<p>This study explored the history, present status, and future trends in assistive technologies and innovations in lower limb prosthesis. The study analyzed trends in patent filing and looked into how mainstream technologies such as additive manufacturing, advanced materials and robotic integrate with other enabling technologies such as IoT, AI, sensors etc. to advance technology innovation and improve the quality of life of people with limb impairment.</p> <p><br></p> <p>This research study is significant in helping to understand what is on the horizon for people with lower limb impairment given that this population tend to be neglected and their needs have not been fully addressed in many areas</p>

Basal cell carcinoma is an indolent, slow-growing tumor that rarely metastasizes. Approximately 70% of tumors occur in the head and neck regions. If a basal cell tumor metastasizes, it usually spreads to the regional lymph nodes first, followed by the lungs. We describe a patient with basal cell carcinoma of the right lower extremity with skin metastases. Skin biopsy of one tumor revealed fibroepithelioma of Pinkus, a rare variant of basal cell carcinoma.

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Ballistic shields are supported by a user’s arm, placing the upper extremity at close proximity to the back-face of the shield. Although ballistic shields must pass a protective standard that outlines projectile (bullet) penetration; there is no standard that stipulates the amount of acceptable deformation when ballistic shields stop or deflect projectiles. There are no injury criteria developed for the high-rate, short duration and focal loading that is typical of shield back-face deformation from these events. In this research, an anthropomorphic test device (ATD) was modified to allow for additional instrumentation capable of measuring these loads. It was then used in a ballistic testing facility to quantify loading at the hand, wrist, forearm, and elbow. A lightweight projectile was created that matched the shape and stiffness of the deforming ballistic shield and impacts within 5% of the peak force measured in the ballistic testing facility were applied with it to post-mortem human subjects (PMHS) until failure. Eight 50th percentile male PMHS pairs were segmented at the mid-humerus and impacted to failure to determine the fracture threshold of the hand, wrist, forearm, and elbow, confirmed by x-ray imaging. The peak force required to generate fracture varied significantly among anatomical location, indicating boundary conditions influence failure threshold. Further, these injury criteria were substantially different than previously reported criteria for other loading events (e.g., automotive), highlighting the importance of developing injury criteria specific for the intended application. An existing finite element human body model designed for automotive impacts was also assessed for its applicability to predict injury in these high-rate loading scenarios, and performed well for peak force, but not for the force-time curve shape. This is the first study of its kind to assess injury risk resulting from shield behind armour blunt trauma, and results from this work will inform a protective standard to assess ballistic shields. / Thesis / Doctor of Philosophy (PhD) / Ballistic shields used by defence personnel are designed to stop incoming bullets by deflecting or absorbing them. In the process, the back-face of the shield undergoes a rapid deformation that can potentially cause an upper extremity injury to users, an injury mechanism termed behind shield blunt trauma. This work aimed to quantify the injury risk that this mechanism poses at four locations along the upper extremity: the hand, wrist, forearm, and elbow. This was conducted by modifying and employing a crash test dummy upper extremity and measuring loads applied to the upper extremity in a ballistic testing range. Assessment of whether these loads caused injury was conducted using cadaveric specimens and testing them to failure. An existing finite element human body model was also assessed for its applicability to predict injury in these high-rate loading scenarios. Results from this work will inform a protective standard to assess ballistic shields.

