral Dissertation, University of Texas – Austin. Accessed March 08, 2021. http://hdl.handle.net/2152/39695.

MLA Handbook (7th Edition):

Ranz, Ellyn Cymbre. “Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies.” 2016. Web. 08 Mar 2021.

Vancouver:

Ranz EC. Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2016. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/2152/39695.

Council of Science Editors:

Ranz EC. Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies. [Doctoral Dissertation]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/39695


University of Texas – Austin

2. Harper, Nicole Guckert. Muscle function and coordination of amputee and non-amputee stair ascent.

Degree: PhD, Mechanical engineering, 2015, University of Texas – Austin

Stair ascent is a common activity of daily living and is necessary for maintaining independence in a variety of community environments. However, it can be a biomechanically challenging task. For example, for transtibial amputees the loss of the ankle plantarflexors coupled with the task demands of stair ascent require amputees to develop compensatory mechanisms that utilize the prosthesis and remaining musculature. The overall goal of this research was to use advanced musculoskeletal modeling and simulation techniques in a series of studies to understand how individual muscles contribute to stair ascent in non-amputees and how unilateral transtibial amputees compensate with the prosthesis and remaining musculature during stair ascent. In the first study, a simulation of non-amputee stair ascent was developed to elucidate the contributions of individual muscles and the biomechanical mechanisms by which they accomplish stair ascent. The hip abductors, hip extensors, knee extensors and plantarflexors were found to work synergistically to generate, absorb and/or transfer mechanical power to accomplish stair ascent. In the second study, a simulation of transtibial amputee stair ascent was generated to identify functional deficits and compensations necessary for amputees to ascend stairs. The passive prosthesis was able to emulate the role of the uniarticular plantarflexors, but was unable to replicate the role of the biarticular plantarflexors. As a result, compensations from other muscles were necessary. In the final study, simulations of non-amputee and amputee stair ascent were used to determine the contributions of individual muscles and the prosthesis to dynamic balance control, which was quantified using whole-body angular momentum. The prosthesis was able to replicate the role of the plantarflexors in the regulation of sagittal-plane and, to a lesser extent, transverse-plane angular momentum. However, while the non-amputee plantarflexors contributed minimally to frontal-plane angular momentum, the prosthesis acted to rotate the body towards the contralateral leg, which required additional muscle compensations. By understanding the role of the individual muscles and prosthesis in achieving stair ascent and identifying the compensations used by amputees, this research provides a foundation for designing refined prostheses and targeted rehabilitation programs that improve an individual’s ability to ascend stairs. Advisors/Committee Members: Neptune, Richard R. (advisor), Barr, Ronald E (committee member), Deshpande, Ashish D (committee member), Sulzer, James S (committee member), Wilken, Jason M (committee member).

Subjects/Keywords: Stair ascent; Amputee; Forward dynamics; Modeling and simulation; Muscle contributions; Whole-body angular momentum

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

APA (6th Edition):

Harper, N. G. (2015). Muscle function and coordination of amputee and non-amputee stair ascent. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/31547

Chicago Manual of Style (16th Edition):

Harper, Nicole Guckert. “Muscle function and coordination of amputee and non-amputee stair ascent.” 2015. Doctoral Dissertation, University of Texas – Austin. Accessed March 08, 2021. http://hdl.handle.net/2152/31547.

MLA Handbook (7th Edition):

Harper, Nicole Guckert. “Muscle function and coordination of amputee and non-amputee stair ascent.” 2015. Web. 08 Mar 2021.

Vancouver:

Harper NG. Muscle function and coordination of amputee and non-amputee stair ascent. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2015. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/2152/31547.

Council of Science Editors:

Harper NG. Muscle function and coordination of amputee and non-amputee stair ascent. [Doctoral Dissertation]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/31547

3. Scott, Shawn James. The effects of walking speed and an uneven surface on dynamic stability margins in young adult subjects with and without traumatic unilateral trans-tibial amputations.

