Spinal joint moment prediction following simulated breast surgery using a female whole-body musculoskeletal model.

This study aimed to use a musculoskeletal model to predict changes in spinal moments following simulated breast surgery. A female full body musculoskeletal model with a fully articulated thoracolumbar spine and independent moveable breast segments was customised for this study. Key findings suggest that the simulated removal of breast tissue (750 g to 1501 g) can reduce the magnitude of lumbar spine extensor moments by >0.05 Nm/kg during walking and jogging. A customised female whole-body musculoskeletal model is capable of providing a first approximation of changes in spinal loading following simulated breast surgery.

A Global Systematic Review of Lead (Pb) Exposure and its Health Effects in Wild Mammals.

Lead (Pb) is a toxic nonessential metal, known mainly for causing poisoning of humans and wild birds. However, little is known about Pb exposure and its associated health effects in wild mammals. We conducted a global systematic literature review to identify peer-reviewed studies published on Pb exposure in wild mammalian species and the health effects they identified. In total, 183 studies, conducted in 35 countries and published over 62 yr (1961-2022), were included in the review. Only 6% (11/183) of the studies were conducted in developing countries. Although 153 mammalian species were studied, most studies focused on species that are easy to access (i.e., hunted species and small mammals that are easy to trap). Therefore, carnivores and scavengers were less frequently studied than herbivores and omnivores. Despite all studies reporting Pb concentrations, only 45 (25%) studies investigated health effects and, of these 45 studies, only 28 (62%) found any health effect in 57 species. All health effects were negative and ranged from subclinical effects to fatality. Methodologies of Pb sampling and quantification and reporting of results varied widely across the studies, making both Pb concentrations and health effects difficult to compare and evaluate. Thus, there is a need for more research on Pb exposure and its health effects on wild mammals, especially as carnivores and scavengers could be used as sentinels for ecosystem health.

A retained foreign body in a jejunal diverticulum.

Retained foreign bodies in small bowel diverticula are a rare occurrence. Batteries and battery containing products can cause bowel perforation, and when retained in diverticula, retrieval methods may need to be considered. We present a novel case of a hearing aid powered by lithium battery getting stuck in a jejunal diverticulum, and outline an approach to retrieval.

A Cross-Sectional Analysis of Products Marketed as Plant-Based Across the United States, United Kingdom, and Canada Using Online Nutrition Information.

Background: The food industry is responding to a rising demand for plant-based foods by developing and marketing an ever-wider range of vegan and vegetarian products under the banner of "plant-based." Understanding the nutritional properties of these products is critical. Objectives: To assess the number, meal type, and nutritional content of products marketed as plant-based (MaPB) from the perspective of the consumer across multiple sectors in the United States, United Kingdom, and Canada. Methods: An online search for products MaPB was performed across supermarkets, restaurants, food manufacturers, and plant-based meal delivery companies in the United Kingdom, the United States, and Canada using the terms: "vegan," "vegetarian," and "plant-based." Online nutrition data were extracted, and whole meals that comprised >50% of ingredients such as fruits, vegetables, legumes, nuts, and seeds were identified. The nutritional content of dishes MaPB in restaurants was also directly compared with meat-containing dishes. Results: Further, 3488 unique products were identified, of which 962 were whole meals and 1137 were a replacement for the main protein component in a meal, including 771 meat alternatives. Across all sectors, 45% of whole meals had >15-g protein, 70% had <10% kcal from saturated fat; 29% had >10-g fiber per meal, and 86% had <1000 mg sodium. At restaurants, 1507 meat-containing dishes were identified and compared with 191 vegetarian and 81 vegan dishes. The meat-containing dishes were higher in protein [35.4 g (24.0-51.4)] compared with vegetarian [19.0 g (13.0-26.1)] and vegan [16.2 g (10.5-23.2) dishes (P < 0.001)]. The vegan dishes were low in saturated fat and sodium (SFA: 6.3 g ± 6.4, Sodium: 800 mg (545.0-1410.0) compared with both meat [SFA: 11.6 g ± 10.0; Sodium: 1280 mg (820.0-1952.0)] and vegetarian [SFA: 9.4 g ± 7.6; Sodium: 1011 mg (603.0-1560.0)] options (P < 0.001 for all comparisons). Conclusions: Products MaPB tend to have lower concentrations of saturated fat and sodium than their meat-containing counterparts, but improvements are needed to optimize their nutritional composition.