The single leg squat (SLS) is a functional movement task that is commonly used by clinicians as both an evaluation and treatment tool. Across clinics and research labs, no standard SLS procedure exists and variations in non-stance leg position are typical. There is little information to guide clinicians in selecting the appropriate SLS variation for individual rehabilitation goals. Non-stance leg positioning during the SLS may influence lower extremity mechanics and muscle activity. It is unknown if, and to what extent, altering the non-stance leg position during the SLS affects how the SLS is performed. The purpose of this dissertation was to examine how healthy adults performed the SLS when asked to place their non-stance leg in 3 commonly used positions during the squat. We hypothesized that the position of the non-stance leg would have a nontrivial impact on how the SLS was performed and result in different stance leg mechanics and muscle activation levels. Sixteen females participated in Study 1, the same 16 females from Study 1 and 16 males participated in Study 2, and 17 adults (with some overlap of participants from Study 1 and Study 2) participated in Study 3. Kinematic data were recorded using a motion capture system, ground reaction force data were collected using the force plates in a split-belt instrumented treadmill, and muscle activity levels were quantified using a surface electromyography system. Results from all 3 studies supported our hypothesis. Study 1 indicated that different non-stance leg positions during the SLS affected the kinematics at the trunk, pelvis, and lower extremity and the lower extremity kinetics in females. Study 2 demonstrated that males also exhibited different kinematics and kinetics for the 3 SLS tasks with different non-stance leg positions. In addition, females and males performed the 3 SLS tasks differently, suggesting that they respond differently to altering the non-stance leg position. Study 3 indicated that hip muscle activation levels were affected by the non-stance leg position during the SLS. Our results suggest that clinicians and researchers should be mindful of the non-stance leg position during the SLS and be cautious of using SLS variations interchangeably. / 2021-06-30T00:00:00Z

Joint kinematics of upper extremity (UE) impairments in a pediatric population are often difficult to examine using marker-based motion capture. As a result of the cost and availability of tools such as marker-based motion capture in clinical settings, clinicians use functional tasks to examine improvement in movement quality. However, some of these tasks, such as the Box and Block test (BBT), which is examined in this study, rely on scoring to assess motor improvement. This scoring method can be misleading due to the possibility of movement compensation to improve scores. Therefore, finding kinematic correlations that can lead to improved BBT scores could improve the quality of functional assessments by providing discrete measures for clinicians. Understanding human motion using marker-based motion capture has been the accepted standard in biomechanics. However, it is not without its drawbacks, especially in upper extremity examination due to complex anatomical positioning. The introduction of markerless motion capture software could drastically alter how human biomechanics is analyzed in various settings. Additionally, avoiding possible errors due to clothing and skin movement could greatly improve reported results. Therefore, examining similarities in UE joint kinematics between accepted marker-based and markerless software could introduce markerless motion capture as a method for examining complex kinematics. This study aims to examine UE joint kinematics in a typically developing pediatric population while they complete the BBT, as well as validate Theia3D (Theia Markerless Inc., Kingston, ON, Canada). Marker-based motion capture was used to capture UE kinematics during the BBT. This study was performed on typically developing children aged 7, 9, and 11. Average and peak joint angles were determined, as well as hand segment velocity and path length. Significant correlations to BBT scores were found in peak shoulder flexion (FLEX) angle (r = -0.556, p-value = 0.009), peak (r = -0.479, p-value = 0.028), and average (ρ = -0.535, p-value = 0.012) wrist extension (EXT) angle, average mediolateral (ML) hand segment velocity (r = 0.494, p-value = 0.023), and path length (r = -0.522, p-value = 0.015). Additionally, significant differences between BBT scores (p-value = 0.005), peak shoulder FLEX (p-value = 0.024), and peak shoulder abduction (ABD) angle (p-value = 0.022) were found between the 7- and 11-year-old age groups. Peak elbow FLEX angle was significantly different (p-value = 0.049) between 9- and 11-year-old age groups. These results show that the BBT score could be related to the shoulder and wrist angle, as well as hand segment velocity and path length for typically developing children. Furthermore, root mean square deviation (RMSD) values less than 6° existed in all joint angles. Intraclass correlation coefficients (ICCs) greater than 0.75 were found in shoulder ABD (ICC = 0.79), forearm pronation (ICC = 0.81), wrist EXT (ICC = 0.75), and radial deviation (ICC = 0.87). Additionally, validation results between the marker-based and markerless systems show that there are differences in pose estimations and joint calculations based on rotation sequences. Overall, UE joint kinematics are shown to have correlations to BBT scores, so scores alone may not be indicative of movement quality in other patient populations. Markerless motion capture shows many benefits, however, it should be noted that, due