Frequency and characterization of the accessory heads of the biceps brachii: A multicentric cadaveric study.

PURPOSE: The biceps brachii muscle (BBM) is a large and thick muscle on the ventral portion of the upper arm. The scientific literature reports the existence of extra heads. OBJECTIVE: The present work investigated the frequency of occurrence of BBM accessory head(s) in four different Anatomy Laboratories at universities in Northeast Brazil. MATERIAL AND METHODS: Once the upper limbs with an anatomical variation of the BBM heads were identified, the accessory head was evaluated for morphometric characterization (the length, width, and thickness). RESULTS: The sample consisted of 249 upper limbs and the outcomes were 26 members with BBM accessory heads (10.44% of the total sample). Among the 26 members studied was found a single accessory head in 22 (84.62%), two accessory heads in 3 (11.54%), and three accessory heads in 1 (3.85%). BBMs with one, two, and three accessory heads were found, with different origins. The average length, width, and thickness of these accessory heads were 169.39mm, 10.25mm, and 3.39mm, respectively. CONCLUSION: The frequency of BBM accessory heads in a population of northeastern Brazil in this cadaveric study was 10.44%.

Six asymmetric bilateral additional heads of biceps brachii muscle observed in a cadaver / Seis cabezas adicionales bilaterales asimétricas del músculo bíceps braquial observadas en un cadáver

SUMMARY: Anatomic variation of the biceps brachii muscle (BBM) is frequently observed; its pattern is diverse and clinically important. During the educational dissection of a 78-year-old Korean male cadaver, six additional asymmetrical heads of the biceps brachii muscle (BBM) were found on both sides. On the right side, two additional heads originated from the humerus; the musculocutaneous nerve passed between these heads and the short head of the BBM. Four additional heads were found on the left side, anterior to the BBM, one of which originated from the pectoralis major muscle. Posterior to the BBM, two heads of tendons originated from the coracobrachialis muscle and one head of the muscle belly originated from the humerus. The left musculocutaneous nerve pierced the coracobrachialis muscle and continued distally passing between the short head of the BBM and the additional heads located posterior to the BBM. It then gave off the variant musculocutaneous nerve to the median nerve. On both sides, the short and long heads of the BBM had normal origins, insertions, and courses. This novel variation has various clinical and embryological implications.

RESUMEN: Con frecuencia se observa una variación anatómica del músculo bíceps braquial (MBB); su patrón es diverso y clínicamente importante. Durante la disección de un cadáver masculino coreano de 78 años, se encontraron seis cabezas asimétricas adicionales del músculo bíceps braquial en ambos lados. En el lado derecho, dos cabezas adicionales se originaban en el húmero; el nervio musculocutáneo atravesaba entre estas cabezas y la cabeza corta del MBB. Se encontraron cuatro cabezas adicionales en el lado izquierdo, anterior al MBB, una de las cuales se originaba en el músculo pectoral mayor. Posterior al MBB, dos cabezas tendinosas se originaban en el músculo coracobraquial y una cabeza de vientre muscular se originaba en el húmero. El nervio musculocutáneo izquierdo perforaba el músculo coracobraquial y continuaba distalmente pasando entre la cabeza corta del MBB y las cabezas adicionales ubicadas por detrás del MBB. Luego emitía la variante el nervio musculocutáneo al nervio mediano. En ambos lados, las cabezas corta y larga del MBB tenían orígenes, inserciones y trayectos normales. Esta nueva variación tiene varias implicaciones clínicas y embriológicas.

The innervation of the biceps brachii and brachialis muscles in specimens with a high incidence of an accessory biceps head.

We describe the patterns of motor branches to the elbow flexors in 106 fresh-frozen cadaveric upper extremities from 53 donors of the Latin American mestizo race. We identified a 20% incidence of an accessory biceps head. The innervation patterns to this accessory head were specifically described and added to the Yang classification as Type IV for the biceps and Type III for the brachialis. The patterns arising from the musculocutaneous nerve to the biceps brachii were of Type I in 69%, Type II in 9%, Type III in 7% and Type IV in 11%, and to the brachialis of Type I in 77%, Type II in 11% and Type III in 9%. In 4%, the branches did not originate from the musculocutaneous nerve. We hypothesize that the branch to the accessory biceps head might be considered as a donor for nerve transfer in selected brachial plexus injuries.

Third head of the biceps brachii muscle originated from the greater tubercle connecting long and short heads: a case report / Tercera cabeza del músculo bíceps braquial originada en la tubrosidad mayor del húmero conectando las cabezas larga y corta: informe de un caso

Variation in the biceps brachii muscle is extremely frequent and has a clinical significance. During an educational dissection, third head of the biceps brachii muscle was found on the left side in a Korean cadaver. The short and long heads showed normal morphology and course: however, additional head originated from the greater tubercle connected to long head of biceps brachii muscle and crossed the musculocutaneous nerve perpendicularly. And then, it was inserted into short head of the biceps brachii muscle. The author describes this previously novel case report and discusses the clinical implications of such a variant.

