Trastuzumab deruxtecan in previously treated HER2-positive metastatic or unresectable breast cancer: Real-life data from the temporary use authorization program in France.

BACKGROUND: Early access program (formerly cohort Temporary Authorization for Use) was granted for trastuzumab deruxtecan (T-DXd) in France based on DESTINY-Breast01 trial which demonstrated its efficacy and safety in HER2-positive metastatic/unresectable breast cancer after ≥2 anti-HER2-based regimens received at metastatic stage. METHODS: This multicenter real-world early access program included HER2-positive metastatic/unresectable breast patients pretreated with at least two lines of anti-HER2 regimens who received T-DXd 5.4 mg/kg intravenously in monotherapy every 3 weeks. RESULTS: Four hundred and fifty-nine patients (median age, 58 years; hormone receptor-positive, 67%; brain metastases, 28.1%) received T-DXd. Before inclusion, 81.7% of patients had radiation therapy and 76.5% had undergone surgery. Median number of prior metastatic treatment lines was four (range, 2-22); 99.8% patients had received trastuzumab, 94.8% trastuzumab emtansine and 79.3% pertuzumab. Follow-up was performed from September 30, 2020 to March 30, 2021; when the early access program stopped, the median duration of T-DXd treatment was 3.4 (range, 0-7.8) months. In 160 patients with available tumor assessment, objective response rate was 56.7% and 12.1% had progression. In 57 patients with available brain tumor assessment, complete or partial intracranial response was reported for 35.7% patients and 5.4% had progression. A total of 17 (3.7%) patients with interstitial lung disease (ILD) was reported with no cases of ILD-related death. CONCLUSIONS: In this early access program in patients with heavily pretreated HER2-positive metastatic/unresectable breast cancer, T-DXd had antitumor activity with a similar response to that reported in previous clinical studies. T-DXd was well tolerated and no new safety signals were observed.

Characterization of HER2-low breast cancer in young women with germline BRCA1/2 pathogenetic variants: Results of a large international retrospective cohort study.

BACKGROUND: Breast cancer (BC) in women aged ≤40 years carrying germline pathogenetic variants (PVs) in BRCA1/2 genes is infrequent but often associated with aggressive features. Human epidermal growth factor receptor 2 (HER2)-low-expressing BC has recently emerged as a novel therapeutic target but has not been characterized in this rare patient subset. METHODS: Women aged ≤40 years with newly diagnosed early-stage HER2-negative BC (HER2-0 and HER2-low) and germline BRCA1/2 PVs from 78 health care centers worldwide were retrospectively included. Chi-square test and Student t-test were used to describe variable distribution between HER2-0 and HER2-low. Associations with HER2-low status were assessed with logistic regression. Kaplan-Meier method and Cox regression analysis were used to assess disease-free survival (DFS) and overall survival. Statistical significance was considered for p ≤ .05. RESULTS: Of 3547 included patients, 32.3% had HER2-low BC, representing 46.3% of hormone receptor-positive and 21.3% of triple-negative (TN) tumors. HER2-low vs. HER2-0 BC were more often of grade 1/2 (p < .001), hormone receptor-positive (p < .001), and node-positive (p = .003). BRCA2 PVs were more often associated with HER2-low than BRCA1 PVs (p < .001). HER2-low versus HER2-0 showed better DFS (hazard ratio [HR], 0.86; 95% CI, 0.76-0.97) in the overall population and more favorable DFS (HR, 0.78; 95% CI, 0.64-0.95) and overall survival (HR, 0.65; 95% CI, 0.46-0.93) in the TN subgroup. Luminal A-like tumors in HER2-low (p = .014) and TN and luminal A-like in HER2-0 (p = .019) showed the worst DFS. CONCLUSIONS: In young patients with HER2-negative BC and germline BRCA1/2 PVs, HER2-low disease was less frequent than expected and more frequently linked to BRCA2 PVs and associated with luminal-like disease. HER2-low status was associated with a modestly improved prognosis.

Dynamic Projection of Medication Nonpersistence and Nonadherence Among Patients With Early Breast Cancer.

