This study was designed to determine if muscular innervation during imagery was specific to muscles needed for actual performance and if individuals of different skill levels utilizing two imagery perspectives demonstrated differing amounts of muscular activity. A final purpose was to assess the effectiveness of the meditation-relaxation approach used in karate training to reduce tonic activity in muscles. Beginning and advanced (N = 36) karate students were randomly assigned to counterbalanced conditions of imagery perspective (internal/external) x skill level (beginning/advanced) x side (right/left) in a factorial design. EMG data were collected from both deltoid muscles before and after a relaxation session, during and between performances of imaginary arm lifts and between imagery perspectives. Following testing, a questionnaire involving the subject's perception of success at imagery was completed. The results of this investigation suggest that skill level does influence muscle innervation during imagery and that this innervation appears specific to the muscle group necessary to execute the task. Internal imagery produces more EMG activity than external imagery. The meditation-relaxation techniques used in karate do significantly reduce tonic muscle activity.

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A full-scale airfield pavement test section was constructed and trafficked by the U.S. Army Engineer Research and Development Center (ERDC) to evaluate the performance of relatively thin airfield pavement structures. The test section consisted of 16 test items that included three asphalt pavement thicknesses and two different aggregate base courses. The test items were subjected to simulated aircraft traffic to evaluate their response and performance to realistic aircraft loads and to evaluate the effect of reductions in tire pressure on thin asphalt pavement. Rutting behavior, pavement cracking, instrumentation response, and falling weight deflectometer response were monitored at selected traffic intervals. The results of this study were used to extend existing Department of Defense pavement design and evaluation techniques to include the evaluation of airfield pavement sections that do not meet the current criteria for aggregate base quality and minimum asphalt concrete surface thickness. These performance data were used to develop new aggregate base failure design curves using existing stress-based design methodology.

Sixteen nonstandard asphalt pavement test items were subjected to accelerated traffic testing to determine whether reductions in aircraft tire inflation pressure had a meaningful effect on pavement performance. Materials evaluated included a strong and weak base course (limestone and gravel), three asphalt thicknesses (2.5 cm, 3.8 cm, and 6.3 cm), and two aircraft types (C-130 and C-17). Each single-wheel aircraft tire was operated at two tire inflation pressures, that is, normal operating pressure and approximately 20% below normal, while maintaining total wheel load. Rutting behavior and surface cracking were the primary measured distress mechanisms and were used to evaluate pavement performance. It was found that reducing tire inflation pressure on the weak base course materials had little effect on rutting performance, suggesting that total load rather than tire pressure dominated performance. Conversely, tire pressure reductions on strong base course materials provided an improvement in rutting performance ranging from 15% to 73%. Improvement in surface cracking was observed in some cases with a reduction in tire inflation pressure; however, a meaningful amount of surface cracking was not observed in most test items until near or after 25.4 mm of rutting. Thus, it can be concluded that the primary mode of failure was pavement rutting rather than extensive fatigue cracking. Overall, it was found that a reduction in tire pressure on competent aggregate base improved pavement performance, which could permit increased aircraft operations on thin flexible airfield pavements.