La variación en el músculo bíceps braquial es extremadamente frecuente y tiene un significado clínico. Durante una disección educativa, se encontró la tercera cabeza del músculo bíceps braquial en el lado izquierdo de un cadáver coreano. Las cabezas cortas y largas mostraron una morfología y curso normales: sin embargo, la cabeza adicional se originó de la tuberosidad mayor conectado a la cabeza larga del músculo bíceps braquial y cruzaba el nervio musculocutáneo perpendicularmente, insertándose en la cabeza corta del músculo bíceps braquial. El autor describe este informe de un caso novedoso y discute las implicaciones clínicas de tal variante.

The third head of the biceps brachii muscle perforated by the musculocutaneous nerve / La tercera cabeza del músculo bíceps braquial perforada por el nervio musculocutáneo

During an educational dissection, the third head of the biceps brachii muscle was found on the left side in a 63-yearold female Korean cadaver. The short and long heads showed normal morphology, and their courses were as follows: The third head was originated from the middle level of the humerus under the short head and inserted in the conjoined tendon of the long and short heads of the biceps brachii muscle. The musculocutaneous nerve penetrated the third head of the biceps brachii muscle and became the lateral cutaneous nerve of the forearm. The authors describe this novel case and discuss the clinical implications of such a variation.

Durante una disección educativa, la tercera cabeza del músculo bíceps braquial se encontró en el lado izquierdo en un cadáver coreano de 63 años de edad. La cabeza corta y la cabeza larga mostraron una morfología normal, y se presentaron de la siguiente forma: La tercera cabeza se originó en el nivel medio del húmero, inferior a la cabeza corta, y se insertó en el tendón unido de las cabezas larga y corta del músculo bíceps braquial. El nervio musculocutáneo penetró en la tercera cabeza del músculo bíceps braquial para transformarse en el nervio cutáneo lateral del antebrazo. Los autores describen este nuevo caso y discuten las implicaciones clínicas de esta variación.

Effects of order of resistance training exercises on muscle hypertrophy in young adult men.

The purpose of the present study was to analyze the effects of the order of resistance training (RT) exercises on hypertrophy in young adult men. Thirty-six young adult men (age, 21.9 ± 2.5 years; body mass, 72.6 ± 12.1 kg, height, 176.9 ± 7.4 cm; body mass index, 23.1 ± 3.3 kg/m2) were randomly assigned to 1 of 2 training groups that performed a 6-week RT program in either (i) a traditional approach starting with multi-joint (MJ) exercises followed by single-joint exercises (SJ) (MJ-SJ, n = 19) or (ii) in reverse order (SJ-MJ, n = 17). Muscle thickness of the biceps brachii and mid-thigh were assessed by ultrasound. Lean soft tissue (LST) was assessed by dual-energy X-ray absorptiometry. Both groups similarly increased (P < 0.05) biceps brachii thickness (MJ-SJ = +14.2%, SJ-MJ = +13.8%). Alternatively, only the MJ-SJ group presented an increase in mid-thigh thickness from pre- to post-training (MJ-SJ = +7.2%, SJ-MJ = +3.9%). Upper limb LSTs (MJ-SJ = +5.2%, SJ-MJ = +7.5%) were statistically similar between conditions, and a trend for significance (P = 0.07) was found for trunk LST (MJ-SJ = +7.2%, SJ-MJ = +1.7%). Nonsignificant pre- to post-training changes were observed for lower limb LSTs (MJ-SJ = +0.7%, SJ-MJ = +1.8%). Our data suggest that both sequences are effective for increasing muscle hypertrophy over a short-term RT period; there may be a potentially beneficial hypertrophic effect for the mid-thigh by performing exercises in a manner that progresses from MJ to SJ exercises.

Propuesta de clasificación de las variaciones del músculo bíceps braquial y estudio en una muestra de población colombiana / Proposal of classification for the variations of the biceps brachii muscle and study in a sample of Colombian population

RESUMEN: Las variaciones anatómicas del músculo bíceps braquial en cuanto a la presencia de cabezas accesorias o supernumerarias pueden tener incidencia importante en los diagnósticos clínicos y radiológicos, así como en procedimientos quirúrgicos. La ausencia de una clasificación adecuada para las variaciones del músculo bíceps braquial y los hallazgos del presente estudio le permitieron a los autores presentar una propuesta de clasificación basada en el número de cabezas accesorias y en el origen de ellas. El objetivo del estudio fue determinar la frecuencia con que se presentan variaciones en el número de cabezas accesorias y proponer una clasificación para las variaciones del músculo bíceps braquial. En el estudio de tipo descriptivo, de corte transversal, se analizaron 90 brazos de 46 cadáveres colombianos. Se encontró una alta frecuencia (19,6 %) en las variaciones del músculo, 4,3 % bilateralmente y 15,2 % unilateralmente. En los 11 brazos (12,2 %) que presentaron la variación del músculo, la presencia de una sola cabeza accesoria fue la más alta (81,8 %), siendo el origen más frecuente en ellas el clasificado por los autores como 3b, 3 para la ubicación inferior medial y b para el intervalo entre la inserción del músculo coracobraquial y el origen del músculo braquial. Por lo detallado de la clasificación propuesta, se recomienda su uso cuando se reporten casos de variaciones anatómicas del músculo bíceps braquial. En los cadáveres de la población colombiana estudiados se encontró una alta frecuencia para la presencia de cabezas accesorias de este músculo, que amerita ser conocida por el personal médico.

