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Background: An increased number of breast cancer patients are challenged by acute and persistent treatment side effects. Oncology guidelines have been establishing physical exercise to counteract several treatment-related toxicities throughout cancer care. However, evidence regarding the optimal dose-response, feasibility, and the minimal resistance exercise volume and/or intensity remains unclear. The ABRACE Study will assess the impact of different resistance training volumes (i.e., single or multiple sets) combined with aerobic exercise on physical and psychological outcomes of breast cancer patients undergoing primary treatment. Methods: This study is a randomized, controlled, three-armed parallel trial. A total of 84 participants, aged ≥18 years, with breast cancer stages I-III, initiating adjuvant or neoadjuvant chemotherapy (≤50% of sessions completed) will be randomized to multiple sets resistance training plus aerobic training group, single set resistance training plus aerobic training group or control group. Neuromuscular and cancer-related fatigue (primary outcomes), muscle strength, muscle thickness, muscle quality by echo intensity, body composition, cardiorespiratory capacity, functional performance, upper-body endurance and quality of life will be measured before and after the 12-week intervention. Our analysis will follow the intention-to-treat approach and per-protocol criteria, with additional sub-group analysis. Discussion: Findings support prescribing exercise during chemotherapy for breast cancer and elucidate the potential role of different resistance training volumes as a management strategy for physical and psychological impairments in women with early-stage breast cancer. Our main hypothesis is for superiority in physical and psychological outcomes for both training groups compared to the control group, with no difference between single or multiple sets groups. Trial registration: Clinical trials NCT03314168.

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SUMMARY: Anatomical studies describe the vastus medialis (VM) as being subdivided into two morphologically distinct components, the vastus medialis obliquus (VMO) and the vastus medialis longus (VML). However, there are discrepancies regarding the functional differentiation of these components. The aim of this study was to compare the levels of activation of the VMO and the VML by high density surface electromyography. Twelve healthy young women (age: 21.4 ± 2.0 years; weight: 58.1 ± 7.5 kg; height: 1.6 ± 0.1 m), performed an open kinetic chain knee exercise during which the EMG activity of the VMO and the VML was recorded with two- dimensional matrices of 32 surface electrodes. The exercises were performed with three levels of resistance (5, 10 and 15 % of the body weight (BW)), considering three phases: concentric, isometric and excentric. In the isometric phase the VMO had greater activation than the VML with the three levels of resistance (p<0.05). In the excentric phase, the VMO also showed greater activation than the VML with the 10 and 15 % BW resistance levels, while in the concentric phase, the VMO showed greater activity than the VML with only the 15 % BW resistance. The results indicated significant differences in the activation level of the two components of the VM. This bears importance in the development of exercises intended to achieve a greater or more selective activation of the VMO. In the sample subjected to evaluation, the EMG recordings describe a greater activation of the VMO in comparison to the VML, which is more important in the isometric and excentric phases of the flexion/extension of the knee in an open kinetic chain. These findings suggest a functional compartmentalization of the VM.

RESUMEN: Los estudios anatómicos describen que el músculo vasto medial (VM) se subdivide en dos componentes morfológicamente distintos, el vasto medial obliquus (VMO) y el vasto medial largo (VML). Sin embargo, existen discrepancias con respecto a la diferenciación funcional de estos componentes. El objetivo de este estudio fue comparar los niveles de activación del VMO y el VML mediante electromiografía de superficie de alta densidad. Doce mujeres jóvenes sanas (edad: 21,4 ± 2,0 años; peso: 58,1 ± 7,5 kg; altura: 1,6 ± 0,1 m), realizaron un ejercicio de rodilla de cadena cinética abierta durante el cual se registró la actividad EMG de la VMO y la VML con dos matrices dimensionales de 32 electrodos de superficie. Los ejercicios se realizaron con tres niveles de resistencia (5, 10 y 15% del peso corporal (PC)), considerando tres fases: concéntrica, isométrica y excéntrica. En la fase isométrica el VMO tuvo mayor activación que el VML con los tres niveles de resistencia (p <0,05). En la fase excéntrica, el VMO también mostró mayor activación que el VML con los niveles de resistencia de 10 y 15% BW, mientras que en la fase concéntrica, el VMO mostró mayor actividad que el VML con solo el 15 % de resistencia al BW. Los resultados indicaron diferencias significativas en el nivel de activación de los dos componentes de la VM. Esto tiene importancia en el desarrollo de ejercicios destinados a lograr una activación mayor o más selectiva del VMO. En la muestra sometida a evaluación, los registros EMG describen una mayor activación del VMO en comparación con el VML, que es más importante en las fases isométrica y excéntrica de la flexión / extensión de la rodilla en cadena cinética abierta. Estos hallazgos sugieren una compartimentación funcional de la VM.