to the complexity of upper extremity motion analysis, understanding what joint rotation sequences align the best with task-specific motions is important. / Master of Science / Human motion is commonly analyzed using marker-based motion capture, which consists of fitting participants with retroreflective markers that can be seen by specialized cameras. However, due to equipment costs, difficult implementation, and the occurrence of markers shifting on skin or being concealed by clothing, markerless motion capture is beginning to be introduced into biomechanics research and could be used in hospitals, clinical settings, and for outdoor examination due to its versatility. The software uses machine learning software that can determine skin landmarks in videos from several cameras to develop a 3D skeleton. Markerless motion capture could be beneficial in examining patients with neuromotor disorders or injuries due to being able to capture abnormal or quick movement which often accompanies many neurological disorders that affect motor function. Additionally, observing movement in children is a challenge due to markers being too close together on smaller limbs. Due to cost and obtainability, clinicians tend to use functional tests to examine improvements in motor function by a scoring system relevant to the specific test, such as the Box and Block test (BBT) which will be used in this study. However, there is the possibility of the patient's ability to adapt to the test to improve their score without improving general motor function. Therefore, it is important to find a relationship between upper limb movement and BBT scores. This study aims to find correlations between upper limb movement and Box and Block test scores as well as differences between 7-, 9-, and 11-year-old age groups and compare marker-based motion capture and the Theia3D (Theia Markerless Inc., Kingston, ON, Canada) markerless motion capture software. Joint assessment is completed with motion capture, which uses reflective markers on specific landmarks on the skin surface. Markerless motion capture is collected simultaneously with marker-based motion capture to assess similarities. The entire procedure was also completed 2 times within 1 visit. The results showed meaningful comparisons between the BBT scores and shoulder and wrist angle, and hand velocity. BBT scores and shoulder angles were shown to be different between the 7- and 11-year-old age groups. Elbow angles were shown to be different between the 9- and 11-year-old age groups. Additionally, comparisons between the marker-based and markerless results showed that all resulting joint angle data captured by each system were similar. Markerless measurement comparisons showed similarities between both sessions as well. These results show that there are ways to provide discrete measurements in clinical settings to examine movement quality. Comparisons between both motion analysis systems show the need to determine task-specific analyses to obtain meaningful results concerning the upper limbs, due to the inherent joint complexity and differing methods of completing the same task.

Obese and older adults are reported to have a higher rate of mobility limitation and are at a higher risk of fall compared to healthy-weight and young counterparts. To help identify potential mechanisms of these mobility limitations and higher risk of falls, the purpose of the research within this dissertation was to investigate the effects of obesity and age on muscle strength, gait, and balance recovery. Three experimental studies were conducted. The purpose of the first study was to investigate the effects of obesity and age on extension and flexion strength at the hip, knee, and ankle. Absolute strength among obese participants was higher in dorsiflexion, knee extension, and hip flexion compared to healthy-weight participants. Strength relative to body mass was lower among obese participants in all joints/exertions. This lack of uniformity across the 6 exertions is likely due to the still unclear underlying biomechanical mechanism responsible for these strength differences, which may also be influenced by aging. The purpose of the second study was to investigate the effects of obesity, age and, their interactions on relative effort at the hip, knee, and ankle during gait. The peak relative effort for each joint/exertion was expressed by peak NMM during gait as a percentage of the maximum available NMM. The relative effort in hip, knee, and ankle was higher among obese compared to healthy-weight participants. This higher relative effort in hip, knee, and especially in the ankle can be a contributing factor to compromised walking ability among obese individuals. The purpose of the third study was to investigate the effects of age-related strength loss on non-stepping balance recovery capability after a perturbation while standing, without constraining the movements to ankle strategy. The balance recovery capability was quantified by the maximum recoverable platform displacement (MRPD) that was withstood without stepping. Two experiments were conducted. The first experiment involved human subjects and the results suggested that MRPD was lower among older participants compared to young participants. The second experiment involved a simulation study to manipulate muscle strength at hip, knee, and ankle. The results suggested that MRPD was reduced in cases of loss of strength in ankle plantar flexion and hip flexion compared to the young model and did not differ in rest of the cases. The finding suggested that plantar flexor strength plays a major role in capability to recover balance even though the movement was not constrained to the ankle. / Ph. D.