SUMMARY: The anatomical variations of the biceps brachii muscle in relation to the number of supernumerary or accessory bellies may have important incidence in clinical and radiological diagnoses, as well as in surgical procedures. The absence of an appropriate classification for the variations that the biceps brachii muscle can present and the findings of the present study, allowed the authors to present a classification proposal based on the number of accessory bellies and their origin. The study aimed to determine with which frequency the variations in the number of accessory bellies of the biceps brachii muscle are present, and to propose a classification for these variations. In the crosssectional, descriptive study 90 arms of 46 Colombian cadavers were analyzed. A high frequency (19.6 %) in the variations of the muscle was found, 4.3 % bilaterally and 15.2 % unilaterally. In the 11 arms (12.2 %) that presented the variation, the presence of only one accessory belly was the highest frequency (81.8 %), being the most frequent origin for them the one classified by the authors as 3b, 3 for the inferomedial situation and b for the interval between the insertion of the coracobrachii muscle and the origin of the brachii muscle. Because the classification proposed is very detailed, its use is recommended whenever cases of biceps brachii muscle variations are reported. In the cadavers of the Colombian population studied, a high frequency was found for the presence of supernumerary or accessory heads of this muscle, which deserves to be known by medical professionals.

Prevalencia de cabeza accesoria (humeral) del músculo bíceps braquial: revisión de la literatura / Prevalence of accessory head (humeral) of the biceps brachii: literature review

Las variaciones anatómicas del miembro superior son frecuentes. El músculo bíceps braquial está considerado como uno de los músculos que más variaciones presenta, sobre todo en cuanto al número y morfología de sus cabezas. Su importancia excede lo meramente descriptivo teniendo relevancia clínica y quirúrgica. El objetivo de este trabajo consistió en investigar y revisar la literatura en relación a la prevalencia de la cabeza accesoria del músculo bíceps braquial, su irrigación e inervación así como variaciones anatómicas asociadas. Además se incorporó información de nuestro grupo de investigación, basado en la disección cadavérica de 20 cadáveres adultos formolizados, entre los meses de febrero del 2013 a diciembre del 2016, en la Cátedra de Anatomía Descriptiva y Topográfica de la Facultad de Ciencias Médicas de la Universidad Nacional de Asunción, Paraguay. Se realizó el hallazgo de un caso de cabeza accesoria del músculo bíceps braquial de origen humeral en el brazo derecho de un cadáver de sexo masculino que se originaba en el tercio medio de la cara anteromedial del húmero entre la inserción del coracobraquial y el origen del braquial, representando el 5 % de la población estudiada. Su inserción se dio en la superficie posterior del tendón terminal del músculo, no fueron encontradas otras variaciones asociadas. La variación descripta se ubica entre las más frecuentes del miembro superior. Si bien pueden acompañarse de otras variaciones musculares y vasculonerviosos esto no aconteció en el caso presentado. Su presencia daría mayor fuerza a la acción muscular. Su conocimiento tiene importancia clínica y quirúrgica. La cabeza humeral descripta se presenta en su forma más frecuente, es decir en un varón, en el lado derecho y originándose de la cara anteromedial del cuerpo del húmero. Todas sus cabezas incluido la accesoria estaba inervada por el nervio musculocutáneo. No fueron encontradas otras variaciones anatómicas asociadas tanto musculares como vasculonerviosas.

Anatomical variations of the upper limb are frequent. The biceps brachii is considered as one of the muscles that has the most variations, especially in the number and morphology of their heads. Its importance exceeds the merely descriptive having clinical and surgical relevance. The aim of this study was to investigate and review the prevalence of the accessory head of the biceps brachii muscle, its irrigation and innervation as well as associated anatomical variations. Also we add information based on the cadaveric dissection of 20 adult cadavers formolated from February 2013 to December 2016 in the Chair of Descriptive and Topographic Anatomy of the Faculty of Medical Sciences of the National University of Asuncion, Paraguay. A case of accessory head of the biceps brachii of humeral origin was found in the right arm of a male cadaver that originated in the middle third of the anteromedial surface of the shaft of the humerus between the insertion of the coracobrachial and the origin of the brachial, representing 5 % of the studied population. Its insertion occurred on the posterior surface of the terminal tendon of the muscle, no other associated variations were found. The variation described is among the most frequent of the upper limb. Although they can be accompanied by other muscular and vasculonerviosos variations, this did not happen in the presented case. Their presence would give greater force to the muscular action. Their knowledge is of clinical and surgical importance. The humeral head described is presented in its most frequent form, in a male, in the right side and originating from the anteromedial surface of the shaft humerus. All their heads including the accessory was innervated by the musculocutaneous nerve. No other anatomical variations associated with both muscular and vasculonerviosas were found.

