Palpation of the lateral bands of the extensor apparatus of the fingers. Anatomy of a neglected clinical finding.

This study aimed to determine by ultrasonography, and cadaveric dissection, whether the firm cords felt by palpation at the sides of the proximal phalanx (PP), actively flexing, and extending the proximal interphalangeal (PIP) joint while keeping the metacarpophalangeal (MCP) joint extended are the lateral bands (LBs) of the extensor apparatus. If so, palpation of the LBs could help evaluate hand conditions that impact the digits' intrinsic muscles. To this end, the PP of the middle and ring fingers of the dominant hand of seven subjects were studied by palpation on both sides. Ultrasonography (US) was performed with a hockey-stick transducer placed on the ulnar side. Five cadaveric hands were dissected, exposing the dorsal extensor apparatus. On palpation, a firm cord was consistently felt at the PP's sides in all subjects. These cords moved widely forward on PIP flexion and backward with PIP extension. By US scanning, the cords corresponded to the LBs. However, the forward movement had only a median of 1.8 mm (range 0.7-3 mm) in the middle finger and a median of 1.1 mm (range 0.3-2.7 mm) in the ring finger compared with an estimated 5-10 mm upon palpation. Cadaveric dissection confirmed the forward movement of the LBs in PIP flexion. We concluded that the firm cords felt at the PP sides are the LBs of the extensor apparatus. We confirmed their movement with the active flexion/extension of the PIP joint. Comparing the wide palpatory and the meager US motion, a haptic illusion of motion may be present.

The median nerve consistently drives flexion of the distal phalanx of the ring and little fingers: Interest in finger flexion reconstruction by nerve transfers.

Surgeons believe that in high ulnar nerve lesion distal interphalangeal joint (DIP) flexion of the ring and little finger is abolished. In this article, we present the results of a study on innervation of the flexor digitorum profundus of the ring and little fingers in five patients with high ulnar nerve injury and in 19 patients with a brachial plexus, posterior cord, or radial nerve injury. Patients with ulnar nerve lesion were assessed clinically and during surgery for ulnar nerve repair we confirmed complete lesion of the ulnar nerve in all cases. In the remaining 19 patients, during surgery, either the median nerve (MN) or the anterior interosseous nerve (AIN) was stimulated electrically and DIP flexion of the ring and little fingers evaluated. All patients with high ulnar nerve lesions had active DIP flexion of the ring and little fingers. Strength scored M4 in the ring and M3-M4 in the little finger. Electrical stimulation of either the MN or AIN produced DIP flexion of the ring and little fingers. Contrary to common knowledge, we identified preserved flexion of the distal phalanx of the ring and little fingers in high ulnar nerve lesions. On the basis of these observations, nerve transfers to the AIN may provide flexion of all fingers.

Anatomical study of the A1 pulley: length and location by means of cutaneous landmarks on the palmar surface.

PURPOSE: The objectives of this study were to evaluate palmar surface parameters to identify the exact location of the proximal edge of the flexor tendon A1 pulley relative to the digital palmar crease of the index, middle, ring, and little fingers and to evaluate the length of this pulley. METHODS: We studied 280 fingers on 70 hands from 35 fresh human cadavers, initially by measuring the distance between the digital-palmar and proximal interphalangeal creases (measure A), followed by dissection of the fingers and measurement of the distance between the proximal edge of the A1 pulley and the digital-palmar crease (measure B) and the length of the A1 pulley (measure C). We carried out statistical analysis using Hotelling's multivariate T(2)-test and the paired-samples t-test. RESULTS: We found no statistically significant difference between measures A and B in each finger (p > .05). The mean lengths, in tenths of millimeters, were as follows: measure A: index finger 22.0 mm, middle finger 24.4 mm, ring finger 22.0 mm, and little finger 17.9 mm; measure B: index finger 21.9 mm, middle finger 24.2 mm, ring finger 22.3 mm, and little finger 18.1 mm. The average lengths of the A1 pulley were: index finger 9.8 mm, middle finger 10.7 mm, ring finger 9.6 mm, and little finger 8.1 mm. CONCLUSIONS: The distance between the digital-palmar and proximal interphalangeal creases may be used as a cutaneous landmark on the palmar surface for the exact location of the proximal edge of the A1 pulley in the palm of the hand, thereby ensuring greater safety in surgical procedures such as percutaneous release of trigger finger.

Effects of the myofascial release in diffuse systemic sclerosis.