The visual control of locomotion when stepping onto moving surfaces: A comparison of younger and older adults.

Stepping between static and moving surfaces presents a locomotor challenge associated with increased injury frequency and severity in older adults. The current study evaluates younger and older adults' behaviours when overcoming challenges sampling moving walkway and escalator environments. Twelve younger adults (18-40 years, Male = 8) and 15 older adults (60-81 years, Male = 5) were examined using an integration of optoelectronic motion capture and mobile eye-tracking. Participants were investigated approaching and stepping onto a flat conveyor belt (static or moving; with or without surface (demarcation) lines). Specifically, the four conditions were: (i) static surface without demarcation lines; (ii) static surface with demarcation lines; (iii) moving surface without demarcation lines; and (iv) moving surface with demarcation lines. A two (age group) x two (surface-condition) x two (demarcation-condition) linear mixed-model revealed no main or interaction effects (p > .05) for perturbation magnitude, indicating participants maintained successful locomotion. However, different adaptive behaviours were identified between conditions with moving and accuracy demands (e.g., moving surfaces increased step length, demarcations reduced step length). Between subject effects identified differences between age groups. Older adults utilised different behaviours, such as earlier gaze transfer from the final approach walkway step location. Overall, the current study suggests that adaptive behaviours emerge relative to the environment's specific demands and the individual's action capabilities.

Calibration methods for flow rates down to 5 nL/min and validation methodology.

Improving the accuracy and enabling traceable measurements of volume, flow, and pressure in existing drug delivery devices and in-line sensors operating at very low flow rates is essential in several fields of activities and specially in medical applications. This can only be achieved through the development of new calibrationmethods and by expanding the existing metrological infrastructure to perform micro-flow and nano-flow measurements. In this paper, we will investigate new traceable techniques for measuring flow rate, from 5 nL/min to 1,500 nL/min and present the results of an inter-comparison between nine laboratories for the calibration of two different flow meters and a syringe pump.

Evaluating the integration of eye-tracking and motion capture technologies: Quantifying the accuracy and precision of gaze measures.

Integrating mobile eye tracking and optoelectronic motion capture enables point of gaze to be expressed within the laboratory co-ordinate system and presents a method not commonly applied during research examining dynamic behaviors, such as locomotion. This paper examines the quality of gaze data collected through the integration. Based on research suggesting increased viewing distances are associated with reduced data quality; the accuracy and precision of gaze data as participants (N = 11) viewed floor-based targets at distances of 1-6 m was investigated. A mean accuracy of 2.55 ± 1.12° was identified, however, accuracy and precision measures (relative to targets) were significantly (p < .05) reduced at greater viewing distances. We then consider if signal processing techniques may improve accuracy and precision, and overcome issues associated with missing data. A 4th-order Butterworth lowpass filter with cut-off frequencies determined via autocorrelation did not significantly improve data quality, however, interpolation via Quintic spline was sufficient to overcome gaps of up to 0.1 s. We conclude the integration of gaze and motion capture presents a viable methodology in the study of human behavior and presents advantages for data collection, treatment, and analysis. We provide considerations for the collection, analysis, and treatment of gaze data that may help inform future methodological decisions.

Can we predict the neutral breast position using the gravity-loaded breast position, age, anthropometrics and breast composition data?