Ultrasound imaging in women's arm flexor muscles: intra-rater reliability of muscle thickness and echo intensity

ABSTRACT Background Different ultrasound parameters have been frequently used to assess changes associated with training, aging, immobilization, and neuromuscular diseases. However, an exploratory reliability analysis of the echo intensity (EI) and muscle thickness (MT) of the forearm flexors is scarce, especially in women. Objective The purpose of the present study was to determine the intra-rater reliability of MT and EI assessed by ultrasound in young women. Method Ultrasonographic MT and EI were acquired in the forearm flexors of 41 young women (22±2 yrs). Reliability was calculated using intraclass correlation coefficient (ICC2,1), standard error of measurement (SEM), coefficient of variation (CV), smallest detectable change (SDC), and Bland and Altman plot analysis. Results ICC values for MT and EI were 0.88 (95% CI: 0.78-0.93). The SEM and CV values were lower than 10%. Bland and Altman analysis revealed that ultrasound mean differences were 0.27 mm (Limits of Agreement - LOA 95%: - 2.6 to 3.2 mm) and -0.09 a.u. (LOA 95%: - 10.9 to 10.7 a.u.). Conclusion MT and EI assessed by ultrasonography in young women appear to be reliable and may be used to monitor changes in muscle mass induced by strength training when these changes exceed the precision of ultrasound.

Cabeza supernumeraria del músculo biceps brachii / Supernumerary head of musculus biceps brachii

Resumen La variable más común del músculo biceps brachii es la presencia de cabezas supernumerarias. El objetivo del presente reporte de caso es describir la presencia de una tercera cabeza del músculo biceps brachii y su significancia clínica. Las variaciones anatómicas descritas fueron encontradas durante una disección de rutina realizada en el laboratorio de morfología de la Universidad de Pamplona en dos cadáveres masculinos, embalsamados, de 75 y 59 años de edad, respectivamente. Las medidas fueron tomadas usando un calibrador Vernier. Los detalles topográficos de las variaciones fueron examinados, registrados y fotografiados. Han sido descritas compresiones de la arteria braquial, nervio mediano, nervio musculocutáneo entre las cabezas supernumerarias del músculo biceps brachii, su conocimiento es de interés para clínicos, especialistas y profesionales de la salud, en aras de lograr diagnósticos, procedimientos y rehabilitaciones más seguras y eficientes.

Abstract The most common variable of the muscle biceps brachii is the presence of supernumerary heads. The aim of this case report is to describe the presence of a third head of the muscle biceps brachii and its clinical significance. The anatomical variations described were found during routine dissection conducted in the laboratory of Morphology of the University of Pamplona in two male cadavers, embalmed of 75 and 59 years respectively. Measurements were taken using a Vernier caliper. Topographic details of the variations were examined, recorded and photographed. They have been described compression of the brachial artery, median nerve, musculocutaneous nerve between the supernumerary heads of muscle biceps brachii, your knowledge is of interest to clinicians, specialists; and health professionals in order to achieve diagnoses, procedures and safer and efficient rehabilitations.

Two unreported cartilagines sesamoidea in the elbow of the dog / Dos cartílagos sesamoideos no reportados en el codo del perro

Two unreported sesamoid cartilages were found inside tendon of insertion of both muscle biceps brachii and muscle brachialis in the dog. This find adds remarkable facts envolving Anatomy, Comparative Anatomy and Clinic and Biomechanics of the elbow joint in the dog. Statistics also emphasize the importance of traumatological incidences on elbow joint in veterinary.

Dos cartílagos sesamoideos no reportados se encontraron en el interior del tendón de inserción de los músculos bíceps braquial (M. Biceps brachii) y Braquial (M. Brachialis) en el perro. Este hallazgo se suma a importantes hechos que comprometen la Anatomía, Anatomía Comparada, Clínica y Biomecánica de la articulación del codo en el perro. Además, la casuística veterinaria también hace hincapié en importantes incidencias traumatológicas en dicha articulación.