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ABSTRACT Introduction: Muscle activity in the pedal stroke movement on a cycle ergometer can be measured by surface electromyography, as an effective and improved method for studying muscle action and objectively determining the different action potentials of the muscles involved in specific movements. Heart rate behavior is an important factor during exercise with load. Objective: To identify heart rate behavior and pattern of muscle activity of the rectus femoris and vastus medialis in healthy subjects in the pedaling dynamic at different loads, submaximal test, on an instrumented cycle ergometer. Methods: 20 healthy adults were evaluated. Heart rate measurement was performed, together with electromyographic analysis, in the time domain, of the rectus femoris and vastus medialis muscles during incremental exercise of the lower limbs on the cycle ergometer. Results: Heart rate behavior presented significant difference for p≥0.05 in relation to increased loads. The EMG signal intensity from the vastus medialis muscle (normalized RMS value) in each quadrant of the pedaling cycle showed significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants III and IV. In the rectus femoris (RF) muscle, there was significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants I, II and III. Conclusion: An increase in heart rate proportional to the increase in load was observed, as well as an increase in the amplitude of the electromyographic signal proportional to the increase in load. It was possible to identify the pattern of muscle activation in the studied quadrants during pedal stroke movements, independent of load. Level of evidence III; Study of non-consecutive patients; without uniform application of the "gold" standard reference.

RESUMO Introdução: A atividade muscular no gesto motor da pedalada no cicloergômetro pode ser mensurada por meio da eletromiografia de superfície. A eletromiografia de superfície tem sido um método efetivo e aprimorado para estudar a ação muscular, determinando com objetividade os diferentes potenciais de ação dos músculos empenhados em movimentos específicos. O comportamento da frequência cardíaca tem relação importante durante o exercício com carga. Objetivo: Identificar o comportamento da frequência cardíaca e o padrão da atividade muscular do reto femoral e vasto medial em indivíduos saudáveis na dinâmica da pedalada em diferentes cargas, teste submáximo, no cicloergômetro instrumentado. Métodos: Foram avaliados 20 adultos saudáveis, realizando-se a mensuração da frequência cardíaca e a análise eletromiográfica no domínio do tempo dos músculos reto femoral e vasto medial durante o exercício incremental dos membros inferiores em cicloergômetro. Resultados: O comportamento da frequência cardíaca apresentou diferença significante para p ≥ 0,05 com relação ao incremento das cargas. A intensidade do sinal EMG do músculo vasto medial (valor RMS normalizado) em cada quadrante do ciclo da pedalada mostrou diferença significativa para p ≥ 0,05 com relação aos quadrantes I, II e IV e diferença significativa para p ≥ 0,05 com relação aos quadrantes III e IV. No músculo reto femoral (RF) verificou-se diferença significativa para p ≥ 0,05 com relação aos quadrantes I, II e IV e diferença significativa para p ≥ 0,05 com relação aos quadrantes I, II e III. Conclusão: Constatou-se aumento da frequência cardíaca proporcional ao incremento das diferentes cargas e também se evidenciou um aumento na amplitude do sinal eletromiográfico proporcional ao incremento da carga. Foi possível identificar o padrão da ativação dos músculos com relação ao ciclo da pedalada nos quadrantes estudados, independentemente do nível da carga. Nível de evidência III; Estudo de pacientes não consecutivos; sem padrão de referência "ouro" aplicado uniformemente.

