QUANTIFYING LOSSES IN KNEE EXTENSOR TORQUE DUE TO BED REST WITH THREE DIMENSIONAL TOPOGRAPHY 991

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Three sedentary volunteers underwent two weeks of simulated space flight(6* head-down bed rest) to examine its effect on quadriceps strength. Pre- and post-bed rest dynamic maximal strength tests evaluated quadriceps torque at seven angular velocities (30, 65, 100, 135, 170, 205, and 240*/s) using a LIDO isokinetic dynamometer. Three dynamic knee extension repetitions at each velocity were collected through full flexion(93*) and extension (8*). Repetitions producing the highest torque at each velocity were analyzed. Torque was analyzed in three dimensions(time, velocity, and angle) using a repeated measures ANOVA and illustrated using three-dimensional topography. Effects for time, velocity, and angle were noted (p<.05). Post hoc analysis employed dependent t tests. Significant pre-post torque decrements were observed at the following velocities and angles: 30*/s 75-69*, 65*/s 89-86*, 100*/s 90*, 170*/s 11-10*, and 205*/s 12-10*. These data provide an indication of knee extensor torque losses associated with two weeks of simulated space flight. Results also suggest velocities and angles where a resistance exercise countermeasure may be appropriate for this model.