Importance: Oral endocrine treatments have been shown to be effective when carefully adhered to. However, in patients with early breast cancer, adherence challenges are notable, with 17% experiencing nonpersistence and 41% nonadherence at least once. Objective: To model the persistence of and adherence to oral anticancer treatment of a patient with localized breast cancer. Design, Setting, and Participants: This cohort study was conducted using anonymous reimbursement data belonging to French female patients with breast cancer, extracted from the French Health Insurance database from January 2013 to December 2018. Data analysis was conducted from January 2021 to May 2022. Main Outcomes and Measures: The main outcome was the detection of episodes of nonpersistence and nonadherence 6 months before they happened. Adherence was defined as the ratio between the time covered by a drug purchase and the time between 2 purchases; patients were considered nonadherent if the ratio of their next 3 purchases was less than 80%. Disparities in persistence and adherence based on criteria such as age, treatment type, and income were identified. Results: A total of 229 695 female patients (median [IQR] age, 63 [52-72] years) with localized breast cancer were included. A deep learning model based on a gated-recurrent unit architecture was used to detect episodes of nonpersistence or nonadherence. This model demonstrated an area under the receiving operating curve of 0.71 for persistence and 0.73 for adherence. Analyzing the Shapley Additive Explanations values also gave insights into the contribution of the different features over the model's decision. Patients older than 70 years, with past nonadherence, taking more than 1 treatment in the previous 3 months, and with low income had greater risk of episodes of nonpersistence. Age and past nonadherence, including regularity of past adherence, were also important features in the nonadherence model. Conclusions and Relevance: This cohort study found associations of patient age and past adherence with nonpersistence or nonadherence. It also suggested that regular intervals in treatment purchases enhanced adherence, in contrast to irregular purchasing patterns. This research offers valuable tools for improving persistence of and adherence to oral anticancer treatment among patients with early breast cancer.

Validation of the Equidyn protocol for evaluation of dynamic balance in older adults through a smartphone application.

BACKGROUND: Different tasks and proxy measurements have been employed to evaluate dynamic balance in older individuals. However, due to inherent limitations, results from most evaluations could hardly be taken as valid measurements of dynamic balance. RESEARCH QUESTION: Is the Equidyn smartphone application-based protocol valid and sensitive for assessment of dynamic balance in older adults? METHODS: Dynamic balance was evaluated in 52 physically active individuals, age range 60-80 years (M = 69.36). The dynamic tasks were one-leg sway either in the mediolateral (ML) or anteroposterior (AP) direction while supported on the contralateral leg, and cyclic sit-to-stand with a narrow support base. These tasks were performed under standardized movement amplitude and rhythm. Outcomes were correlated with unipedal quiet standing. A smartphone was attached to the trunk backside, and a custom-made application (Equidyn) was employed to provide guidance throughout evaluation, timed beeps to pace the movements, and three-dimensional trunk acceleration measurement for balance evaluation. RESULTS: Our data showed (a) that both ML and AP leg sway tasks were sensitive to aging and to direction of leg sway movements; (b) referenced to quiet unipedal stance, moderate/strong correlations for the ML/AP leg sway tasks and moderate correlations for the sit-to-stand task; and (c) moderate/strong correlations between the ML and AP leg sway tasks, and moderate correlations between the sit-to-stand and the two unipedal dynamic tasks in the ML acceleration direction. SIGNIFICANCE: The current results support the conclusion that the Equidyn protocol is a sensitive and valid tool to evaluate dynamic balance in healthy older individuals. The protocol tasks standardized in amplitude and rhythm favor their reproducibility and trunk acceleration data interpretation. As the whole assessment is made through a smartphone application, this dynamic balance evaluation could be made in a low-cost simple way both in the laboratory and clinical settings.

Nursing assessment and care for a patient with a neurological disorder.

The previous article discussed the pathophysiology involved in disorders of the nervous system. Having considered some of the most prevalent disorders, this second part uses a case study to explore effective patient assessment and emphasise the importance of facilitating patient self-management for improved outcomes. By addressing these key aspects, nursing professionals can enhance the quality of care and the support provided to individuals experiencing neurological disorders.

Symmetric unipedal balance in quiet stance and dynamic tasks in older individuals.