BACKGROUND: This study aimed to identify the predictor variables which account for neutral breast position variance using a full independent variable dataset (the gravity-loaded breast position, age and anthropometrics, and magnetic resonance imaging breast composition data), and a simplified independent variable dataset (magnetic resonance imaging breast composition data excluded). METHODS: Breast position (three-dimensional neutral and static gravity-loaded), age, anthropometrics and magnetic resonance imaging breast composition data were collected for 80 females (bra size 32A to 38D). Correlations between the neutral breast position and the gravity-loaded breast position, age, anthropometrics, and magnetic resonance imaging breast composition data were assessed. Multiple linear and multivariate multiple regression models were utilised to predict neutral breast positions, with mean absolute differences and root mean square error comparing observed and predicted neutral breast positions. FINDINGS: Breast volume was the only breast composition variable to contribute as a predictor of the neutral breast position. While ≥69% of the variance in the anteroposterior and mediolateral neutral breast positions were accounted for utilising the gravity-loaded breast position, multivariate multiple regression modelling resulted in mean absolute differences >5 mm. INTERPRETATION: Due to the marginal contribution of breast composition data, a full independent variable dataset may be unnecessary for this application. Additionally, the gravity-loaded breast position, age, anthropometrics, and breast composition data do not successfully predict the neutral breast position. Incorporation of the neutral breast position into breast support garments may enhance bra development. However, further identification of variables which predict the neutral breast position is required.

There are two sides to every story: implications of asymmetry on breast support requirements for sports bra manufacturers.

This study aimed to investigate: (1) the prevalence and magnitude of breast movement asymmetry, (2) the interaction between static and dynamic breast asymmetry and (3) the influence of sports bras on breast asymmetry during running. Position data were collected from 167 females whilst treadmill running and then a sub-group of 12 participants in different bra conditions. Breast movement asymmetry existed in 89% of participants, with resultant static breast position asymmetry larger in participants displaying dynamic asymmetry. Asymmetry was most commonly caused (60% to 75%) by greater movement of the left breast. No significant relationships were found between asymmetry and bra size or breast pain. Sports bras reduced asymmetry prevalence from 75% to 33% of participants in the antero-posterior direction but only from 75% to 67% of participants in the infero-superior direction. The magnitude of range-of-motion asymmetry reduced from 67 mm with no bra to between 6 and 64 mm in-bra in the infero-superior direction, with the best performing bra incorporating encapsulating cups and adjustable straps and underband. It is recommended that sports bras allow underband and strap adjustment to facilitate individual breast support and that asymmetry is considered when designing and fitting bras, which could utilise resultant asymmetry measured statically.

SIRT Compared with DEB-TACE for Hepatocellular Carcinoma: a Real-world Study (the SITAR Study).

BACKGROUND: Hepatocellular carcinoma (HCC) is responsible for 1% of deaths worldwide, and the incidence continues to increase. Despite surveillance programs, 70% of HCC patients are not suitable for curative options at diagnosis, and therefore, non-curative treatments are essential to modern clinical practice. There are many novel treatments, though their roles are not well defined. This study aimed to contrast Selective Internal Radiation Therapy (SIRT) and Drug Eluting Bead Transarterial Chemoembolisation (DEB-TACE) to further define their roles. METHODS: This was a retrospective multicentre cohort study. Factors included for analysis were type of HCC treatment, number of lesions, lesion size, multiple disease severity scores, cirrhosis and vascular invasion. The primary endpoint was transplant-free survival. RESULTS: Transplant-free survival was similar between the two cohorts (p = 0.654), despite a variation in median lesion size, SIRT: 54.5 mm, DEB-TACE: 34 mm (p ≤ 0.001). A univariate Cox proportional hazard model utilising treatment modality as the covariate showed no significant difference in survival (DEB-TACE HR 1.4 (95%CI 0.85-2.15 p = 0.207). The size of the largest lesion was the best predictor of 3-year survival (p = 0.035). Lesion size was inversely associated with survival (HR 1.01 (95%CI 1-1.02, p = 0.025)) on multivariate analysis. CONCLUSION: This study is the first to catalogue the experience of using SIRT in HCC in a real-world Australian population. It has demonstrated no difference in survival outcomes between DEB-TACE and SIRT. Further, it has shown SIRT to be a reasonable alternative to DEB-TACE especially in larger lesions and has demonstrated that DEB-TACE has a role in select patients with advanced disease.

A novel multi-study intervention investigating the short and long term effects of a posture bra on whole body and breast kinematics.

