INTRODUCTION: Muscle activity and timing of the swing phases may contribute to the differences we see in athletes at different skill levels. The purpose of this study is to analyze the differences between mean muscle activity, peak muscle active and time to peak muscle activity for select muscles in the lower extremity as well as the differences between start times for swing phases and bat velocity prior to impact for a skilled and recreational group. METHODS: Twelve healthy subjects were split into two groups based on competitive level and analyzed hitting off of a tee. RESULTS: No significant differences were seen between muscle activity or the start time for the landing and swinging between groups. The skilled group did have a faster time to peak muscle activation for the front leg biceps femoris (p = 0.024), start the shifting (p = 0.12) and stepping (p = 0.11) phases significantly earlier as well as had a higher bat velocity prior to ball contact (p = 0.42) than the recreational group. CONCLUSION: Mean and peak muscle activity trends to be lower for skilled hitters than recreational hitters. Evidence of the skilled group starting the shifting and stepping phase earlier as well as having a higher bat velocity prior to impact could be important in separating hitters into skill level.

The purpose of this study was to establish a motion pattern by characterizing the kinetics and kinematics associated with the hip, knee and ankle joint of a group of healthy yoga teachers when performing three yoga postures and comparing them to three activities of daily living (ADL). A group of experienced female yoga practitioners (n = 13), with a minimum of 5 years teaching experience, between the ages of 20 to 45, performed the Lunge, Warrior II, and Triangle poses starting from Downward Dog. The kinetic and kinematic data of the yoga practitioners was collected when performing yoga postures. The step length, joint angles, range of motion (ROM), joint moments, and angular impulse in sagittal and frontal plane were studied for the hip, knee and ankle during performance. The data were averaged, descriptive statistics of the measures were obtained, and results for each posture as well as for the average yoga practice were presented in tables and figures with standard deviation. The percentages of change and effect sizes were calculated to compare yoga movements to ADL. The stride lengths were similar in the Lunge (1.98m), Warrior II (1.51m), and Triangle (1.43m). The motion patterns of the Lunge and the Warrior II poses follow similar joint angle and joint moment, and angular impulse patterns, whereas the Triangle pose creates distinctly different patterns in most joints and planes. In the Lunge and Warrior II poses, the knee joint reaches a maximal flexion angle of 73.76° and 67.69° respectively, 18% to 32% less than what is classically instructed in a yoga class. The knee reached 9.5° of extension while in Triangle pose. The hip contributed 50-70% of the angular impulse in the lower limb in all three yoga movements. When comparing to ADL, ROM was only greater in the hip in of sagittal plane motion and in the knee if frontal plane motion, and most of the joint moments of the lower extremity were notably smaller in ADL for the minimal values and notably larger for the maximal values in yoga. In conclusion, this is first time to establish the kinematics and kinetics motion patterns of three yoga movement which become a basis for further studying yoga biomechanics and its application. Moreover the motion pattern data suggests that yoga experts do not yoga as practice the Lunge and Warrior poses as classically described in yoga book for the knee and Triangle pose may place the knee in a precarious alignment. Yoga has high demanding to hip strength and ROM, which may help to improve hip strength and subsequently benefit to dynamic stability in gait.

<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.

No description available.

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

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.