Muscle contraction is the activation of tension-generating sites within muscle fibers.In physiology, muscle contraction does not mean muscle shortening because muscle tension can be produced without changes in muscle length such as holding a heavy book or a dumbbell at the same position.n contrast, a muscle contraction is isotonic if muscle length changes but the muscle tension remains the same. Furthermore, if the muscle length shortens, the contraction is concentric.
Senior Systems Administrators with one to two decades of relevant experience report an average salary of approximately $85K. After two decades in the workforce, the average Senior Systems Administrator generally earns more than ever; median pay for this group is estimated at $92K.
Salary Outlook. The Labor Department reports that database administrators made a median salary of $78,520 in 2013. The highest-paid 10 percent in the profession earned $120,990, while the lowest-paid earned $43,720 that year.he top-paying metropolitan areas for this position are located in San Francisco; Boulder, Colorado; and San Jose, California. Bringing home an average annual salary of $80,740, or about $38.82 per hour, database administrators are well-compensated.