Enhancing the Tolerance of +GZ Acceleration by Optimizing the Use of Isometric Contractions in Combination with Straining Maneuvers.
Final technical rept. Oct 86-Sep 87,
EAST TENNESSEE STATE UNIV JOHNSON CITY DEPT OF PHYSIOLOGY
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Experiments were performed on 9 male subjects who exerted L-1 straining maneuver in a pilot chair apparatus with a seatback at 30 degrees and a spine-to-thigh angle of 110 degrees. The L-1 maneuvers were performed with or without simultaneous application of isometric contractions. Contractions were exerted at high levels of force in either a sustained fashion or in an intermittent fashion, in 15 sec periods, until fatigue occurred. Isometric contractions were exerted by either the forearm flexors handgrip, quadriceps, or jaw muscles at tensions of 70 MVC handgrip, quadriceps or 100 MVC jaw. During the experiments, changes in arterial pressure, heart rate and electromyographic activity, from the intercostals and the contracting muscle group, were recorded.
- Medicine and Medical Research