BACKGROUND: Poor standing posture has been reported in women with larger breasts, increasing the risk of back pain. Whilst breast reduction surgery can improve posture, conservative measures such as special bras may offer short or long-term relief of symptoms without surgical intervention. RESEARCH QUESTION: This study aimed to utilise a multi-study intervention to investigate the short and long-term kinematic effects of wearing a posture bra. METHODS: Study one utilised biomechanics and physiotherapy expertise to modify the design of a prototype bra to improve posture and breast kinematics; resulting in a second-generation posture bra. To test this bra, 24 females were randomly assigned to control and intervention groups. The control group wore their everyday bra; the intervention group wore the generation 2 posture bra in place of their everyday bra for three months. Pre and post intervention, posture (spine curvature, scapula position, whole body alignment) and breast kinematics were assessed during sitting, standing and walking. Short-term effects of the posture bra were compared to an everyday bra and no bra (study two), whilst the long-term effects were compared using the no bra condition (study three). RESULTS: Biomechanical intervention improved posture and breast kinematics in a prototype posture bra resulting in a second-generation prototype. Pre-intervention, the generation 2 posture bra significantly improved scapula retraction by 6° during both sitting and standing, but also increased deviation of whole body alignment compared to everyday bra and no bra conditions. During walking the posture bra reduced breast motion by 17 % compared to the everyday bra. Following the three-month wearer intervention, scapula depression significantly improved in the intervention group. SIGNIFICANCE: A biomechanically informed posture bra was able to effectively support the breasts and improve scapula position without compromising spinal curvature, reducing the risk of musculoskeletal pain associated with poor posture.

Do static and dynamic activities induce potentially damaging breast skin strain?

BACKGROUND/AIM: This study aimed to quantify breast skin strain and strain rate and the effect of support garments at reducing strain and to determine characteristics that correlate with strain during static and dynamic activity. METHODS: 39 women (UK size 32C to 36G) had electromagnetic sensors applied to their breast skin. Sensor coordinates were recorded while standing, walking, running, in no, low and high breast support conditions, plus bare-breasted in the estimated neutral position to calculate strain. Relative breast coordinates and 35 inter-sensor distances identified peak breast skin strain (%) and strain rate (%·s-1), which were then correlated with nipple kinematics, breast pain and participant characteristics. RESULTS: Mean peak breast skin strain was generally <60% during standing, walking and running; however, some individuals exhibited 93% strain in bare-breasted running. Compared with low support, high support did not further reduce strain during standing and walking. Peak breast skin strain/strain rate location was longitudinal, in lateral and medial breast regions and displayed strong correlations with breast volume, body mass index and bust circumference. CONCLUSION: Static and dynamic activity did not result in excessive breast skin strain, suggesting low risk of skin damage. However, during running, some individuals experienced excessive skin strains (up to 93%) and strain rates (up to 1258%·s-1). Breast skin strain/strain rate location suggests lift is required in the lateral and medial bra cup to reduce strain, particularly in larger breast volumes due to increased skin strain risk.

The Effects of Compression Garments on Stability and Lower Limb Kinematics During a Forward Lunge.

Compression garments have been used to minimise injury risk, through improvements in stability and joint positioning; yet, it is unclear whether there is an optimal length or tightness of these garments that may maximise observed benefits. This study measured the effect of three different garment types, at two different tightness levels, on lower extremity stability and alignment during a forward lunge movement. Sixteen healthy adults (7 female, 9 male; 24.3 ± 2.9 years) were recruited as participants. Stability of the lead foot, as well as lower body joint kinematics, were recorded using an Oqus 12-camera system, surrounding participants as they executed three forward lunges onto a Matscan pressure mat under seven compression conditions (Control, Light/Heavy Calf, Light/Heavy Socks, Light/Heavy Leggings). Mean minimum time-to-boundary (mmTtB) (derived from centre of pressure measures) and frontal plane kinematics (lateral pelvic tilt, knee valgus, ankle inversion/eversion) were used to assess the effect of garment tightness and length on lunge stability and joint alignment, respectively. A significant effect of tightness on mmTtB was observed (F(1,105) = 8.192; p = .005, η2 = .072), with Heavy garments eliciting longer mmTtB compared to their corresponding Light (-.18 ± .06 s; p = .015) or Control (-.28 ± .09 s; p = .007) conditions. No significant effects of garment tightness or length on lower body kinematics were evident. The results of this study suggest stability during a forward lunge is improved through the use of tight-fitted compression garments.