Expression of MuRF1 and MAFbx in donor and recipient muscles after musculocutaneous nerve transection and partial pectoralis major muscle transfer for reconstruction of elbow flexion in rats / Expresión de MuRF1 y MAFbx en músculos donantes y receptores después de transección del nervio musculocutáneo y transferencia parcial del músculo pectoral mayor para la reconstrucción de flexión de codo en ratas

The expression of MuRF1 and MAFbx in a denervated muscle has previously been studied. However, the expression of MuRF1 and MAFbx in the recipient and donor muscles after muscle transfer for reconstruction of joint function has not been sufficiently investigated. Forty-two adult Sprague-Dawley rats were divided into 7 groups: normal, 1 w post-, 2 w post-, and 4 w post-musculocutaneous nerve transection; and 1 w post-, 2 w post-, and 4 w post-reconstruction of elbow flexion. Muscle wet weights were assessed, and MuRF1 and MAFbx mRNA expressions were detected by polymerase chain reaction. The length of the oblique part of the pectoralis major of an SD rat is sufficient for suture to the insertion of the biceps brachii tendon. The muscle wet weight and the wet weight retention rate of the biceps brachii continued to decline after musculocutaneous nerve transection and a gradual increase was noted after the oblique part of the pectoralis major was transferred for reconstruction of elbow flexion. The oblique part of the pectoralis major showed a decrease of only 2­6%. The upregulated expression of MuRF1 and MAFbx in the biceps brachii reached a peak 2 w after denervation and 1 w after elbow flexion reconstruction, with an increase of 15% and 4%, respectively. This was followed by downregulation; however, the expression had not normalized at postoperative 4 w. The increased expression of MuRF1 (17%) and MAFbx (1%) in the oblique part of the pectoralis major at postoperative 1 w had decreased to below normal levels at postoperative 4 w. The transfer of the oblique part of the pectoralis major for elbow flexion reconstruction after musculocutaneous nerve transection can downregulate the expression of MuRF1 and MAFbx in the recipient muscle and causes only transient damage to the donor muscle in rats.

La expresión de MuRF1 y MAFbx en un músculo denervado ha sido estudiada previamente. Sin embargo, la expresión de MuRF1 y MAFbx en los músculos receptores y donantes después de la transferencia del músculo para la reconstrucción de la función articular no se ha investigado lo suficiente. Cuarenta y dos ratas adultas Sprague-Dawley fueron divididas en 7 grupos: normales, 1 semana post-, 2 semanas post- y 4 semanas post-transección del nervio musculocutáneo; y 1 semana post-, 2 semanas post-, y 4 semanas post-reconstrucción de la flexión del codo. Se evaluó el peso de los músculos húmedos, y las expresiones de MuRF1 y MAFbx mRNA fueron detectadas a través de reacción en cadena de la polimerasa. La longitud de la parte oblicua del músculo pectoral mayor de una rata Sprague-Dawley es suficiente para realizar la sutura en la inserción del tendón de músculo bíceps braquial. El peso húmedo del músculo bíceps braquial y su tasa de retención siguieron disminuyendo después de la sección del nervio musculocutáneo y un aumento gradual se observó después de la transferencia de la parte oblicua del músculo pectoral mayor para la reconstrucción de la flexión del codo. La parte oblicua del músculo pectoral mayor mostró una disminución de sólo 2-6%. La expresión regulada por incremento de MuRF1 y MAFbx en el bíceps braquial alcanzó un peak 2 semanas después de la denervación y 1 semana después de la reconstrucción de la flexión del codo, con un incremento del 15% y el 4%, respectivamente. Esto fue seguido por un regulación en baja. Sin embargo, la expresión no se normalizó en el postoperatorio de las 4 semanas. El aumento de la expresión de MuRF1 (17%) y MAFbx (1%) en la parte oblicua del músculo pectoral fue mayor en el postoperatorio de 1 semana, mientras que se encontró por debajo de los niveles normales en el postoperatorio de 4 semanas. La transferencia de la parte oblicua del músculo pectoral mayor para la reconstrucción de la flexión del codo después de la sección del nervio musculocutáneo puede regular a la baja la expresión de MuRF1 y MAFbx en el músculo receptor y provocar solo un daño transitorio en el músculo donado en ratas.

Histochemistry profile of the biceps brachii muscle fibres of capuchin monkeys (Cebus apella, Linnaeus, 1758) / Perfil histoquímico das fibras do músculo bíceps braquial do macaco-prego (Cebus apella, Linnaeus, 1758)

A general analysis of the behaviour of “Cebus” shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.