Degree: MA, Kinesiology, 2009, University of Texas – Austin

Dynamic stability is commonly defined as the ability to maintain balance through center of mass control during locomotion. Patients with locomotor impairments are especially challenged when walking over uneven surfaces (Richardson 2004). We studied dynamic stability margins in young healthy adults and in adults with unilateral traumatic trans-tibial amputations (TTA). To date, studies have not controlled for walking speed over an uneven surface in a patient population. We hypothesized that: 1) DSMs would increase over the uneven rocky surface (URS) for both groups, 2) DSMs would be greater on the involved side at faster walking speeds for subjects with TTA and, 3) DSMs would increase more for the involved limb when on the URS. 17 (4 females, 13 males) young healthy military service members (22.8 ± 6.4 years) and 12 (1 female, 11 males) service members (27.2 ± 4.7 years) with traumatic unilateral trans-tibial amputations participated in two study designs. A 15-segment model was used to estimate whole body COM motions. All subjects walked at 5 dimensionless speeds over a flat level surface (FLS) and an URS. Subjects completed 6-10 trials over each surface at each speed. Minimum frontal plane DSM values were extracted for each stride for statistical analyses. For young healthy subjects a two factor (speed x surface) ANOVA was used to test significance (p<.05). The DSMs were not greater over the URS (p=.307), but a main effect due to speed was found (p<.001) for young healthy subjects. In contrast, DSMs were significantly larger when subjects with TTA walked on the URS compared to the FLS (p = 0.011). For subjects with unilateral TTA, a three-factor ANCOVA ((amputation) side x speed x surface) with residual limb length (p=.029) and time in prosthesis (p=.741) as covariates was used for hypothesis testing. When limb length and time in prosthesis were accounted for there was no significant within subjects effect due to speed (p=.656). There were no significant differences between involved and uninvolved limbs (p = 0.211). There were no significant interaction effects. In conclusion, there was a difference in DSMs due to speed in unimpaired subjects and due to surface and residual limb length in subjects with unilateral TTAs. In subjects with unilateral TTA side-to-side symmetry was found for DSM measures, which was in contrast to an earlier study of subjects with unilateral trans-femoral amputations (Hof 2006). It appears that symmetry and dynamic stability are reasonable expectations for young adults with isolated TTAs. Advisors/Committee Members: Dingwell, Jonathan B. (advisor), Abraham, Larry (committee member), Jensen, Jody (committee member), Wilken, Jason M. (committee member), Childs, John (committee member).

Subjects/Keywords: Trans-tibial amputations; Walking; Dynamic stability; Speed; Surface

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

APA (6th Edition):

Scott, S. J. (2009). The effects of walking speed and an uneven surface on dynamic stability margins in young adult subjects with and without traumatic unilateral trans-tibial amputations. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/ETD-UT-2009-12-594

Chicago Manual of Style (16th Edition):

Scott, Shawn James. “The effects of walking speed and an uneven surface on dynamic stability margins in young adult subjects with and without traumatic unilateral trans-tibial amputations.” 2009. Masters Thesis, University of Texas – Austin. Accessed March 08, 2021. http://hdl.handle.net/2152/ETD-UT-2009-12-594.

MLA Handbook (7th Edition):

Scott, Shawn James. “The effects of walking speed and an uneven surface on dynamic stability margins in young adult subjects with and without traumatic unilateral trans-tibial amputations.” 2009. Web. 08 Mar 2021.

Vancouver:

Scott SJ. The effects of walking speed and an uneven surface on dynamic stability margins in young adult subjects with and without traumatic unilateral trans-tibial amputations. [Internet] [Masters thesis]. University of Texas – Austin; 2009. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/2152/ETD-UT-2009-12-594.

Council of Science Editors:

Scott SJ. The effects of walking speed and an uneven surface on dynamic stability margins in young adult subjects with and without traumatic unilateral trans-tibial amputations. [Masters Thesis]. University of Texas – Austin; 2009. Available from: http://hdl.handle.net/2152/ETD-UT-2009-12-594

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