RESUMEN Introducción: La actividad muscular en el gesto motor de la pedaleada en el cicloergómetro se puede medir por medio de la electromiografía de superficie. La electromiografía de superficie ha sido un método efectivo y mejorado para estudiar la acción muscular, determinando con objetividad los diferentes potenciales de acción de los músculos empeñados en movimientos específicos. El comportamiento de la frecuencia cardíaca tiene relación importante durante el ejercicio con carga. Objetivo: Identificar el comportamiento de la frecuencia cardíaca y el patrón de la actividad muscular del recto femoral y vasto medial en individuos en la dinámica de la pedaleada en el cicloergómetro instrumentado. Métodos: Se evaluaron 20 adultos saludables, realizándose la medición de la frecuencia cardíaca y el análisis electromiográfico en el dominio del tiempo de los músculos recto femoral y vasto medial durante el ejercicio incremental de los miembros inferiores en cicloergómetro. Resultados: El comportamiento de la frecuencia cardíaca presentó una diferencia significativa para p ≥ 0,05 con relación al incremento de las cargas. La intensidad de la señal EMG del músculo vasto medial (valor RMS normalizado) en cada cuadrante del ciclo de la pedaleada mostró diferencia significativa para p ≥ 0,05 con relación a los cuadrantes I, II y IV y diferencia significativa para p ≥ 0,05 con relación a los cuadrantes III y IV. En el músculo recto femoral (RF) se verificó diferencia significativa para p ≥ 0,05 con relación a los cuadrantes I, II y IV, y diferencia significativa para p ≥ 0,05 con relación a los cuadrantes I, II y III. Conclusión: Se constató aumento de la frecuencia cardíaca proporcional al incremento de las diferentes cargas y también se evidenció un aumento en la amplitud de la señal electromiográfica proporcional al incremento de la carga. Fue posible identificar el patrón de la activación de los músculos con relación al ciclo de la pedaleada en los cuadrantes estudiados, independientemente del nivel de la carga. Nivel de evidencia III; Estudio de pacientes no consecutivos; sin patrón de referencia "oro" aplicado uniformemente.

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BACKGROUND: The anatomy and function of the quadriceps muscle play a role in patellofemoral stability. Few studies have evaluated anatomic differences in the vastus medialis between patients with and without patellar instability. PURPOSE: To compare the anatomy of the vastus medialis using magnetic resonance imaging in patients with patellar instability to a control group. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A group of patients with patellar instability were sex-matched with a control group with anterior cruciate ligament tears, meniscal injuries, or sprains; patients younger than 15 years were excluded. The anatomy of the vastus medialis was examined by the distance between the distal origin of the vastus medialis in the femur and the medial femoral condyle, the distance from the proximal pole of the patella to the most distal insertion of the muscle and its ratio to the length of the articular surface of the patella, and a qualitative description of the insertion position of the muscle fibers (directly in the patella or the medial retinaculum). RESULTS: Both groups comprised 78 knees (48 female; 61.5%). The mean age in the control and patellar instability groups was 30.2 ± 7.8 years and 25.6 ± 7.5 years, respectively (P = .001). The distance from the vastus origin to the condyle was 27.52 ± 3.49 mm and 26.59 ± 3.43 mm, respectively (P = .041); the distance from the proximal pole of the patella to the most distal muscle insertion was 17.59 ± 5.54 mm and 15.02 ± 4.18 mm, respectively (P < .001); and the ratio of this distance to the joint surface was 0.586 ± 0.180 and 0.481 ± 0.130, respectively (P < .001). In 75.6% of knees in the patellar instability group, the insertion of the vastus was into the medial retinaculum and not into the patella compared with 52.6% in the control group (P = .003; odds ratio, 2.8). CONCLUSION: The distal insertion of the vastus medialis differed in knees with patellar instability, with a more proximal insertion and less patellar coverage relative to controls, and was more frequently found in the retinaculum instead of directly in the patella.