The Kinematics of Breasts Implanted With a Reduced Mass Implant: A Pilot Study.

BACKGROUND: Breast implants may increase breast skin tension and interact with surrounding tissues to alter breast position and motion during dynamic activity. Reducing implant mass and changing implant location (submuscular/subglandular) may also affect breast kinematics and the subsequent loads on breast structures. OBJECTIVES: The aim of this pilot study was to describe the kinematics of breasts augmented with reduced-mass implants during standing, walking, and running, compared with natural breasts, and to provide insight into how implant location (submuscular/subglandular) alters breast kinematics. METHODS: Two breast augmentation participants (12-15 months postsurgery: 32AA presurgery, anatomical submuscular 255 cc B-Lite reduced-mass implant; 32A presurgery, anatomical subglandular 285 cc B-Lite reduced-mass implant) and 2 natural-breasted participants of similar breast size and anthropometrics were recruited. Nipple and torso positional data were recorded with electromagnetic sensors during standing, walking, and running. Nipple kinematics relative to the torso were calculated. RESULTS: The B-Lite participants both displayed greater nipple projection and elevation during standing and a 50% reduction in nipple acceleration during walking, when compared with their natural counterparts. During running, the B-Lite subglandular participant displayed decreased nipple kinematics compared with her natural counterpart and lower nipple kinematics compared with the B-Lite submuscular participant during walking and running. CONCLUSIONS: A combination of implant location (subglandular) and reduced mass minimized nipple kinematics during running. Reducing nipple kinematics during dynamic activity may decrease the loading on breast structures, helping to decrease ptosis and increase the longevity of procedure outcomes.

Continuous terlipressin infusion is associated with improved diet intake and muscle strength in patients awaiting liver transplant.

BACKGROUND & AIMS: Portal hypertension contributes to the pathogenesis of malnutrition and sarcopenia in cirrhosis via multiple mechanisms. Terlipressin is a vasopressin analogue that we administer via continuous outpatient infusion, as a bridge to transplantation in patients with hepatorenal syndrome or refractory ascites. We describe, for the first time, the impact of outpatient terlipressin on nutritional and muscle parameters. METHODS: Nutrition (subjective global assessment), handgrip strength, dietary intake (energy, protein), frequency of paracentesis and severity of liver disease (model for end-stage liver disease score) were prospectively recorded at terlipressin commencement and follow-up (transplantation, cessation or census date). RESULTS: Nineteen patients were included (89% male, median age 59.6 years, median model for end-stage liver disease score 24), of whom 12 had hepatorenal syndrome and 7 had refractory ascites. All patients were malnourished at baseline, 63% (n = 12) had sarcopenic-range grip strength, and mean paracentesis frequency was 2.86 ± 1.62/month. Median duration of terlipressin was 51 days (interquartile range 29-222). Fourteen patients (74%) were transplanted, 2 delisted (10%) and 3 (16%) continued terlipressin. Energy and protein intake improved significantly following terlipressin, from 17.94 ± 5.43 kcal/kg to 27.70 ± 7.48 kcal/kg, and 0.74 ± 0.28 g/kg to 1.16 ± 0.31 g/kg, respectively (both p < 0.001). Handgrip strength increased from 25.36 ± 8.13 kg to 28.49 ± 7.63 kg (p = 0.001). Linear regression analysis demonstrated hand grip strength increased 0.075% for every 1-day of terlipressin (p = 0.005). The frequency of large-volume paracentesis reduced by 46%, to 1.57 ± 1.51/month (p = 0.001). CONCLUSION: Continuous terlipressin infusion reduces the complications of portal hypertension and is associated with an improvement in nutritional and muscle parameters in patients on the liver transplant waiting list, in whom such characteristics usually demonstrate progressive decline. This validates both the aetiological role of portal hypertension in malnutrition and represents a promising new anabolic therapy. LAY SUMMARY: Malnutrition and poor muscle strength are common in liver disease and often get worse while patients await liver transplant. Terlipressin is a medication used to treat portal hypertension in patients with hepatorenal syndrome. It is usually given for a few days or weeks in patients confined to hospital. Our centre provides outpatient terlipressin for weeks to months as a bridge to liver transplant. In patients treated with terlipressin at our hospital, we observed a substantial increase in their dietary intake and muscle strength, which may improve their quality of life and outcomes after liver transplant.