During an under-body blast (UBB) event, an improvised explosive device (IED) delivers a high-energy blast beneath a military vehicle, exposing mounted Warfighters to considerable risk of severe lower extremity injuries. Loftis and Gillich (2014) determined that the lower leg and ankle region is the most common body region to sustain skeletal injury in military mounted combat events, comprising twenty-one percent of cases reported in the Joint Trauma Analysis and Prevention of Injuries in Combat (JTAPIC) database between 2010 and 2012. Injuries of the lower extremity are not always life-threatening. However, from a survivability standpoint, these injuries may affect the ability of the Warfighter to self-extricate and ambulate in the immediate aftermath of an UBB event. In addition, lower extremity injuries can lead to long term health complications and reduced quality of life (Dischinger et al., 2004). While some comparisons can be drawn from the study of civilian automotive crashes; the impact level, rate, location, and directions in UBB are fundamentally different for the lower extremity. Therefore, substantial research efforts to characterize and assess injuries unique to UBB are essential. The Warrior Injury Assessment Manikin (WIAMan), the Tech Demonstrator version of which was introduced by Pietsch et al. (2016), is the only anthropomorphic test device (ATD) designed to evaluate injury patterns in UBB conditions. However, there are no known injury assessment tools for the female Warfighter at this time. The overarching goal of this research effort is to determine the origin of potential differences in the response of females and males in UBB conditions. The results of this work contribute to the body of research concerning high-rate axial loading of the lower extremity and form the first detailed biomechanical account of UBB effects on female PMHS. This work will inform future decisions regarding the requirements for a valid injury assessment capability for female Warfighters in the UBB environment and the subsequent research needed to support those requirements. Ultimately, advancements can be made in modeling and simulation capabilities, injury assessment criteria, test methodologies, and design approaches for safer military ground vehicles and personal protective equipment (PPE). Improvements in these technologies will reduce morbidity and mortality rates among the U.S. Warfighter population, both male and female. / During an under-body blast (UBB) event, an improvised explosive device (IED) delivers a high-energy blast beneath a military vehicle. Energy from the explosive is imparted to the occupants primarily through the floor and seats of the vehicle, exposing the occupants to considerable risk of injuries to the lower extremity. Compared to civilian automotive crashes, the lower extremities of occupants in UBB scenarios are exposed to greater forces, applied at higher rates, and in different locations and directions. To improve current vehicle systems and personal protective equipment (PPE), it is crucial to develop tools to evaluate injuries in UBB scenarios. One such tool is a test dummy, which is designed to quantify loads, deflections, and accelerations experienced by occupants during a crash. These measured values are compared to accepted thresholds, above which injury is likely to occur. The Warrior Injury Assessment Manikin (WIAMan), which is representative of the 50th-percentile male, is the only test dummy designed to evaluate injuries in UBB conditions. However, there are no known injury assessment tools for the female Warfighter at this time. The overarching goal of this research effort is to determine the origin of potential differences in the response of females and males in UBB conditions. The results of this work contribute to the body of research concerning high-rate axial loading of the lower extremity and form the first detailed biomechanical account of UBB effects on female post-mortem human surrogates (PMHS). The results will inform the development of injury assessment tools for female Warfighters, which will ultimately lead to improvements in technologies to reduce morbidity and mortality rates among the U.S. Warfighter population, both male and female.

