Evaluation of movements of lower limbs in non-professional ballet dancers: hip abduction and flexion.

BACKGROUND: The literature indicated that the majority of professional ballet dancers present static and active dynamic range of motion difference between left and right lower limbs, however, no previous study focused this difference in non-professional ballet dancers. In this study we aimed to evaluate active movements of the hip in non-professional classical dancers. METHODS: We evaluated 10 non professional ballet dancers (16-23 years old). We measured the active range of motion and flexibility through Well Banks. We compared active range of motion between left and right sides (hip flexion and abduction) and performed correlation between active movements and flexibility. RESULTS: There was a small difference between the right and left sides of the hip in relation to the movements of flexion and abduction, which suggest the dominant side of the subjects, however, there was no statistical significance. Bank of Wells test revealed statistical difference only between the 1st and the 3rd measurement. There was no correlation between the movements of the hip (abduction and flexion, right and left sides) with the three test measurements of the bank of Wells. CONCLUSION: There is no imbalance between the sides of the hip with respect to active abduction and flexion movements in non-professional ballet dancers.

Cardiac baroreflex is already blunted in eight weeks old spontaneously hypertensive rats.

BACKGROUND: The literature did not evidence yet with which age spontaneously hypertensive rats (SHR) start to present baroreflex reduction. We endeavored to evaluate the baroreflex function in eight-week-old SHR. METHODS: Male Wistar Kyoto (WKY) normotensive rats and SHR aged eight weeks were studied. Baroreflex was calculated as the variation of heart rate (HR) divided by the mean arterial pressure (MAP) variation (DeltaHR/DeltaMAP) tested with a depressor dose of sodium nitroprusside (SNP, 50 microg/kg) and with a pressor dose of phenylephrine (PHE, 8 microg/kg) in the right femoral venous approach through an inserted cannula in the animals. Significant differences for p < 0.05. RESULTS: Baseline MAP (p < 0.0001) and HR (p = 0.0028) was higher in SHR. Bradycardic peak was attenuated in SHR (p < 0.0001), baroreflex gain tested with PHE was also reduced in the SHR group (p = 0.0012). PHE-induced increase in MAP was increased in WKY compared to SHR (p = 0.039). Bradycardic reflex responses to intravenous PHE was decreased in SHR (p < 0.0001). CONCLUSION: Eight weeks old SHR already presents impairment of the parasympathetic component of baroreflex.

Estudo eletromiográfico da porçäo superior dos músculos trapézio e grande dorsal em movimentos contra-resistência do braço / Electromyographic study of the upper portion of the trapezius and latissimus dorsi muscles in movements against resistence of the arm

A porçao superior dos músculos trapézio e grande dorsal foi analisada em 20 indivíduos adultos do sexo masculino, com idade entre 18 e 30 anos em movimentos contra-resistência do braço. Foram utilizados em eletromiógrafo TECA TE 4 de dois canais e eletrodos de superfície da marca HEWLETT PACKARD. Observou-se que o músculo trapézio apresentou atividade predominante na abduçao a 0, na abduçao e flexao a 90 e 180, enquanto que o músculo grande dorsal foi principalmente ativo na aduçao a 180, 9O e O, como também, na extensao a 0.

Estudo eletromiográfico da porçäo superior dos músculos trapézio e grande dorsal em movimentos livres do braço / Electromyographic study of the upper portion of the trapezius and latissimus dorsi muscles in free movements of the arm

A porçao superior dos músculos trapézio e grande dorsal foi analisada em 20 indivíduos adultos do sexo masculino, com idade entre 18 e 30 anos em movimentos livres do braço. Foram utilizados um eletromiógrafo TECA TE 4 de dois canais e eletrodos de superfície da marca HEWLETT PACKARD. Observou-se que o trapézio foi ativo na abduçao, aduçao, flexao, circunduçao e o grande dorsal, na flexao e circunduçao.

Electromyographic behavior of the biceps femoris muscle during knee extension and flexion performed on the leg press

The biceps femoris was analyzed in 10 volunteers during knee extension and flexion with the foot in normal plantar flexion and dorsal flexion positions. Hewlett-Packard surface electrodes, an electromyographic signal amplifier, a computer equipped with an A/D conversion plaque (Model CAD 10/26), software especially designed to record and analyze the signals, Horizontal Leg Press equipped with four platforms for the feet (2 superior and 2 inferior) which acted as a support for the movements and electrogoniometers were used. The biceps femoris muscle acted as an antagonist in knee extension, primary motor of hip extension and flexor of knee joint. The upper platforms of the Leg Press required the strongest activity from the biceps femoris in relation to the lower platforms. As for bilateral action, the activity of the right biceps femoris predominated over the contralateral muscle action in all plataforms. Foot positions did not interfere in biceps femoris action.