Quantification of gravity-induced skin strain across the breast surface.

BACKGROUND: Quantification of the magnitude of skin strain in different regions of the breast may help to estimate possible gravity-induced damage whilst also being able to inform the selection of incision locations during breast surgery. The aim of this study was to quantify static skin strain over the breast surface and to estimate the risk of skin damage caused by gravitational loading. METHODS: Fourteen participants had 21 markers applied to their torso and left breast. The non-gravity breast position was estimated as the mid-point of the breast positions in water and soybean oil (higher and lower density than breast respectively). The static gravity-loaded breast position was also measured. Skin strain was calculated as the percentage extension between adjacent breast markers in the gravity and non-gravity loaded conditions. FINDINGS: Gravity induced breast deformation caused peak strains ranging from 14 to 75% across participants, with potentially damaging skin strain (>60%) in one participant and skin strains above 30% (skin resistance zone) in a further four participants. These peak strain values all occurred in the longitudinal direction in the upper region of the breast skin. In the latitudinal direction, smaller-breasted participants experienced greater strain on the outer (lateral) breast regions and less strain on the inner (medial) breast regions, a trend which was reversed in the larger breasted participants (above size 34D). INTERPRETATION: To reduce tension on surgical incisions it is suggested that preference should be given to medial latitudinal locations for smaller breasted women and lateral latitudinal locations for larger breasted women.

Evidence of Big Five and Aggressive Personalities in Gait Biomechanics.

Behavioral observation techniques which relate action to personality have long been neglected (Furr and Funder in Handbook of research methods in personality psychology, The Guilford Press, New York, 2007) and, when employed, often use human judges to code behavior. In the current study we used an alternative to human coding (biomechanical research techniques) to investigate how personality traits are manifest in gait. We used motion capture technology to record 29 participants walking on a treadmill at their natural speed. We analyzed their thorax and pelvis movements, as well as speed of gait. Participants completed personality questionnaires, including a Big Five measure and a trait aggression questionnaire. We found that gait related to several of our personality measures. The magnitude of upper body movement, lower body movement, and walking speed, were related to Big Five personality traits and aggression. Here, we present evidence that some gait measures can relate to Big Five and aggressive personalities. We know of no other examples of research where gait has been shown to correlate with self-reported measures of personality and suggest that more research should be conducted between largely automatic movement and personality.

Estimating the gravity induced three dimensional deformation of the breast.

As human breast tissue is continuously deformed by gravity, it is difficult to identify the non-loaded neutral breast position from which to take measurements. To estimate the neutral nipple position, this study proposed a simple novel method to counteract the three dimensional effect of gravity on the breast using the buoyant forces from water and soybean oil (ρWATER = 994kgm-3; ρOIL = 909kgm-3). Fourteen female participants with breast sizes ranging from 30 to 34in. under band and B to E cup size took part in this study. Each participant had their static gravity-loaded nipple position measured and their neutral nipple position estimated (as the midpoint between the nipple position during water and soybean oil immersion). Participants were asked to sit in each fluid and fully submerge their torso and breasts. The mean gravity-induced nipple displacements from the neutral nipple position were 15.3mm in the posterior direction, 7.4mm in the lateral direction, and 25.7mm in the inferior direction. Gravity had a significant (p < 0.05, r > 0.82) measurable effect on the static nipple position, particularly in the inferior and posterior directions. Furthermore the density difference between water and soybean oil produced a significant difference (p < 0.05, r = 0.72) in superior-inferior nipple position (5.6mm). These findings suggest that neglect of gravity-induced breast deformations may lead to errors when assessing breast position and its relationship to possible breast pain, and that water alone may not be sufficient to estimate the neutral nipple position.