Every year, over 3.5 million women give birth in the United States, with about 67.9% delivering vaginally. Over 80% of postpartum (PP) women experience chronic pain in the pelvis, lower back, hip, and legs at 24 weeks after birth, and 20% continue to experience these issues 3 years later. PP women often face pelvic instability and weakness, which disturb balance and lead to asymmetric loading in the pelvis and legs. This imbalance makes daily tasks, such as lifting and carrying a car seat during childcare, more difficult, and increases the risk of chronic pain and injury. This study aimed to explore how different groups – PP and nulliparous (NP) women – and different ways of holding a car seat while standing – no holding, symmetrical holding with two hands in front, and asymmetrical holding with one arm by the side – affect balance and limb loading symmetry. Results showed that postpartum women struggled more with balance as the task became more challenging, with asymmetrical holding showing large differences between groups. PP women also exhibited greater asymmetric limb loading compared to NP women with asymmetrical holding creating the greatest level of asymmetric limb loading. The study also aimed to explore how the two groups – PP and NP – and the different ways of lifting a car seat – symmetrically and asymmetrically – affect balance and limb loading. Both groups had more asymmetric limb loading and worse balance with asymmetrical lifting, though NP women showed larger movements during asymmetrical lifting, likely reflecting the movement of the body during the condition. These results highlight the importance to further research balance and limb loading in PP compared to NP women. Understanding whether pelvic instability and weakness may contribute to differences in balance and limb loading is crucial as it may help explain how and why postpartum women face higher risk of injury and chronic pain. Ultimately, such work may find ways to improve postpartum health during daily activities. / VT Engineering Faculty Organization-Opportunity (EFO-O) Seed Investment / Master of Science / Every year, over 3.5 million women give birth in the United States, with about 67.9% delivering vaginally. Over 80% of postpartum (PP) women experience chronic pain in the pelvis, lower back, hip, and legs at 24 weeks after birth, and 20% continue to experience these issues 3 years later. PP women often face pelvic instability and weakness, which disturb balance and lead to asymmetric loading in the pelvis and legs. This imbalance makes daily tasks, such as lifting and carrying a car seat during childcare, more difficult, and increase the risk of chronic pain and injury. This study aimed to explore how different groups – PP and nulliparous (NP) women – and different ways of holding a car seat while standing – no holding, symmetrical holding with two hands in front, and asymmetrical holding with one arm by the side – affect balance and limb loading symmetry. Results showed that postpartum women struggled more with balance as the task became more challenging, with asymmetrical holding showing large differences between groups. PP women also exhibited greater asymmetric limb loading compared to NP women with asymmetrical holding creating the greatest level asymmetric limb loading. The study also aimed to explore how the two groups – PP and NP – and the different ways of lifting a car seat – symmetrically and asymmetrically – affect balance and limb loading. Both groups had more asymmetric limb loading and worse balance with asymmetrical lifting, though NP women showed larger movements during asymmetrical lifting, likely reflecting the movement of the body during the condition. These results highlight the importance to further research balance and limb loading in PP compared to NP women. Understanding whether pelvic instability and weakness may contribute to differences in balance and limb loading is crucial as it may help explain how and why postpartum women face higher risk of injury and chronic pain. Ultimately, such work may find ways to improve postpartum health during daily activities.

Introduction Bypass surgery for infrainguinal disease is indicated when a patient presents with chronic (disabling claudication or chronic limb-threatening ischaemia) or acute ischemia. Duplex ultrasound surveillance can be used in the follow-up period to detect grafts in risk of failure. If detected before occlusion occurs an intervention can prolong patency. Aim The purpose of this study was to evaluate the outcome of the procedure, whether there are factors associated with no improvement, and to elucidate the value of routine ultrasound surveillance. Methods Patients who underwent lower extremity bypass surgery at Falu hospital between 2010 and 2020 were identified from the national registry Swedvasc. Clinical outcome was based on change in the Rutherford classification. Duplex ultrasound measured peak systolic velocities. A significant stenosis was defined as a 2-3.5-fold increase in ratio of adjacent velocities in the bypass. For a non-significant stenosis, the ratio had to be increased but by less than 2 times. Results 114 patients underwent bypass surgery. Mean age was 70 years. Postoperative surveillance was carried out for 78 patients. Of these, 40 (51.3%) presented with an abnormality and further 30 of them (75%) received further intervention. There was a correlation between cardiac risk and outcome at the 30-day follow-up. For the majority of the not-surveilled, a major adverse event occurred within 1 year. Conclusions Bypass surgery was beneficial for the majority. Cardiac risk was a negative predictor for outcome. Most patients attending the surveillance benefited from early detection of risk of graft failure. To improve its value and efficacy, guidelines are needed within the clinic.