Uma análise geral do comportamento do “Cebus apella” mostra que este primata quando desloca para se alimentar ou realizar outra atividade apresenta diferentes maneiras de locomoção. Estas informações mostram que o músculo bíceps braquial deste animal é usado freqüentemente nas suas atividades de locomoção, mas deve ser lembrado ainda que este músculo é usado também para desenvolvimento de outras atividades como esconder-se, procurar objetos, vasculhar arboredos, além de cavar o chão. Considerando-se o exposto acima decidiu-se pesquisar as características histoenzimológicas do músculo bíceps braquial do macaco-prego com o objetivo de comparar se este músculo esta melhor adaptado para funções posturais ou fásicas. As amostras foram retiradas das regiões superficiais e profundas; inserções proximais (medial e lateral) e distal de seis macacos-prego machos e adultos, os quais foram submetidos às reações de m-ATPase, NADH-Tr. Baseado nos resultados das reações, as fibras foram classificadas em Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) e Slow Twitch (SO). Quanto à área dos diferentes tipos de fibras, os resultados encontrados foram semelhantes em todas as amostras estudadas, e as fibras de contração rápida foram sempre maiores do que as de contração lenta (FG=FOG>SO). Os dados obtidos sobre a frequência foram: nas três regiões superficiais estudadas FOG=FG>SO; nas regiões profundas das inserções proximais FOG=FG=SO e na inserção distal FOG>FG=SO. Baseado nestes dados pode-se concluir que o músculo bíceps braquial do macaco-prego está bem adaptado tanto para atividades posturais como fásicas.

Histochemistry profile of the biceps brachii muscle fibres of capuchin monkeys (Cebus apella, Linnaeus, 1758)

A general analysis of the behaviour of Cebus shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.

Uma análise geral do comportamento do Cebus apella mostra que este primata quando desloca para se alimentar ou realizar outra atividade apresenta diferentes maneiras de locomoção. Estas informações mostram que o músculo bíceps braquial deste animal é usado freqüentemente nas suas atividades de locomoção, mas deve ser lembrado ainda que este músculo é usado também para desenvolvimento de outras atividades como esconder-se, procurar objetos, vasculhar arboredos, além de cavar o chão. Considerando-se o exposto acima decidiu-se pesquisar as características histoenzimológicas do músculo bíceps braquial do macaco-prego com o objetivo de comparar se este músculo esta melhor adaptado para funções posturais ou fásicas. As amostras foram retiradas das regiões superficiais e profundas; inserções proximais (medial e lateral) e distal de seis macacos-prego machos e adultos, os quais foram submetidos às reações de m-ATPase, NADH-Tr. Baseado nos resultados das reações, as fibras foram classificadas em Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) e Slow Twitch (SO). Quanto à área dos diferentes tipos de fibras, os resultados encontrados foram semelhantes em todas as amostras estudadas, e as fibras de contração rápida foram sempre maiores do que as de contração lenta (FG=FOG>SO). Os dados obtidos sobre a frequência foram: nas três regiões superficiais estudadas FOG=FG>SO; nas regiões profundas das inserções proximais FOG=FG=SO e na inserção distal FOG>FG=SO. Baseado nestes dados pode-se concluir que o músculo bíceps braquial do macaco-prego está bem adaptado tanto para atividades posturais como fásicas.

Third head of biceps brachii muscle, associated with musculocutaneous and median nerve bilateral communication and with a communicating branch between median nerve roots / Tercera cabeza del músculo bíceps braquial asociada a la comunicación bilateral de los nervios musculocutáneo y mediano y a un ramo comunicante entre las raíces del nervio mediano

Both biceps brachii muscle anatomical variations and the presence of communicating branches between the musculocutaneous nerve and the median nerve are common, and have clinical significance due to their connections and vulnerability. A case found during a routine dissection of the upper limb of a male cadaver is described, in which unilateral presence of a third head of the biceps brachii muscle coexists associated to a bilateral communication of the musculocutaneous nerve with the median nerve, and a unilateral communicating branch between the roots of median nerve. The morphological features and the prevalence of the case are presented, besides the discussion of its clinical significance.

Tanto las variaciones anatómicas del músculo bíceps braquial como la presencia de ramos comunicantes entre los nervios musculocutáneo y mediano son frecuentes y tienen importancia clínica, debido a sus relaciones y vulnerabilidad. Se describe un caso encontrado durante una rutina de disección de los miembros superiores de un cadáver masculino, en el que coexiste la presencia unilateral de una tercera cabeza del músculo bíceps braquial asociada a una comunicación bilateral entre los nervios musculocutáneo y mediano junto a un ramo comunicante unilateral entre las raíces del nervio mediano. Se presentan sus características morfológicas, su prevalencia y se discute su importancia clínica.

Múltiples Variaciones Musculares y Neurovasculares en los Miembros Superiores: Presentación de Caso / Multiple Muscle and Neurovascular Variations in the Upper Limbs: Case Report

Se presenta un raro caso de múltiples variaciones en los miembros superiores de un espécimen cadavérico de 45 años de género masculino, del laboratorio de morfología de la Universidad Industrial de Santander (Bucaramanga-Colombia). Se observó variaciones musculares (presencia bilateral de cabezas adicionales del bíceps braquial y del musculo flexor largo del pulgar, agenesia del palmar largo derecho), nerviosas (anastomosis entre mediano y nervio musculocutáneo, y entre ulnar y mediano al nivel palmar superficial). Adicionalmente, presentó el origen de la arteria radial izquierda desde el segmento superior de la braquial. Estas diversas expresiones morfológicas determinan relevantes implicaciones clínicas y deben tenerse en cuenta en los diferentes abordajes quirúrgicos de los miembros superiores.