OBJECTIVE: To improve breathing and functionality of the temporomandibular joint (TMJ) and hands, by increasing the range of motion (ROM), and to reduce the level of pain. METHOD: Twenty myofascial release (MR) sessions in 2002 with assessments (chest expansion, mouth opening, ROM of wrist and fingers). Between the 19th and the 20th session there was a break of 110 days. Every winter, 1-3 sessions have been made. RESULTS: Chest: expansion increased by 3.5 cm and pain was eliminated at the scar from a biopsy; TMJ: an 8mm increase in mouth opening with pain eliminated; hands and fingers: increase of ROM in all joints of fingers and wrists, of up to 100%, reduction in ulcerations and recovery of nail growth. CONCLUSION: The connective tissue affected by diffuse systemic sclerosis (dSSc) is subject to remodeling through MR, receding when the work is interrupted. Resuming the treatment on a regular basis increased the ROM in joints, reduced the effects of the Raynaud Phenomenon and the pain.

Ultrastructural study of the neuromuscular junctions of extensor digitorum longus muscle (M. extensor digitorum longus) of the mice / Estudio ultraestructural de las uniones neuromusculares del músculo extensor largo de los dedos (M. extensor digitorum longus) del ratón

The neuromuscular junction of the extensor digitorum longus muscle of fingers was analyzed in 21 young (three months) and old (from six to 25 months) mice, from both genders. Morphologic changes were found throughout the mouse life, being more frequent and visible with aging. According with the data described in the literature consulted and the observations taken in this research, it becomes clear that a continuous process of morphological remodeling occurs in all neuromuscular ultrastructural junctions of the extensor digitorum longus muscle of fingers, during the life of the animal. Theses changes are characterized by figures of myelin in the cytoplasm of Schwann cells, pleomorphic and multivesiclar bodies, mitochondrias with morphologically altered crests in the axon terminal and degenerated junction folders. Coated vesicles are common in older animals and rare in young animals.

La ultraestructura de las uniones mioneurales del músculo extensor largo de los dedos fue analizada en 21 ratones, jóvenes (tres meses) y viejos (de seis a 25 meses), de ambos sexos. Los cambios morfológicos fueron encontrados en toda la vida del ratón, siendo más frecuentes y visibles en el envejecimiento. Según los datos descritos en la literatura comsultada y las observaciones tomadas en esta investigación, se concluye que un proceso continuo de remodelación morfológica ocurre en todas las uniones mioneurales del músculo extensor largo de los dedos, durante la vida del animal. Tales cambios son caracterizados por figuras de mielina en el citoplasma de las células del neurilema, cuerpos pleomórficos y multivesiculares, mitocondrias con crestas morfologicamente cambiadas y pliegues de unión degeneradas. Las vesículas son comunes en animales más viejos y raras en animales jóvenes.

Características anatómicas del tendón extensor accesorio del dedo anular, procedente del músculo extensor del dedo mínimo / Anatomical characteristics of the accessory extensor tendon of the ring finger, originating from the extensor digiti minimi muscle

El músculo extensor del dedo mínimo es una larga y estrecha lámina muscular que se origina en el epicóndilo lateral del húmero, en el tendón extensor común, insertándose, generalmente, a través de dos cintillas tendinosas, en la expansión extensora del dedo mínimo. A veces, emite un tendón accesorio para el dedo anular.El objetivo del presente estudio fue conocer la incidencia, disposición y trayecto de este tendón accesorio. Se estudiaron 60 piezas de miembros superiores, fijadas en formaldehído al 10 por ciento, correspondientes a cadáveres de individuos brasileños, adultos, de ambos sexos. El tendón accesorio fue encontrado en 7 manos (11,7 por ciento de los casos). La presencia de ese tendón tiene importancia funcional y clínico-quirúrgica, pues en casos de lesiones en el dorso de la mano que afecten a los tendones del músculo extensor de los dedos, este tendón accesorio podría establecerse como una forma alternativa en la recuperación del movimiento de la extensión del dedo anular. Los resultados complementarán el conocimiento anatómico del conjunto de tendones que constituyen el dorso de la mano.

The extensor digiti minimi muscle originates from the posterior aspect of the lateral epicondyle of the humerus from a common tendon for the epicondilar muscles. The muscular belly is long and narrow and runs distally until it joins the ulnar side of a tendon over the radiocarpal articulation. Over the dorsum of the hand, this muscle is represented by a double tendon that insert in the extensor apparatus. Sometimes, these tendons give off an accessory tendon for the ring finger. The objective of this present study was to know the incidence, disposition and course of this accessory tendon. We are study 60 upper limbs from Brazilian adult cadavers of both sexs, fixed in formaldehyde 10%. The accessory tendon of the ring finger was found in 7 hands (11,7% of the cases). The presence of this tendon have functional and surgical importance; in extensor digitorum tendons injuries, this accessory tendon could be an alternative for recuperate the extension movement of the ring finger. Our results will complete the anatomic knowledge over the dorsal tendons of the hand.

