Mechanical Properties of Lower Limb Skin. A Natural Compression Stocking

Abstract The types of biomedical devices that can be three-dimensional printed (3DP) is limited by the mechanical properties of the resulting materials. As a result, much research has focused on adding carbon nanotubes (CNT) to these photocurable polymers to make them stronger. However, there is little to no data on how CNTs affect the impact resistance of these polymers, an important property when designing and manufacturing lower limb prosthetics. The objective of this study was to expand the use of 3DP to prosthetics by testing the hypothesis that adding CNTs to a stereolithographic (SLA) photocurable resin will result in a cured polymer with increased impact resistance. Twenty-six total specimens: 13 with nanotubes and 13 without nanotubes, were printed on a Form2 SLA printer. Once all the specimens were printed, washed, and cured, the impact resistance was quantified using a pendulum impact tester in a notched Izod configuration. Contrary to the hypothesis, the specimens with SWCNTs (0.312 ± 0.036 ft*lb/in) had a significantly lower impact resistance compared to the non-SWCNT specimens (0.364 ± 0.055 ft*lb/in), U = 34.0, p = 0.004. This decreased impact resistance may be due to voids in the printed polymer around the aggregated nanotubes. Thus, SLA polymers still do not have the impact strength needed to be used for a full lower limb prosthetic.

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Treatment strategies and clinical aspects of lower limb edema following peripheral bypass surgery

Phlebology The Journal of Venous Disease ◽

10.1177/0268355514527689 ◽

2014 ◽

Vol 29 (1_suppl) ◽

pp. 18-25

Author(s):

Alexander te Slaa ◽

Dennis Dolmans ◽

Gwan Ho ◽

Lijckle van der Laan

Keyword(s):

Quality Of Life ◽

Lower Limb ◽

Bypass Surgery ◽

Treatment Strategies ◽

Clinical Aspects ◽

Compression Stocking ◽

Compression Stockings ◽

Peripheral Bypass ◽

Limb Edema

In selected patients who suffer from severe peripheral artery disease (PAD) a revascularization with a peripheral bypass might be considered. Postoperative edema is a well-known phenomenon following peripheral bypass surgery and is probably caused by multiple factors. Although postoperative edema causes discomfort to patients, the effects on the quality of life are unknown. Treatment and preventive strategies should nonetheless aim at achieving a net absorption of fluid from the interstitial space into the vascular or lymphatic compartment. A brief summarization of treatment strategies of lower limb edema will be presented that include the use of compression stocking and intermittent pneumatic compression. So far, the postoperative application of compression stockings seem to prevent and reduce edema as much as possible. Quality of life improves slightly following peripheral bypass surgery. However, a contribution of edema on the quality of life could not be detected.

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Lower Limb Mechanical Properties: Significant References Omitted

Sports Medicine ◽

10.1007/s40279-012-0010-0 ◽

2012 ◽

Vol 43 (2) ◽

pp. 151-153 ◽

Cited By ~ 1

Author(s):

Jean-Benoit Morin ◽

Olivier Girard ◽

Jean Slawinski ◽

Giuseppe Rabita ◽

Georges Dalleau ◽

...

Keyword(s):

Mechanical Properties ◽

Lower Limb

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Effect of Shoes on Stiffness and Energy Efficiency of Ankle-Foot Orthosis: Bench Testing Analysis

Journal of Applied Biomechanics ◽

10.1123/jab.2016-0309 ◽

2017 ◽

Vol 33 (6) ◽

pp. 460-463 ◽

Cited By ~ 1

Author(s):

Toshiki Kobayashi ◽

Fan Gao ◽

Nicholas LeCursi ◽

K. Bo Foreman ◽

Michael S. Orendurff

Keyword(s):