It is presented a rare case of multiple variations in the upper limbs of a 45 years old male cadaver specimen, ownership of the morphology laboratory of the Universidad Industrial de Santander (Bucaramanga, Colombia). Muscle variations were observed (presence of both additional heads of the biceps brachii and the flexor pollicis longus, agenesis of right palmaris longus), nervous variations (anastomosis between median and musculocutaneous nerve and between ulnar and median at superficial palmar level). Additionally it presented the radial artery origin from upper left segment of the brachial artery. These various morphological expressions determine relevant clinical implications and should be taken into account in the various surgical approaches to the upper limbs.

Biceps Brachii Muscle Innervation Zone Location in Healthy Subjects Using High-Density Surface Electromyography / Ubicación de la Zona de Inervación del Músculo Bíceps Braquial en Sujetos Sanos Mediante Electromiografía de Superficie de Alta Densidad

Among the sequelae of central nervous system injury is spasticity which is difficult to manage in rehabilitation. Current treatments consider the administration of the botulinum toxin. However, results have proved highly variable in terms of effectiveness, attributable to the distance between the injection site and the innervations-zone (IZ). High Density sEMG (HDsEMG) has been used to gather information about muscle physiology and for location of the IZ. The aim of this study was to characterize the IZ of the biceps brachii muscle in healthy subjects during isometric contraction. We assessed the biceps brachii muscle of twenty healthy subjects (n=20) using a 64 surface electrodes matrix. The average location of the IZ was 34 percent distal to the line between the cubital fossa and the anterior acromion.

Entre las secuelas de lesiones del Sistema Nervioso Central se encuentra la espasticidad, la cual es de difícil manejo terapéutico. Los tratamientos actuales de la espasticidad consideran la administración de la toxina botulínica. Sin embargo, los resultados de su aplicación han sido muy variables en términos de eficacia, atribuible a las distintas distancias entre el lugar de inyección y la zona de inervación (ZI). La EMG de alta densidad se ha utilizado para recolectar información acerca de la fisiología muscular y para localizar la ZI. El objetivo de este estudio fue describir la ubicación de la ZI del músculo bíceps braquial en sujetos jóvenes sanos, durante una contracción isométrica. Evaluamos el músculo bíceps braquial en 20 sujetos sanos usando una matriz de 64 electrodos. El promedio de localización de la ZI fue de 34 por ciento en el sentido distal de la línea trazada entre la fosa cubital y el acromion anterior.

Incidence of humeral head of biceps brachii muscle: anatomical insight / Incidencia de la cabeza humeral del músculo bíceps braquial - visión anatómica

Biceps brachii is stated as one of the muscles that shows most frequent anatomical variations. Its most commonly reported anomaly is the presence of an accessory fascicle arising from the humerus which is termed as the humeral head of biceps brachii. Evidence shows a clear racial trend in the incidence of the humeral head of biceps brachii. Therefore, detailed knowledge of this variation in different populations is important for surgical interventions of the arm, nerve compression syndromes and in unexplained pain syndromes in the arm or shoulder region. The goal of this study was to elucidate the incidence and morphological features of this muscle in an adult Sri Lankan population. Upper extremities of the total of one hundred thirty five cadavers were dissected and studied for the presence of accessory heads of the biceps brachii muscle. The proximal and distal attachments of the humeral heads as well as their cranio-caudal, antero-posterior and medio-lateral dimensions were recorded. The incidence of humeral head of biceps brachii was found to be 3.7 percent. In all cases, it was found unilaterally and only in male subjects. The humeral head originated from the antero-medial aspect of the humeral shaft and descended and merged with the other two heads to form a common tendon. The results of the present study further highlight the racial variations in the incidence of humeral head of biceps brachii among Sri Lankans. Knowledge of the occurrence of humeral head of biceps brachii may facilitate preoperative diagnosis as well as the surgical procedures of the upper limb thus avoiding iatrogenic injuries.