Previous evidence of increased difference of muscular strength between the dominant and non-dominant legs in older adults suggests the possibility of dissimilar balance control between the legs (between-leg asymmetry) associated with aging. In the current investigation, we evaluated between-leg asymmetries in older adults when performing quiet and dynamic balance tasks. Fifty-two physically active and healthy older adults within the age range of 60 to 80 years were recruited. Participants performed balance tasks in unipedal stance, including quiet standing and cyclic sway (rhythmic oscillation) of the non-supporting leg in the anteroposterior or mediolateral directions, producing foot displacements with amplitudes of 20 cm paced in 1 Hz through a metronome. Body balance was evaluated through trunk accelerometry, by using the sensors embedded into a smartphone fixed at the height of the 10th-12th thoracic spines. Analysis revealed lack of significant differences in balance control between the legs either when comparing the right versus left or the preferred versus non-preferred legs, regardless of whether they were performing quiet stance or dynamic tasks. Further examination of the data showed high between-leg correlation coefficients (rs range: 0.71-0.84) across all tasks. Then, our results indicated symmetric and associated between-leg balance control in the examined older adults.

The nervous system and associated disorders.

Disorders of the nervous system, encompassing the brain, spinal cord and peripheral nerves, have emerged as a significant public health issue, with profound implications for individuals worldwide. These conditions result in significant morbidity and mortality. Many patients with neurological disorders often have comorbidities, further complicating their clinical presentation. Therefore, nurses must possess a comprehensive understanding of the nervous system and its associated disorders to formulate detailed care plans that address the unique needs of each patient. This article aims to explore the underlying pathophysiology of some of the most prevalent neurological disorders and how this informs effective patient assessment and diagnostic strategies. A further article will build on this to consider patient assessment and formulating a care plan in more detail.

Mesencephalic Locomotor Region and Presynaptic Inhibition during Anticipatory Postural Adjustments in People with Parkinson's Disease.

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) have a loss of presynaptic inhibition (PSI) during anticipatory postural adjustments (APAs) for step initiation. The mesencephalic locomotor region (MLR) has connections to the reticulospinal tract that mediates inhibitory interneurons responsible for modulating PSI and APAs. Here, we hypothesized that MLR activity during step initiation would explain the loss of PSI during APAs for step initiation in FOG (freezers). Freezers (n = 34) were assessed in the ON-medication state. We assessed the beta of blood oxygenation level-dependent signal change of areas known to initiate and pace gait (e.g., MLR) during a functional magnetic resonance imaging protocol of an APA task. In addition, we assessed the PSI of the soleus muscle during APA for step initiation, and clinical (e.g., disease duration) and behavioral (e.g., FOG severity and APA amplitude for step initiation) variables. A linear multiple regression model showed that MLR activity (R2 = 0.32, p = 0.0006) and APA amplitude (R2 = 0.13, p = 0.0097) explained together 45% of the loss of PSI during step initiation in freezers. Decreased MLR activity during a simulated APA task is related to a higher loss of PSI during APA for step initiation. Deficits in central and spinal inhibitions during APA may be related to FOG pathophysiology.

Access to oncology care in Mali: a qualitative study on breast cancer.

BACKGROUND: Breast cancer is the most common cancer in terms of incidence and mortality among women worldwide, including in Africa, and a rapid increase in the number of new cases of breast cancer has recently been observed in sub-Saharan Africa. Oncology is a relatively new discipline in many West African countries, particularly Mali; thus, little is known about the current state of cancer care infrastructure and oncology practices in these countries. METHODS: To describe the challenges related to access to oncology care in Mali, we used a qualitative approach, following the Consolidated Criteria for Reporting Qualitative Research (COREQ). Thirty-eight semistructured interviews were conducted with health professionals treating cancer in Mali (n = 10), women with breast cancer (n = 25), and representatives of associations (n = 3), and 40 participant observations were conducted in an oncology unit in Bamako. We used the theoretical framework on access to health care developed by Levesque et al. a posteriori to organise and analyse the data collected. RESULTS: Access to oncology care is partly limited by the current state of Mali's health infrastructure (technical platform failures, repeated strikes in university hospitals, incomplete free health care and the unavailability of medicines) and exacerbated by the security crisis that has been occurring the country since 2012. The lack of specialist doctors, combined with limited screening campaigns and a centralised and fragmented technical platform in Bamako, is particularly detrimental to breast cancer treatment. Women's lack of awareness, lack of information throughout the treatment process, stereotypes and opposition to amputations all play a significant role in their ability to seek and access quality care, leading some women to therapeutically wander and others to want to leave Mali. It also leaves them in debt and jeopardises the future of their children. However, the high level of trust in doctors, the involvement of international actors, the level of social support and the growing influence of civil society on the issue of cancer also represent great current opportunities to fight cancer in Mali. CONCLUSION: Despite the efforts of successive Malian governments and the commitment of international actors, the provision of health care is still limited in the country, entrenching global inequalities in women's bodies.