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INTRODUCTION: Previous evidence suggests the fibers of different motor units reside within distinct vastus medialis (VM) regions. It remains unknown whether the activity of these motor units may be modulated differently. Herein we assess the discharge rate of motor units detected proximodistally from the VM to address this issue. METHODS: Surface electromyograms (EMGs) were recorded proximally and distally from the VM while 10 healthy subjects performed isometric contractions. Single motor units were decomposed from surface EMGs. The smoothed discharge rates of motor units identified from the same and from different VM regions were then cross-correlated. RESULTS: During low-level contractions, the discharge rate varied more similarly for distal (cross-correlation peak; interquartile interval: 0.27-0.40) and proximal (0.28-0.52) than for proximodistal pairs of VM motor units (0.20-0.33; P = 0.006). DISCUSSION: The discharge rates of motor units from different proximodistal VM regions show less similarity in their variations than those of pairs of units either distally or proximally. Muscle Nerve 57: 279-286, 2018.

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Introducción La inestabilidad lateral femororrotuliana es una patología de etiología multifactorial aunque existen múltiples opciones para su tratamiento. El adelantamiento del vasto medial con liberación retinacular lateral asistida por artroscopia (AVMLRAA) se realiza cuando no hay alteraciones de alineación ni de la estructura ósea. El objetivo del estudio es evaluar los resultados clínicos y funcionales de pacientes con inestabilidad lateral femororrotuliana (ILFR) tratados con AVMLRAA. Material y métodos Estudio descriptivo y transversal realizado entre septiembre de 2014 y enero de 2016. Se incluyó a pacientes con ILFR tratados con AVMLRAA. Se presentan los resultados evaluados por las escalas de Tegner-Lysholm y Kujala antes de la cirugía y 12meses después de operados. Resultados Seis pacientes, 5 mujeres (83,3%) y 1 hombre (16,7%); media de edad al presentar la primera luxación: 15,83 (7-30) ±8,47 años; rodilla afectada: 4 derechas (66,7%) y 2 izquierdas (33,3%); tiempo promedio desde la primera luxación hasta la cirugía: 10,08 (0,5-17) ±5,16 años; las evaluaciones prequirúrgicas y posquirúrgicas de las escalas Tegner-Lyshom y Kujala para el género y lado afectado no mostraron diferencias estadísticamente significativas (p>0,05). La mediana prequirúrgica de la escala Tegner-Lysholm fue 37,50 (6-78) ±26,66; posquirúrgica: 88,17 (77-99) ±7,73 (p = 0,028); mediana de la escala Kujala prequirúrgica: 36,67 (2-77) ±29,703; posquirúrgica: 84,83 (75-100) ±9,368 (p = 0,027). El seguimiento promedio fue 14,0 (12-18) ±2,44 meses; la aprensión posquirúrgica fue 100% negativa. El 100% respondió que se volverían a operar en caso de presentar nuevamente los síntomas. Discusión El AVMLR para el manejo de la ILFR en pacientes sin malformaciones óseas ni mala alineación ofrece buenos resultados clínicos. Nivel de evidencia clínica Nivel IV.