Measurement of the flexing force of the fingers by a dynamic splint with a dynamometer.

PURPOSE AND METHODS: In order to determine forces acting upon an articular joint during hand rehabilitation, a dynamic splint was built and connected to a dynamometer (capable of measuring forces in the range 0 - 600 gf). Through trigonometric calculation, the authors measured the flexing force in the proximal interphalangeal joint of the middle finger at 30 degrees, 45 degrees, 60 degrees, and 90 degrees of flexion. Measurements were obtained in a population of 40 voluntary adults, 20 females and 20 males, This flexing force was correlated with age, sex, and anthropometric measures. RESULTS: Force in the flexing tendon is maximal at the start of flexion, and decreases as the angle of joint flexion increases. A relationship was observed between finger length and the magnitude of the force exerted on the tendon: the longer the finger, the greater the force exherted upon the tendon. Force is greater at all the measured angles, (except 30 degrees) in males and in individuals of higher stature, and bigger arm span. CONCLUSIONS: The flexing force can be effectively measured at all flexing angles, that it correlates with a number of different anthropometric parameters, and that such data are likely to open the way for future studies.

Measurement of the flexing force of the fingers by a dynamic splint with a dynamometer

OBJETIVO E MÉTODOS: Em virtude do desconhecimento relativo às forças que atuam em uma articulação durante o processo de reabilitação da mão, foi confeccionada uma órtese dinâmica que, acoplada a um dinamômetro, mediu, através de cálculos trigonométricos, a força (entre 0 a 600gf), flexora na articulação interfalângica proximal do terceiro dedo, a 30º, 45º, 60º e 90º de flexão. Estas medidas foram obtidas, em uma população de 40 adultos voluntários, 20 do sexo feminino e 20 do masculino, e confrontadas com idade, sexo e medidas antropométricas como estatura, envergadura e comprimento do dedo. RESULTADOS: Os resultados do estudo demonstraram que o tendão flexor é submetido à máxima força no início da flexão e que a força no tendão flexor diminui conforme aumenta o grau de amplitude articular. Observou uma relação entre o comprimento do dedo e a magnitude da força exercida no tendão durante a flexão do dedo, sendo que nos dedos mais compridos os tendões são submetidos a forças maiores. Quando comparou a estatura e envergadura com a magnitude da força aplicada no tendão flexor, observou uma relação positiva em todos os graus de flexão estudados, exceto a 30º. O sexo masculino apresentou maior força em todos os graus de amplitude articular. CONCLUSÕES: Conclui que é possível medir a força de flexão transmitida pelos tendões flexores através de uma órtese acoplada a um dinamômetro, que esta força é maior nos indivíduos do sexo masculino, com dedos mais longos, de maior altura e envergadura e que tais dados permitirão o desenvolvimento de futuros trabalhos no campo da reabilitação da mão, auxiliando pacientes portadores de lesões de tendões, retração cicatricial, deformidades e rigidez articular.

Development of anthropomorphic upper limb prostheses with human-like interphalangian and interdigital couplings.

This article presents a model for the couplings of the movements between the phalanges and fingers in a hand when they execute certain functions. It also shows the importance of knowing these couplings, suggests methods for obtaining them, and discusses how to apply them to the construction of artificial upper limbs, highlighting the important mechanical aspects for achieving such a goal. Thus, it gives support for projects of upper limb prosthesis with anthropomorphic characteristics.

Sistema de monitorizaçäo da posiçäo dos dedos durante a manipulaçäo de objetos visando o controle do movimento de preensäo de tetraplégicos / Monitoring system of finger position during object manipulation aiming the control of tetraplegic grasp movement

Para o controle artificial da preensão de tetraplégicos, um dos parâmetros relevantes para a caracterização do movimento é a posição dos dedos em cada instante. Propõe-se no presente trabalho a implementação de um sistema capaz de monitorar este parâmetro durante a manipulação de objetos. O transdutor, propriamente dito, corresponde a uma luva de lycra dotada de um sensor de deslocamento localizado sobre a articulação de interesse, constituindo uma alternativa prática e de baixo custo. Os testes preliminares de calibração mostraram a potencialidade do transdutor como fornecedor do "feedback" de posição mas, também, a necessidade de otimização do sistema visando sua aplicação clínica

Abstract - Finger position is a very important parameter for artificial grasp control of a tetraplegic. This work suggests a system for monitoring this parameter during object manipulation. The transducer is composed by a Jycra glove with a displacement sensor attached to the joint position. lt is a low cost system, being easy to use and cosmetically acceptable. Preliminary tests have shown the transducer potential as a position feedback supplier, but also the need for design improvements towards clinicai application