Overall Survival With Circulating Tumor Cell Count-Driven Choice of Therapy in Advanced Breast Cancer: A Randomized Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.In patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer, the STIC CTC trial established that, for choosing between endocrine therapy (ET) or chemotherapy, the use of circulating tumor cell (CTC) count is noninferior to the investigator's choice in terms of progression-free survival. Here, we report overall survival (OS) results, a secondary end point. Patients were randomly assigned in a 1:1 ratio to have their first-line treatment (ET or chemotherapy) determined by investigators or CTC count (chemotherapy if ≥ 5 CTCs/7.5 mL; ET if low CTC count; CellSearch). OS was assessed at the discontinuation of follow-up. After a median follow-up of 4.7 years, 382 deaths (50.6%) had occurred among 755 patients. Median OS was 51.3 months (95% CI, 46.8 to 55.1) in the CTC arm and 45.5 months (95% CI, 40.9 to 51.1) in the standard arm (hazard ratio [HR] for death, 0.85; 95% CI, 0.69 to 1.03; P = .11). Among 189 patients (25.0%) with ET recommended by clinicians and high CTC count, chemotherapy was superior to ET (HR for death, 0.53; 95% CI, 0.36 to 0.78; P = .001). In case of a discordant estimate, OS data demonstrate the clinical utility of CTC count.

Impact of the COVID-19 pandemic on clinical presentation, treatments, and outcomes of new breast cancer patients: A retrospective multicenter cohort study.

BACKGROUND: The SARS CoV-2 pandemic disrupted healthcare systems. We compared the cancer stage for new breast cancers (BCs) before and during the pandemic. METHODS: We performed a retrospective multicenter cohort study on the data warehouse of Greater Paris University Hospitals (AP-HP). We identified all female patients newly referred with a BC in 2019 and 2020. We assessed the timeline of their care trajectories, initial tumor stage, and treatment received: BC resection, exclusive systemic therapy, exclusive radiation therapy, or exclusive best supportive care (BSC). We calculated patients' 1-year overall survival (OS) and compared indicators in 2019 and 2020. RESULTS: In 2019 and 2020, 2055 and 1988, new BC patients underwent cancer treatment, and during the two lockdowns, the BC diagnoses varied by -18% and by +23% compared to 2019. De novo metastatic tumors (15% and 15%, p = 0.95), pTNM and ypTNM distributions of 1332 cases with upfront resection and of 296 cases with neoadjuvant therapy did not differ (p = 0.37, p = 0.3). The median times from first multidisciplinary meeting and from diagnosis to treatment of 19 days (interquartile 11-39 days) and 35 days (interquartile 22-65 days) did not differ. Access to plastic surgery (15% and 17%, p = 0.08) and to treatment categories did not vary: tumor resection (73% and 72%), exclusive systemic therapy (13% and 14%), exclusive radiation therapy (9% and 9%), exclusive BSC (5% and 5%) (p = 0.8). Among resected patients, the neoadjuvant therapy rate was lower in 2019 (16%) versus 2020 (20%) (p = 0.02). One-year OS rates were 99.3% versus 98.9% (HR = 0.96; 95% CI, 0.77-1.2), 72.6% versus 76.6% (HR = 1.28; 95% CI, 0.95-1.72), 96.6% versus 97.8% (HR = 1.09; 95% CI, 0.61-1.94), and 15.5% versus 15.1% (HR = 0.99; 95% CI, 0.72-1.37), in the treatment groups. CONCLUSIONS: Despite a decrease in the number of new BCs, there was no tumor stage shift, and OS did not vary.

Inventories of Human Lateral Preference: A Systematic Review.

There are a variety of inventories available to evaluate human lateral preference, but no previous review has systematically analyzed and compared them. We conducted a systematic literature review to identify these inventories and describe their characteristics (e.g., dimensions, scales, tasks, psychometric properties). We included 26 articles, each presenting a different inventory to assess lateral preference, published between 1900 and 2022, selected from the following databases: PubMed, SportDiscus, APA PsycNET, and Web of Science. These inventories analyzed tasks performed in everyday life (domestic, work-related, sports, and leisure/recreation activities), covering hand, foot, hearing, visual and other non-usual lateral preference dimensions, such as trunk and head. Most inventories classified individuals based on the direction (left, indifferent or right preference) and degree (consistent or moderate) of laterality. However, many of the reviewed inventories lack established psychometric verification in their original publication, such as validity, reliability, responsiveness, and practical applicability. Inventories also presented tasks that may be specific to a given cultural setting, limiting their application across different countries. Based on these findings, we provide a comprehensive guide for researchers to select a lateral preference assessment tool, but also advocate for a new inventory with a broader approach, containing more than one dimension of lateral preference (i.e., not only handedness) and tasks that are common to different cultures to enhance practical applicability worldwide.

"A vaccine that nonetheless remains apart": Papillomavirus and vaccination in France / « Un vaccin qui reste quand même à part ¼ : Papillomavirus et vaccination en France

Introduction: Vaccination against the human papillomavirus (HPV) is currently not widespread in France, where the vaccination rate is one of the lowest in Europe. However, this virus is encountered by 80% of the population and causes 3000 new cases of cancer per year. This vaccination constitutes a real lever for action. Purpose of research: Using a qualitative approach (semi-directive interviews), we documented the perceptions, reluctance, and obstacles of sixteen general practitioners in Ile de France. The objective was to understand the low vaccination rate and to propose sustainable solutions to increase adherence to this vaccine. Results: The HPV vaccine is different from other vaccines, which makes it more difficult for the public to understand. Firstly, because it affects the privacy of patients from a very young age. Secondly, because it has long been dedicated to a female public and the opening of vaccination to boys of the same age leads to a change in discourse and a break with its gendered image. Finally, this vaccination is taking place in a context where there is a marked reluctance to vaccinate in France, with a rapid circulation of more or less reliable information that often places the medical profession in difficulty. Conclusions: Health professionals play a key role in convincing and encouraging patients to adhere to the vaccine, and a majority of doctors are still in favor of vaccination. Relying on a wider group of health professionals could help to increase adherence to the vaccine in France.

Introduction: La vaccination contre le papillomavirus humain (HPV) est aujourd'hui peu répandue en France où le taux vaccinal est l'un des plus faibles d'Europe. Pourtant, ce virus est rencontré par 80 % de la population et entraine 3 000 nouveaux cas de cancers du col de l'utérus par an. Cette vaccination constitue un réel levier d'action, notamment par le biais des médecins généralistes. But de l'étude: L'objectif était de comprendre le faible taux vaccinal en France et de proposer des solutions durables pour augmenter l'adhésion à ce vaccin. Avec une approche qualitative, nous avons documenté les perceptions, réticences et obstacles de seize médecins généralistes en Île de France. Résultats: Le vaccin anti-HPV présente des particularités qui rendent son abord plus délicat auprès de la population. D'abord, parce qu'il touche à l'intimité des patients et ce, dès un très jeune âge. Ensuite, parce qu'il a longtemps été dédié à un public féminin ; l'ouverture de la vaccination aux garçons du même âge entraine donc une modification des discours et une rupture avec son image genrée. Enfin, cette vaccination s'inscrit dans un contexte où l'hésitation vaccinale est marquée en France, avec une circulation rapide d'informations plus ou moins fiables venant souvent mettre en difficulté le corps médical. Conclusions: Les professionnels de santé détiennent un rôle clé pour convaincre et entrainer l'adhésion des patients, et une majorité des médecins reste favorable à cette vaccination. S'appuyer sur un ensemble de professionnels de santé plus large pourrait permettre d'augmenter l'adhésion vaccinale en France.

Low-Load x High-Load Resistance Exercise: Greater Cell Swelling After a Training Session.

Cell swelling caused by resistance training is proposed to provide an anabolic stimulus for muscle growth and it is believed that these effects are heightened with the use of low loads. The purpose of this study was to compare the acute effects of two volume-equated resistance training (RT) protocols, low-load (LL) versus high-load (HL), on elbow flexor muscles thickness, arm circumference, and blood lactate concentration in well-trained individuals. Eight resistance-trained males performed the following two RT protocols involving unilateral elbow flexion of the dominant arm: i) LL, four sets with 50% 1 repetition-maximum [1 RM] and ii) HL, ten sets with 85% 1 RM until failure, and equated volume. Pre- and post-session measurements included muscle thickness of the elbow flexors (biceps brachii and brachialis), upper arm circumference, and blood lactate concentration. Significant pre- to post-session increases were found in both protocols for muscle thickness (F (1, 28) = 11.74, p = 0.0019), and blood lactate (F (1, 28) = 35.55, p < 0.0001); no statistically significant differences were observed between conditions, however, the magnitude of increases favored LL. Significant between-condition differences favoring LL were observed for total repetitions (p = 0.007), time under tension (p = 0.007), and training density (p = 0.007). These results suggest that LL training promotes superior post-session increases in muscle thickness, indicating that RT protocols with longer times under tension and densities are beneficial when the goal is to promote acute cell swelling.

Prediction of ball direction in soccer penalty through kinematic analysis of the kicker.

The penalty kick is a crucial opportunity to score and determine the outcome of a soccer match or championship. Anticipating the direction of the ball is key for goalkeepers to enhance their defensive capabilities, considering the ball's swift travel time. However, it remains unclear which kinematic cues from the kicker can predict the ball's direction. This study aimed to identify the variables that predict the ball's direction during a soccer penalty kick. Twenty U19 soccer players executed penalty kicks towards four targets positioned in the goal, while kinematic analysis was conducted using a 3D motion analysis system. Logistic regression analysis revealed that trunk rotation in the transverse plane (towards the goal - left; or slightly to the right - right) served as the primary predictor of the ball's horizontal direction at 250 and 150 ms before the kicking foot made contact. Additionally, the height of the kicking foot in the sagittal plane solely predicted the vertical direction at the moment of contact. This information, encompassing trunk rotation and kicking foot height, can be employed in perceptual training to enhance decision-making and the implementation of feints during penalty kicks.

[Diagnosis and management of interstitial lung disease induced by antibody-drug conjugates in breast cancer: A French expert opinion paper]. / Diagnostic et prise en charge de la pneumopathie interstitielle diffuse induite par les anticorps conjugués dans le cancer du sein : avis d'expert.

Interstitial lung disease (ILD) has been reported with many cancer drugs including some recent antibody-drug conjugates (ADCs). The mechanisms of ILD induced by many chemotherapy drugs, other drug classes and ADCs used in cancer, including breast cancer, are not clearly elucidated. In the absence of specific clinical or radiological signs, the diagnosis of drug-induced ILD is often a diagnosis of exclusion. When present, the most frequent symptoms are respiratory signs (cough, dyspnea, chest pain) and general signs (fatigue, fever). Any suspicion of ILD should be evaluated by imaging and, if in doubt, the CT scan should be evaluated by a pulmonologist and a radiologist. A network of multidisciplinary experts for proactive early management of ILD is important, including oncologist, radiologist, pulmonologist, infectious disease specialist and nurses. Patient education is essential to report new or exacerbated lung symptoms and prevent high-grade ILD. Study drug is discontinued temporarily or permanently according to ILD severity and type of ADC. For asymptomatic cases (Grade 1), the efficacy of corticosteroids is not clearly established; for higher grades, the benefit/risk balance of long-term corticosteroid therapy should be considered for the dose and treatment duration. Hospitalization and oxygen supplementation are required for severe cases (Grades 3-4). For patient follow-up, the expertise of a pulmonologist is necessary with repeated chest scans, spirometry and DLCO. Preventing ADC-induced ILDs and evolution to high grade rests on a network of multidisciplinary experts for assessment of individual risk factors, early management, close follow-up and patient education.

Perturbation-based balance training leads to improved reactive postural responses in individuals with Parkinson's disease and freezing of gait.

