Examination of a neural cross-over effect using resting mechanomyographic mean frequency from the vastus lateralis muscle in different resting positions following aerobic exercise

Purpose To evaluate the potential neural cross-over effect between the vastus lateralis muscles in different postural resting positions. Methods Subjects exercised on an upright cycle ergometer, using only their dominate leg, for 2 min at 30 % VO2 peak. Following this warm-up, subjects then cycled (still using only their dominant leg) for 30 min at 60 % VO2 peak. After the aerobic phase, subjects cooled down (again, using only their dominant leg) for 2 min at 30 % VO2 peak. Resting mechanomyography mean frequency was measured prior to and following aerobic exercise. Results There was an approximate 6.3 +/- 6.8 and a 10 +/- 5.1 % increase (upright sitting position with the subject's knee joint angle fixed at 180 ); an approximate 7 +/- 6.6 and a 16.1 +/- 6.5 % increase (upright sitting position with the subject's knee joint angle fixed at 90 ); an approximate 0.5 +/- 6.8 and 3.7 +/- 5.6 % increase (lying supine position with the subject's knee joint angle fixed at 180 ); and an approximately 2 +/- 8.3 and 2.5 +/- 8.6 % increase (lying supine position with the subject's knee joint angle fixed at 90 ) in normalized mechanomyography mean frequency after aerobic exercise for the dominant and non-dominate vastus lateralis muscles, respectfully. Conclusion There appears to be a statistically significant neural cross-over effect for the vastus lateralis muscle, during three of the four postural resting positions, with the non-dominant vastus lateralis muscle having a greater increase in mechanomyography mean frequency.