Mechanical Properties ◽

Energy Efficiency ◽

Lower Limb ◽

Plantar Flexion ◽

Foot Orthoses ◽

Testing Device ◽

Ankle Foot Orthosis ◽

Ankle Foot Orthoses ◽

Bench Testing ◽

Foot Orthosis

Understanding the mechanical properties of ankle-foot orthoses (AFOs) is important to maximize their benefit for those with movement disorders during gait. Though mechanical properties such as stiffness and/or energy efficiency of AFOs have been extensively studied, it remains unknown how and to what extent shoes influence their properties. The aim of this study was to investigate the effect of shoes on stiffness and energy efficiency of an AFO using a custom mechanical testing device. Stiffness and energy efficiency of the AFO were measured in the plantar flexion and dorsiflexion range, respectively, under AFO-alone and AFO-Shoe combination conditions. The results of this study demonstrated that the stiffness of the AFO-Shoe combination was significantly decreased compared to the AFO-alone condition, but no significant differences were found in energy efficiency. From the results, we recommend that shoes used with AFOs should be carefully selected not only based on their effect on alignment of the lower limb, but also their effects on overall mechanical properties of the AFO-Shoe combination. Further study is needed to clarify the effects of differences in shoe designs on AFO-Shoe combination mechanical properties.

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Development of a Bimodal Ankle-Foot Prosthesis for Walking and Standing/Swaying

Journal of Medical Devices ◽

10.1115/1.4024646 ◽

2013 ◽

Vol 7 (3) ◽

Cited By ~ 8

Author(s):

Andrew H. Hansen ◽

Eric A. Nickel

Keyword(s):

Mechanical Properties ◽

Lower Limb ◽

Mechanical Stability ◽

Balance Confidence ◽

Prosthetic Foot ◽

Human Ankle ◽

Body Center ◽

Impaired Balance ◽

Prosthetic Feet ◽

Lower Height

The human ankle-foot system conforms to a circular effective rocker shape for walking, but to a much flatter effective shape for standing and swaying. Many persons with lower limb amputations have impaired balance and reduced balance confidence, and may benefit from prostheses designed to provide flatter effective rocker shapes during standing and swaying tasks. This paper describes the development and testing of an ankle-foot prosthesis prototype that provides distinctly different mechanical properties for walking and standing/swaying. The prototype developed was a single-axis prosthetic foot with a lockable ankle for added stability during standing and swaying. The bimodal ankle-foot prosthesis prototype was tested on pseudoprostheses (walking boots with prosthetic feet beneath) for walking and standing/swaying loads, and was compared to an Otto Bock single-axis prosthetic foot and to able-bodied data collected in a previous study. The height-normalized radius of the effective rocker shape for walking with the bimodal ankle-foot prototype was equal to that found earlier for able-bodied persons (0.17); the standing and swaying effective shape had a lower height-normalized radius (0.70) compared with that previously found for able-bodied persons (1.11). The bimodal ankle-foot prosthesis prototype had a similar radius as the Otto Bock single-axis prosthetic foot for the effective rocker shape for walking (0.17 for both), but had a much larger radius for standing and swaying (0.70 for bimodal, 0.34 for single-axis). The results suggest that the bimodal ankle-foot prosthesis prototype provides two distinct modes, including a biomimetic effective rocker shape for walking and an inherently stable base for standing and swaying. The radius of the prototype's effective rocker shape for standing/swaying suggests that it may provide inherent mechanical stability to a prosthesis user, since the radius is larger than the typical body center of mass’s distance from the floor (between 50–60% of height). Future testing is warranted to determine if the bimodal ankle-foot prosthesis will increase balance and balance confidence in prosthesis users.

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Characterising the Soft Tissue Mechanical Properties of the Lower Limb of a Below-Knee Amputee: A Review

Computational Biomechanics for Medicine ◽

10.1007/978-3-030-70123-9_8 ◽

2021 ◽

pp. 99-111

Author(s):

Seyed Sajad Mirjavadi ◽

Andrew J. Taberner ◽

Martyn P. Nash ◽

Poul M. F. Nielsen

Keyword(s):

Mechanical Properties ◽

Soft Tissue ◽

Lower Limb

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