Perturbation-based balance training (PBT) exposes individuals to a series of sudden upright balance perturbations to improve their reactive postural responses. In this study, we aimed to evaluate the effect of a short PBT program on body balance recovery following a perturbation in individuals with freezing of gait due to Parkinson's disease. Volunteers (mean age = 64 years, SD = 10.6) were pseudorandomly assigned either to a PBT (n = 9) or to a resistance training (RT, n = 10) group. PBT was implemented through balance perturbations varying in the kind, direction, side and magnitude of support base displacements. Both groups exercised with progressive difficulty/load activities twice a week for 4 weeks. Specific gains and generalization to dual-tasking and faster-than-trained support base displacements were evaluated 24 h after the end of the training, and retention was evaluated after 30 days of no training. Results showed that, compared with RT, PBT led to more stable postural responses in the 30-day retention evaluation, as indicated by decreased CoP displacement, velocity and time to direction reversal and reduced numbers of near-falls. We found no transfer either to a dual task or to a higher perturbation velocity. In conclusion, a training program based on diverse unpredictable balance perturbations improved the stability of reactive postural responses to those perturbations suffered during the training, without generalization to more challenging tasks.

Backseat Inclination Affects the Myoelectric Activation During the Inclined Leg Press Exercise in Recreationally Trained Men.

ABSTRACT: Marchetti, PH, Gomes, WA, Da Silva, JJ, Magalhaes, RA, Teixeira, LFM, and Whiting, WC. Backseat inclination affects the myoelectric activation during the inclined leg press exercise in recreationally trained men. J Strength Cond Res 37(10): e541-e545, 2023-Changes in the angle between the seat and backrest during the inclined leg press (ILP) exercise may influence myoelectric activity. The purpose of this study was to evaluate the myoelectric activity between 2 different angles between the seat and backrest (90° and 125°) during the ILP exercise in recreationally trained men. Fifteen young, resistance-trained men (age: 26.8 ± 5.3 years, height: 173.8 ± 6.6 cm, total body mass: 81.6 ± 7.6 kg) performed 1 set of 10 repetitions at 70% of their body mass during the ILP exercise using 2 different angles between the seat and backrest (ILP90° and ILP125°). Surface electromyography (peak RMS 90 and iEMG) was used to measure the myoelectric activity of the vastus lateralis (VL), biceps femoris (BF), and gluteus maximus (GM). A paired t test was used to measure differences in knee and hip joint displacement, peak RMS 90 , and iEMG between ILP90 and ILP125. The hip angle presented a greater displacement during the ILP125 when compared with ILP90 ( p < 0.001), considering a similar knee joint displacement. For the VL, there was observed greater myoelectric activation (peak RMS 90 and iEMG) during ILP125 when compared with ILP90 ( p < 0.05). For the BF, there was observed greater myoelectric activation (peak RMS 90 and iEMG) during ILP90 when compared with ILP125 ( p < 0.05). However, GM did not present differences between ILP90 and ILP125. In conclusion, the angle between the seat and backrest (ILP90 or ILP125) altered the myoelectric activation of the VL and BF with no difference for the GM.

Control of interjoint coordination in the performance of manual circular movements can explain lateral specialization.

Between-arm performance asymmetry can be seen in different arm movements requiring specific interjoint coordination to generate the desired hand trajectory. In the current investigation, we assessed between-arm asymmetry of shoulder-elbow coordination and its stability in the performance of circular movements. Participants were 16 healthy right-handed university students. The task consisted of performing cyclic circular movements with either the dominant right arm or the nondominant left arm at movement frequencies ranging from 40% of maximum to maximum frequency in steps of 15%. Kinematic analysis of shoulder and elbow motions was performed through an optoelectronic system in the three-dimensional space. Results showed that as movement frequency increased circularity of left arm movements diminished, taking an elliptical shape, becoming significantly different from the right arm at higher movement frequencies. Shoulder-elbow coordination was found to be asymmetric between the two arms across movement frequencies, with lower shoulder-elbow angle coefficients and higher relative phase for the left compared to the right arm. Results also revealed greater variability of left arm movements in all variables assessed, an outcome observed from low to high movement frequencies. From these findings, we propose that specialization of the left cerebral hemisphere for motor control resides in its higher capacity to generate appropriate and stable interjoint coordination leading to the planned hand trajectory.