caa a22 4500 469054905 CHVBK 20180323132840.0 cr unu---uuuuu 170328e19920301xx s 000 0 eng 10.1007/BF00705077 doi (NATIONALLICENCE)springer-10.1007/BF00705077 Intramuscular pressures during exercise: an evaluation of a fiber optic transducer-tipped catheter system [Elektronische Daten] [Albert Crenshaw, Jorma Styf, Alan Hargens] Summary: The efficacy of a modified fibre optic transducer-tipped catheter system for measuring intramuscular pressures during exercise was determined. A microcapillary infusion technique using a catheter was employed as the standard of comparison due to its established dynamic properties. Pressures were measured in the tibialis anterior muscle of six healthy adults at rest before exercise, during isometric and concentric exercise, and at rest after exercise. The fibre optic system measured contraction pressures equal to the microcapillary infusion technique during all phases of the exercise protocols but recorded a lower relaxation pressure during isometric exercise and a lower rest pressure following 20 min of concentric exercise. Negative relaxation pressures were recorded by the fibre optic system for two subjects during continuous concentric exercise. It is hypothesized that a piston effect, due to the sliding of muscle fibres at the catheter tip following a contraction, rendered falsely low pressures during relaxation and that this artefact was reflected in the subsequent rest pressure following exercise. The larger volume (157 mm3) and area (3.49 mm2) of the fibre optic catheter in the muscle made it more prone to this effect than the conventional catheter (39 mm3 and 0.87 mm2, respectively). The fibre optic system may be preferred when recording the musclecontraction pressures during complex limb movements but should not be used when assessing the relaxation pressures or the pressure at rest following exercise. Springer-Verlag, 1992 Concentric exercise nationallicence Isometric exercise nationallicence Muscle contraction pressure nationallicence Muscle relaxation pressure nationallicence Human tibialis anterior muscle nationallicence Crenshaw Albert Department of Anatomy, University of Umeå, S-90187, Umeå, Sweden aut Styf Jorma Department of Orthopaedics, East Hospital, University of Gothenburg, S-41685, Gothenburg, Sweden aut Hargens Alan NASA-Ames Research Center, Life Science Division, 94035, Moffett Field, Calif., USA aut European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/2(1992-03-01), 178-182 0301-5548 65:2<178 1992 65 421 https://doi.org/10.1007/BF00705077 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00705077 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Crenshaw Albert Department of Anatomy, University of Umeå, S-90187, Umeå, Sweden aut NATIONALLICENCE 700 1- Styf Jorma Department of Orthopaedics, East Hospital, University of Gothenburg, S-41685, Gothenburg, Sweden aut NATIONALLICENCE 700 1- Hargens Alan NASA-Ames Research Center, Life Science Division, 94035, Moffett Field, Calif., USA aut NATIONALLICENCE 773 0- European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/2(1992-03-01), 178-182 0301-5548 65:2<178 1992 65 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer