Background: Cosmesis has been found to have an impact on prosthesis users' body image. Therefore the satisfaction of the cosmesis plays an essential role in a prosthesis user perception of themselves. Most cosmeses on the market are natural-looking, although more futuristic options are coming to the market. Most of the previous evidence has been conducted using quantitative methods. There is a lack of research investigating the experiences of cosmesis in transtibial prosthesis users through qualitative methods. This is expected to elucidate potentially undiscovered areas and factors surrounding patient satisfaction.  Purpose: The aim of this thesis is to explore transtibial prosthesis user's satisfaction with the appearance of their cosmesis and gain a deeper understanding of their experiences regarding cosmeses.  Methods: The method in this thesis is a qualitative phenomenology approach with an interpretivist view. The experiences of 5 male transtibial users regarding their cosmesis and satisfaction towards it were explored. This was done by having in-depth semi-structured interviews that were analyzed with thematic analysis.  Results: The results five main themes arrived: Satisfaction, Natural-looking cosmesis, Function, Difficulties with the material, and Awareness. The results of these themes showed that the participants have different experiences regarding cosmesis.  Conclusion: This thesis found a variation regarding satisfaction of the appearance among unilateral transtibial prosthesis users. Similarities in satisfaction and experience were found in the respective age groups of the participants. However, due to saturation not being fully reached, there should be further investigations. / Bakgrund: Kosmetik har visat sig påverka protesanvändarnas kroppsuppfattning. Därför spelar tillfredsställelsen av kosmetiken en viktig roll i en protesanvändares mentala hälsa och kroppsuppfattning. Huvuddelen av den kosmetik som finns på marknaden har ett mer naturligt utseende, även om mer futuristiska alternativ har blivit mer vanliga på marknaden. De flesta av de tidigare redovisade studierna har genomförts med hjälp av kvantitativa forskningsmetoder. Det saknas ännu forskning som undersöker erfarenheterna när det gäller kosmetik hos transtibialt amputerade protesanvändare utförda med kvalitativa metoder. Studien förväntas belysa potentiellt oupptäckta områden och faktorer kring patientnöjdhet. Syfte: Syftet med denna studie är att utforska transtibialt amputerade protesanvändares tillfredsställelse med utseendet på deras kosmetik och få en djupare förståelse för deras erfarenheter av kosmetik. Metoder: I denna avhandling är ett kvalitativt fenomenologiskt tillvägagångssätt med ett interpretivistiskt förhållningssätt. Erfarenheter från 5 manliga transtibialt amputerade protesanvändare med avseende på proteskosmetik och deras tillfredsställelse med användandet kosmetik undersöktes. Detta genomfördes genom att ha djupgående halvstrukturerade intervjuer som analyserades med ett tematiskt förhållningssätt. Resultat: I resultaten framkom i huvudsak 5 huvudtema: Tillfredsställelse, kosmetik med naturligt utseende, funktion, svårigheter med material och medvetenhet. Resultaten av dessa teman visade att deltagarna har stora variationer när det gäller erfarenheter och användandet av kosmetik. Slutsats: Denna studie fann en betydande variation när det gäller tillfredsställelse av utseendet bland ensidiga användare av transtibiala proteser. Likheter inom tillfredsställelse och erfarenhet kunde noteras i deltagarnas respektive åldersgrupper. På grund av att mättnad (saturation) inte uppnåddes helt finns ett forsatt behov av ytterligare studier inom området.

While amputee gait has been studied in great detail, the influence of prosthetic foot sagittal and coronal plane stiffness on amputee walking biomechanics is not well understood. In order to investigate the effects of sagittal and coronal plane foot stiffness on amputee walking, a framework for manipulating the stiffness of a prosthetic foot needs to be developed. The sagittal and coronal plane stiffness of a low profile carbon fiber prosthetic foot was manipulated through coupling with selective-laser-sintered prosthetic ankles. The carbon fiber foot provided an underlying non-linear stiffness profile while the ankle modified the overall stiffness of the ankle-foot combination. A design of experiments was performed to determine the effect of four prosthetic ankle dimensions (keel thickness, keel width, space between the ankle top and bottom faces, and the location of the pyramid connection) on ankle-foot sagittal and coronal plane stiffness. Ankles were manufactured using selective laser sintering and statically tested to determine stiffness. Two of the dimensions, space between the ankle top and bottom faces and the location of the pyramid connection, were found to have the largest influence on both sagittal and coronal plane stiffness. A third dimension, keel thickness, influenced only coronal plane stiffness. A number of prosthetic ankle-foot combinations were created that encompassed a range of sagittal and coronal plane stiffness levels that were lower than that of the low profile carbon fiber foot alone. To further test the effectiveness of the framework to manipulate sagittal and coronal plane stiffness, two ankle-foot combinations, one stiffer than the other in the sagittal and coronal planes, were used in a case study analyzing amputee walking biomechanics. Differences in stiffness were large enough to cause noticeable changes in amputee kinematics and kinetics during turning and straight-line walking. Future work will expand the range of ankle-foot stiffness levels that can be created using this framework. The framework will then be used to create ankle-foot combinations to investigate the effect of sagittal and coronal plane stiffness on gait mechanics in a large sample of unilateral transtibial amputees. / text

Unilateral, below-knee amputees have altered gait mechanics, which can significantly affect mobility. For example, amputees often have asymmetric leg loading as well as higher metabolic cost and an increased risk of falling compared to non-amputees. Below-knee amputees lose the functional use of the ankle muscles, which are critical in non-amputee walking for providing body support, forward propulsion and leg-swing initiation. The ankle muscles also regulate angular momentum in non-amputees, which is important for providing body stability and preventing falls. Thus, compensatory mechanisms in amputee walking are developed to accomplish the functional tasks normally provided by the ankle muscles. In Chapters 2 and 3, three-dimensional forward dynamics simulations of amputee and non-amputee walking were generated to identify compensatory mechanisms and their effects on joint loading and metabolic cost. Results showed that the prosthesis provided body support, but did not provide sufficient body propulsion or leg-swing initiation. As a result, compensations by the residual leg gluteus maximus, gluteus medius, and hamstrings were needed. The simulations also showed the intact leg tibio-femoral joint contact impulse was greater than the residual leg and that the vasti and hamstrings were the primary contributors to the joint impulse on both the intact and residual legs. The amputee simulation had higher metabolic cost than the non-amputee simulation, which was primarily due to prolonged muscle activity from the residual leg gluteus maximus, gluteus medius, hamstrings, vasti and intact leg vasti and ankle muscles. In Chapter 4, whole-body angular momentum in amputees and non-amputees was analyzed. Reduced residual leg propulsion resulted in a smaller range of sagittal plane angular momentum in the second half of the gait cycle. Thus, to conserve angular momentum, reduced braking was needed in the first half of the gait cycle. Decreased residual leg braking appears to be an important mechanism to regulate sagittal plane angular momentum in amputee walking, but was also associated with a greater range of angular momentum that may contribute to reduced stability in amputees. These studies have provided important insight into compensatory mechanisms in below-knee amputee walking and have the potential to guide rehabilitation methods to improve amputee mobility. / text

For pediatric amputees in developing countries, where characteristically rapid growth of children is compounded by a lack of medical services, maintaining proper socket fit is a challenging but necessary endeavor. A socket design that adjusts for radial and longitudinal growth will allow patients to wear the same socket for a longer period of time saving them the expense of subsequent fittings and hardware. Manufacture of such a socket poses a challenge for contemporary manufacturing processes. Due to its ability to rapidly manufacture complex part geometries, Selective Laser Sintering (SLS) is particularly suited to this application. Several preliminary design concepts for a volume adjustable transtibial SLS prosthetic socket for pediatric amputees in developing countries have been generated. These current design concepts utilize fasteners such as ratchet hooks and threads. Results from design and validation of theoretical models of these fastener concepts are the focus of this thesis. / text

For many years, the biggest issue that causes discomfort and hygiene issues for patients with lower limb amputations have been the interface between body and prosthetic, the socket. Often made of an inflexible, solid polymer that does not allow the residual limb to breathe or perspire and with no consideration for the changes in size and shape of the human body caused by changes in temperature or environment, inflammation, irritation and discomfort often cause reduced usage or outright rejection of the prosthetic by the patient in their day to day lives. To address these issues and move towards a future of improved quality of life for patients who suffer amputations, Loughborough University formed the Next Generation Prosthetics research cluster. This work is one of four multidisciplinary research studies conducted by members of this research cluster, focusing on the area of Computer Aided Design (CAD) for improving the interface with Additive Manufacture (AM) to solve some of the challenges presented with improving prosthetic socket design, with an aim to improve and streamline the process to enable the involvement of clinicians and patients in the design process. The research presented in this thesis is based on three primary studies. The first study involved the conception of a CAD criteria, deciding what features are needed to represent the various properties the future socket outlined by the research cluster needs. These criteria were then used for testing three CAD systems, one each from the Parametric, Non Uniform Rational Basis Spline (NURBS) and Polygon archetypes respectively. The result of these tests led to the creation of a hybrid control workflow, used as the basis for finding improvements. The second study explored emerging CAD solutions, various new systems or plug-ins that had opportunities to improve the control model. These solutions were tested individually in areas where they could improve the workflow, and the successful solutions were added to the hybrid workflow to improve and reduce the workflow further. The final study involved taking the knowledge gained from the literature and the first two studies in order to theorise how an ideal CAD system for producing future prosthetic sockets would work, with considerations for user interface issues as well as background CAD applications. The third study was then used to inform the final deliverable of this research, a software design specification that defines how the system would work. This specification was written as a challenge to the CAD community, hoping to inform and aid future advancements in CAD software. As a final stage of research validation, a number of members of the CAD community were contacted and interviewed about their feelings of the work produced and their feedback was taken in order to inform future research in this area.

Osteoarthritis (OA) is a debilitating disease affecting roughly 31 million Americans. The incidence of OA is significantly higher for persons who have suffered a transtibial amputation. Abnormal cartilage stress can cause higher OA risk, however it is unknown if there is a connection between exercise type and cartilage stress. To help answer this, a tibiofemoral FEA model was created. Utilizing linear elastic isotropic materials and non-linear springs, the model was validated to experimental cadaveric data. In a previous study, 6 control and 6 amputee subjects underwent gait and cycling experiments. The resultant knee loads were analyzed to find the maximum compressive load and the respective shear forces and rotation moments for each trial, which were then applied to the model. Maximum tibial contact stress values were extracted for both the medial and lateral compartments. Only exercise choice in the lateral compartment was found to be a significant interaction (p<0.0001). No other interactions in either compartment were significant. This suggests that cycling reduces the risk for lateral OA regardless of amputation status and medial OA risk is unaffected. This study also developed a process for creating subject-specific FEA models.

Transtibial amputees are at increased risk of contralateral hip and knee joint osteoarthritis, likely due to abnormal biomechanics. Biomechanical challenges exist for transtibial amputees in gait and cycling; particularly, asymmetry in ground/pedal reaction forces and joint kinetics is well documented and state-of-the-art passive and powered prostheses do not fully restore natural biomechanics. Elliptical training has not been studied as a potential exercise for rehabilitation, nor have any studies been published that compare joint kinematics and kinetics and ground/pedal reaction forces for the same group of transtibial amputees in gait, cycling, and elliptical training. The hypothesis was that hip and knee joint kinematics and kinetics and ground and pedal reaction forces would differ due to exercise (gait, cycling, elliptical) amputee status (amputated, control [non-amputated]), and leg (dominant [intact], non-dominant [amputated]). Ten unilateral transtibial amputees and ten control participants performed the three exercises while kinematic and kinetic data were collected. Hip and knee joint flexion angle, resultant forces, and resultant moments were calculated by inverse dynamics for the dominant and non-dominant legs of both participant groups. Joint biomechanics and measured ground/pedal reaction forces were then compared between exercises, between the dominant and non-dominant legs within each participant group, and across participant groups. Significant differences in hip and knee joint flexion angles and timing, compressive forces, extension-flexion (EF) and adduction-abduction (AddAbd) moments, and anterior-posterior (AP) and lateral-medial (LM) reaction forces were found. Particularly, transtibial amputees showed maximum knee flexion angle asymmetry as compared to controls in all three exercises. Maximum hip and knee compressive forces, EF moments, and AddAbd moments were lowest in cycling and highest in gait. Asymmetry in amputee midstance knee flexion and timing in v gait, coupled with low maximum EF moment for the non-dominant leg, suggests that amputees avoid contraction of the non-dominant quadriceps muscle. Knee flexion angle and EF moment asymmetry in elliptical training suggests that a similar phenomenon occurs. Asymmetry in AP and LM reaction forces in gait, but not other exercises, suggests that exercises that constrain kinematics reduce loading imbalances. The results suggest that cycling and elliptical training should be recommended to transtibial amputees for rehabilitation due to reduced hip and knee joint forces and moments. Elliptical training may be preferred over gait due to decreased joint loading and loading asymmetry, but some asymmetry and differences from control participants still exist. Non-weight bearing exercises such as cycling may be best at reducing overall joint loading and joint load asymmetry but do not eliminate all kinematic and temporal asymmetries. Current state-of-the-art prosthetic leg design is insufficient in restoring natural biomechanics not only in gait but also in cycling and elliptical training. Improved prosthesis kinematics that restore non-dominant knee flexion in amputees to normal levels could help reprogram quadriceps muscle patterns in gait and elliptical training and hip and knee joint biomechanical asymmetries. Further work in comparing contralateral and prosthesis ankle joint biomechanics would help to elucidate the relationship between prosthesis design and its impact on lower limb joint biomechanics.

