Classificação e relação anatômica dos tipos de incisura da escápula e sua importância clínica / Classification and anatomical relationship of types of suprascapular notch and its clinical importance

Objetivo - Este estudo anatômico classificou os diferentes tipos de incisura da escápula e estabeleceu a relação entre a incisura e a área total da escápula, evidenciando a clínica apresentada na compressão do nervo supraescapular, o qual tem sua passagem dentro do forame limitado pela incisura e o ligamento transverso superior da escápula. Este é um nervo misto, originário de C5-C6 e frequentemente de C4, seu componente motor supre os músculos supra e infraespinais e seu componente sensitivo as articulações acromioclavicular e glemoumeral. Em atletas de voleibol e basebol há hipertrofia do músculo subescapular e compressão desse nervo. Métodos - Foram analisadas 93 escápulas maceradas e classificadas de acordo com Rengachary et al.4 (1979), onde foi estabelecida a relação entre a área da incisura e a área total da escápula por meio do método de gabarito de papel. Resultados - A incisura da escápula do tipo III foi prevalente (34%), tendo uma pequena área comparando com os outros tipos; a seguida pelo tipo IV (20%); e tipo VI ausente. O valor médio da relação entre a área da incisura da escápula e a área total da escápula foi de 0,3%. Conclusão - As escápulas que possuem incisuras do tipo III foram prevalentes seguidas pelo tipo IV e as do tipo VI ausentes, apresentando, segundo a literatura, maior propensão à gerar uma compressão.

Objective - This anatomical study classify the different types of suprascapular notch and establish the relation between the notch area and the total area of the scapula, showing the clinical presentation in compression of the suprascapular nerve, which has this passage into the foramen bounded by the notch and the superior transverse scapular ligament. This is a mixed nerve, wich originates from C5-C6 and often C4, its motor component supplies the supra and infra espinal muscles and your sensory component the glenoumeral and acromioclavicular joints. In volleyball and baseiball athletes there subscapularis muscle hypertrophy and compression of this nerve. Methods - Ninety three macerated scapula were analyzed and classified according Rengachary et al.4 (1979), where was established the relationship between the notch area and the total area of the scapula through the template paper method. Results - The suprascapular notch of type III was prevalent (34%), with a small area compared to other types; followed by the type IV (20%); and type VI absent. The medium score between the area of the scapular notch and the total area of the scapula was 0,3%. Conclusion - The scapula that have suprascapular notch type III have been prevalent, followed by type IV and type VI was absent, showing, according to literature, a greater propensity to generate a compression.

Electromyographic analysis of the trapezius and the serratus anterior muscles in shoulder and pectoral girdle movements

The upper and lower portions of the trapezius muscle and the 4th, 5th and 6th bundles of the serratus anterior muscle were studied electromyographically during shoulder and pectoral girdle movements, in ten adultmales, aged 18 to 28 years, with no history of shoulder pathology. For this study a Nicolet Electronmyograph and surface electrodes were used. The signals were recorded as root mean square (RMS) values, expressedin microvolts. Wilcoxon and Friedman tests were done to a 5 (per cent) significance level. The results showed that there were no differences in the behaviour of the serratus anterior muscle bundles. In the shoulder abduction and flexion movements, the upper portionof the trapezius acted simultaneously with the serratus anterior muscle. In horizontal abdunction and adduction movements there was no prevalence of any of the muscles studied. In shoulder elevation, the upper portion of the trapezius muscle showed preponderant activity over its lower portion and over the serratus anterior muscle bundles. In the shoulder depression the activity of the lower portion of the trapezius muscle predominated over the serratus anterior muscle bundles, and the least activity was exhibited by the upper portion of the trapezius muscle.