El músculo bíceps braquial se conoce como uno de los músculos que muestra las variaciones anatómicas más frecuentes. Su anomalía más común es la presencia de un fascículo accesorio proveniente del húmero, que se denomina cabeza humeral del músculo bíceps braquial. La evidencia muestra una clara tendencia racial en la incidencia de la cabeza humeral del músculo bíceps braquial. El conocimiento acabado de esta variación, en las diferentes poblaciones, es importante para las intervenciones quirúrgicas del brazo, en los síndromes de compresión nerviosa y en los síndromes de dolor inexplicable en la región del brazo o del hombro. El objetivo de este estudio fue determinar la incidencia y las características morfológicas de este músculo en una población adulta de Sri Lanka. Fueron estudiados los miembros superiores en 135 cadáveres, disecados para evaluar la presencia de las cabezas del músculo bíceps braquial accesorio. Fueron registrados el origen e inserción de la cabeza humeral del músculo bíceps braquial, así como su dimensión cráneo-caudal, anteroposterior y mediolateral. La incidencia de la cabeza humeral del músculo bíceps braquial se encontró en el 3,7 por ciento de los miembros estudiados. En todos los casos, su presencia era unilateral y sólo presente en hombres. La cabeza humeral se originó en la región antero-medial de la diáfisis del húmero, descendió y se fusionó con las otras dos cabezas para formar un tendón común. Los resultados de este estudio resaltan aún más las variaciones raciales en la incidencia de la cabeza humeral del músculo bíceps braquial, entre los habitantes de Sri Lanka. El conocimiento de la presencia de la cabeza humeral del músculo bíceps braquial puede facilitar el diagnóstico preoperatorio, así como los procedimientos quirúrgicos del miembro superior, evitando las lesiones iatrogénicas.

Entrapment of the median nerves and brachial arteries in the lower arms bilaterally and additional origin of biceps brachii muscle: case report / Compresión bilateral del nervio mediano y de la arteria braquial en la parte distal del brazo y origen adicional del músculo bíceps braquial: reporte de caso

Neuro-vascular entrapments associated with variations observed in the origins of muscles in the arm are not uncommon. Though additional heads of biceps brachii muscle and extra fibres of brachialis muscles have been demonstrated earlier, bilateral additional heads of the biceps are rarely seen, especially with entrapment of the median nerve and the brachial arteries in both the arms. The present study reports conspicuous heads of the biceps brachii originating extensively from the medial inter-muscular septum, sharing its origin with the brachialis muscle. The extra origins of the muscle formed long musculo-aponeurotic tunnels. The tunnels measured eight centimeters in length extending from the lower arm to the cubital-fossa. Both the median nerve and the brachial arteries passed through the tunnel. The lower aspect of the left tunnel exhibited origins of fibres belonging to the superficial flexors of the forearm. The neuro-vascular structures did not give any branches in the tunnel. Awareness of such variations can aid clinicians in diagnosing and treating such neuropathies and vascular compromise.

No es infrecuente observar atrapamientos neuro-vasculares asociados con variaciones en el origen de los músculos del brazo. A pesar de haberse observado cabezas adicionales del músculo bíceps braquial y fibras extra del músculo braquial raramente estas cabezas adicionales bilaterales han sido causantes de la compresión del nervio mediano y de la arteria braquial. En este trabajo presentamos las cabezas del músculo bíceps braquial originándose en gran parte en el tabique intermuscular medial compartiendo su origen con el músculo braquial. Los orígenes adicionales del músculo forman largos túneles músculo fasciales. Los túneles miden 8 cm de longitud, y se extienden desde la parte inferior del brazo hasta la fosa cubital. Tanto el nervio mediano como la arteria braquial pasan por el túnel. La parte inferior del túnel izquierdo dio origen a fibras pertenecientes al músculo flexor superficial del antebrazo. Las estructuras neurovasculares no otorgaron colaterales en el túnel. El conocimiento de estas variaciones puede ayudar a los clínicos en el diagnóstico y el tratamiento de neuropatías y compromiso vascular.

Origin of the tendon of the long head of the biceps brachii muscle and its relationship with glenoid labrum in human foetuses / Origen del tendón de la cabeza larga del bíceps braquial y sus relaciones con el labro glenoideo en fetos humanos

We dissected the shoulders of 20 human foetuses to anatomical study. The purpose of this study was to characterize the anatomical origin of the long head tendon of the muscle biceps brachii (LHBBT) in human foetuses and its relationships with the glenoid labrum of the scapula. The results had shown that in approximately 95 percent of the cases the tendon of the long head of the biceps brachii inserts in the region of the glenoid labrum. This origin seems to form, together with the glenoid labrum, an anatomical complex. We conclude that the almost totality of the LHBBT was originated in the glenoidal labrum. For us, this furthermore reinforce the importance and necessity of better clarifying the anatomical and clinical implications of the biceps/labrum complex.

Fueron disecados los hombros de 20 fetos humanos con el propósito de hacer un estudio anatómico. El objetivo de este estudio fue cdeterminar el origen del tendón de la cabeza larga del músculo bíceps braquial en fetos humanos y sus relaciones con el labro glenoideo. Los resultados demostraron que, en cerca del 95 por ciento de los casos, el tendón de la cabeza larga del músculo bíceps braquial estaba originándose en la región del labro glenoideo. Este origen parece formar junto, con el labro glenoideo, un complejo anatómico. Concluimos que casi todos de los tendones del músculo bíceps braquial están insertados en el labro glenoideo. Esto es importante conocer para una mejor clarificación de las implicaciones clínico-anatómicas del complejo del bíceps/labro.