The thesis deals with the design of a transtibial prosthesis by additive manufacturing technology. Based on walking biomechanics and the current situation of knowledge a prosthetic foot has been designed for a patient with low level of physical activity. Furthermore, the thesis describes the design of an individual socket for the patient. The socket has been designed by reverse engineer procedure based on the three-dimensional geometry of patient´s stump obtained by 3D scanning. Testing samples of the foot and the socket have been made for the check of functionality of both the devices and then subjected to mechanical tests in accordance to the methodology regulation ISO 10328. Finally, the thesis depicts the FDM technology used for the production of functional samples of the designed devices; assembly of modular transtibial prosthesis and its testing by the patient.

This thesis deals with the construction of an active transtibial prosthesis for recreational swimming. Its aim is to create a working sample of such a prosthesis. The device will primarily serve the patient to move in water - it will be attached to the stump and it will be driven forward. Secondarily, the prosthesis can be used for walking, in the sense that the patient attaches the prosthesis near to a water surface (pool, lake, ocean) and comes with it to the shore. As part of the design and electronics it will be necessary to determine the characteristics of the human resistance in water depending on speed and to determine the necessary propulsion (thrust) strength of the propeller, which will serve as the driving force. Subsequently there will be formed structural variants and selected the best one. This will become default for design and construction of simplified testing device, which will be tested for static thrust. After verifying the functionality and reliability, the final functional sample will be manufactured and tested too.

Syfte: Syftet med det här examenarbete är att undersöka behovet av snabbkopplingsadaptrar för protesbrukare.   Bakgrund: Snabbkopplingsadapter är en förhållandevis ny produkt som både Otto Bock och Lindhe Xtend erbjuder, men ingen forskning på behovsområdet finns ännu gjord. Fördelen med produkten är enligt leverantörernas hemsidor bl a att man med den enkelt kan byta mellan olika proteskomponenter utan att behöva skruva på några protesinställningar eller byta hylsa.   Metod: För att undersöka behovet av snabbkopplingsadaptrar utfördes semistrukturella intervjuer av fenomenologisk karaktär. En serie med sju frågor sammanställdes som intervjuunderlag, vilka togs fram utifrån de tre behovsfokusområdena: Funktion, delaktighet och livskvalité. I undersökningen ingick n=6 deltagare, varav n=3 transtibialt amputerade och n=3 transfemoralt amputerade. Insamlade data analyserades vidare för framtagning av olika teman och resultat.   Resultat: Utifrån intervjuunderlaget togs följande teman fram: Byte av protesfötter/protesknäleder, På- och avtagning av byxor, Hylspassform, Transport samt Biomekanik. Varje tema utgjorde ett eget potentiellt användningsområde, där de största behoven visade sig ligga inom temana Byte av protesfötter/protesknäleder, Hylspassform samt Transport.   Slutsats: Behovet av snabbkopplingsadaptrar är högst subjektivt, och beror snarare på deltagarens liv än några allmänna faktorer. Däremot upptäcktes ett antal tänkbara användningsområden för den. / Aim: The aim of this thesis was to investigate the necessity of the quick change adapter for lower limb amputees.   Background: Quick Change Adapter is a relatively new product that both Otto Bock and Lindhe Xtend offers, but no research has been done on the area of its necessity yet.  According to the supplier´s websites the benefits of the product is that you with it easily can change prosthetic components without affecting the alignments or change socket.   Method: To investigate the necessity of the Quick Change Adapter, semi structural interviews of phenomenological characteristic were used.  A series of seven questions were compiled as a basis for the interview from the three focus areas: Function, participation and quality of Life. The thesis involved n=6 participants, of who n=3 was trantibial amputated and n=3 transfemoral amputated. Collected data was later analysed to find general themes and results.   Results: From the interviews these themes were exposed: Changing prosthetic feet/prosthetic knee joints, Donn and doff of pants, Socket fit, Transport and Biomechanics. Each theme presented a potential application area where the biggest needs seemed to be in Changing prosthetic feet/prosthetic knee joints, Socket fit and Transport.   Conclusions: The necessity of the Quick Change Adapter turned out to be very subjective, and depended more on the participant´s life then any general factors. Still there were some potential application areas detected for it.