Fatigue during sustained maximal voluntary contraction of different muscles in humans: dependence on fibre type and body posture.

Nine healthy men, aged between 25 and 35 years, performed sustained maximal voluntary contractions (MVC) of foot plantar, foot dorsal, and finger flexor muscles. Contractions lasted 10 min and were followed by short test contractions at 30% MVC during recovery. Two positions of the working extremity high or low were established by different body postures (supine or sitting).

[Sex- and age-related differences in blood pressure response to local muscular work during noise].

During noise exposure (90 dB [A]) and during local muscular work (30% MVC) combined with noise (90 db [A]) the blood pressure was measured in 20 men and 20 women (20-29 years; 30-39 years). In the group of younger subjects the blood pressure was taken also during the recovery period of 60 minutes. Age- and sex-related differences in blood pressure response were observed not only during noise exposure but also during combined exposure.

[Local muscle work and noise and their effect on the amplitude of the finger pulse].

The finger pulse amplitude of 10 healthy men (aged 20 to 30 years) was measured during noise (70, 80 and 90 dBA) and combined exposure (local muscular work with 30% MVC and noise with 70, 80 or 90 dBA) and during a recovery phase of 60 min. The finger pulse amplitude was reduced only during noise exposure with 90 dBA and was increased during the combined exposures. A continuous decrease of the finger pulse amplitude was observed during the recovery phases.

Force, endurance time, and cardiovascular responses in voluntary isometric contractions of different muscle groups.

A study was made to reinvestigate the general validity of the force/endurance relation of isometric contractions. Relative force development, mean bioelectrical muscle activity and circulatory responses (blood pressure, interbeat interval) during isometric contractions of different muscle groups were compared. 6 men performed maximum isometric contractions of foot plantar- and dorsalflexors and hand flexors lasting 10 minutes.