Background Patellofemoral lateral instability is a condition of multifactorial origin, and has multiple options for its treatment. Vastus medialis advancement with arthroscopic assisted lateral retinacle replication (AALRR) is performed when there is no alteration of alignment or bone structure. The purpose of this study is to evaluate the clinical and functional results of patients with patellofemoral lateral instability (PFLI) treated with AALRR. Material and methods A descriptive, cross-sectional study was conducted from September 2014 to January 2016 on patients with PFLI treated with AALRR. The results before surgery and 12months after surgery, were evaluated using the Tegner-Lysholm and Kujala scales. Results The study included 6 patients, 5women (83.3%), and 1man (16.7%). The median age at first dislocation was 15.83 (7-30) ±8.47years. The affected knees were 4right (66.7%) and 2left (33.3%). The mean time from first dislocation to surgery was 10.08 (0.5-17) ±5.16years. The pre- and post-surgical evaluations using the Tegner-Lysholm and Kujala scales for the affected gender and side showed no statistically significant differences (P>.05). The pre-surgical median of the Tegner-Lysholm scale was 37.50 (6-78) ±26.66, and post-surgical, 88.17 (77-99) ±7.73 (P=.028). The pre-surgical and post-surgical median of the Kujala scale was 36.67 (2-77) ±29.703, and 84.83 (75-100) ±9.368, respectively (P=.027). The mean follow-up was 14.0 (12-18) ±2.44months.; Post-surgical apprehension was 100% negative. All patients responded that they would have a further operation in case of presenting with the symptoms again. Discussion The AALRR for the management of PFLI in patients without bone malformations or misalignment offers good clinical results. Evidence level IV.

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Although not mentioned directly in the classical anatomical literature, the vastus lateralis and vastus medialis, which make up the quadriceps femoris muscle, show variations in their anatomical structures due to the presence of long and oblique portions receiving the designation of vastus lateralis longus, vastus lateralis obliques to the vastus lateralis and vastus medialis oblique and vastus long, for the vastus medialis. The aim of this paper is to review the scientific literature regarding the presence of long and oblique portions of the broad medial and lateral portions recognize these as integral parts, anatomically, the quadriceps femoris. To this end, we used published articles in magazines and journals, located through Medline, and Lilacs Excerpa Medica, and the Portal Capes, with the key words: quadriceps, vastus medialis, vastus lateralis, vastus medialis longus, vastus medialis oblique , vastus lateralis longus and vastus lateralis oblique. Used to, still, a master’s thesis, located at Portal Capes, plus textbooks and atlases of anatomy. Among the 27 surveyed, only two do not recognize these portions as independent structures, considering the differences in fiber orientation. Of the 18 studied anatomy books, no mention such parts. However, eight anatomy books describe differences in trajectory of fiber insertions of the vastus lateralis and vastus medialis. Before this study it was concluded that these portions have not only morphological differences but also in other respects proved through scientific studies being published in some of them considered independent muscle suggesting inclusion of muscles in Anatomical Nomina.

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Trends in variation of physical, chemical and sensory traits due to country of origin (COO) were evaluated for samples from United States of America (U.S.A.) and Mexico of three pork muscles, Rectus femoris (RF, n = 20 from each COO), Vastus medialis (VM, n = 20 from each COO), and Longissimus dorsi (LD, n = 10 from each COO) in two separate, small-scale, exploratory surveys conducted at Mexico City. Compositional, physical and chemical properties and consumer acceptability traits of these Mexican and U.S.A. pork samples were quite similar, though Mexican pork samples generally were more variable. LD samples from U.S.A. had greater (P<0.05) water-holding and emulsifying capacities whereas both RF and LD from U.S.A. required lower shear force (P<0.05) compared to Mexican counterparts. Ratings from consumers did not indicate preference for pork from any of the countries. Because of the limited number of observations for the samples surveyed these results are preliminary and may not adequately characterize the populations of each country, but they did reveal important trends for selected traits of Mexican and U.S.A. pork currently available at the local market.

Se evaluaron tendencias en la variación de características físico-químicas y sensoriales debidas al país de origen (PDO), de muestras mexicanas y estadounidenses (EUA) de tres músculos del cerdo: Rectus femoris (RF, n = 20 por PDO), Vastus medialis (VM, n = 20 por PDO), and Longissimus dorsi (LD, n = 10 por PDO) mediante dos encuestas exploratorias separadas, a baja escala, conducidas en la Ciudad de México. Los resultados mostraron que músculos porcinos de los dos orígenes tienen propiedades físicas, químicas y sensoriales muy similares, aunque las muestras mexicanas mostraron mayor variabilidad. Las muestras de LD de EUA tuvieron mayor (P<0,05) capacidad de retención de agua y emulsificación, y al igual que las de RF, requirieron menos fuerza de corte que las mexicanas (P<0,05). Los consumidores no pudieron detectar diferencias entre muestras de diferente origen. Debido al limitado número de observaciones en las muestras encuestadas, los resultados deben considerarse preliminares y si bien no permiten caracterizar adecuadamente las poblaciones de cada país, las mismas revelan tendencias importantes para los rasgos seleccionados de la carne de cerdo procedente de México y EUA disponibles actualmente en el mercado local.

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A Síndrome da dor patelofemoral (SDPF) é descrita como dor anterior ou retro-patelar do joelho na ausência de outras patologias associadas, sendo freqüentemente associada à disfunção do Vasto Medial Oblíquo (VMO). Entretanto, diversos estudos têm demonstrado a impossibilidade de ativar seletivamente este músculo através de exercícios. O objetivo do presente estudo foi analisar o efeito imediato da estimulação elétrica neuromuscular (EENM) seletiva no músculo VMO por meio do comportamento eletromiográfico dos músculos VMO e vasto lateral (VL). Foram avaliadas 18 mulheres saudáveis, com idade média de 23,2 anos e IMC médio de 20 Kg/m2. Os procedimentos do estudo incluíram uma análise eletromiográfica dos músculos VMO e VL, antes e imediatamente após a EENM do músculo VMO. Durante a análise eletromiográfica, as voluntárias realizaram uma contração isométrica voluntária máxima durante a extensão do joelho a 60° em um dinamômetro isocinético. A estimulação elétrica foi realizada através da corrente Russa. A análise dos dados mostrou um aumento significativo na intensidade de ativação do músculo VMO imediatamente após a estimulação do mesmo (p=0,0125), enquanto que a intensidade de ativação do músculo VL, não mostrou aumento significativo (p=0,924). Além disso, verificou-se também um aumento significativo na relação VMO/VL (p=0,048). No presente estudo, observou-se uma modificação na relação VMO/VL após a EENM, sugerindo que a mesma tem um efeito favorável no fortalecimento seletivo do VMO...

The Patellofemoral pain syndrome (PFPS) is described as an anterior or retropatellar knee pain in the absence of other associated diseases, and has often been associated with dysfunction of the vastus medialis oblique muscle (VMO). However, several studies have demonstrated the impossibility of selectively activating this muscle with exercises. The aim of the present study was to analyze the immediate effect of neuromuscular electrical stimulation of VMO muscle by means of monitoring the electromyographic activity of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles. Eighteen healthy women with a mean age of 23.2 years and mean BMI of 20 Kg/m2 were evaluated. The study protocol included electromyographic analysis of VMO and VL muscles, before and immediately after neuromuscular electrical stimulation of the VMO muscle. During the electromyographic analysis, the volunteers performed maximal voluntary isometric contraction in a 60° knee extension on an isokinetic dynamometer. ôRussian currentõ apparatus was used for electrical stimulation. Results: The data analysis demonstrated a signifi cant increase in VMO activation intensity immediately after it had been electrically stimulated (p=0.0125), whereas VL activation intensity exhibited no signifi cant increase (p=0.924). Moreover, a signifi cant increase in the VMO/VL ratio was also detected (p=0.048). In this study it was observed that electrical stimulation modifi ed the VMO/VL ratio, which suggests electrical stimulation has a benefi cial effect on VMO muscle strength...

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