instability(redirected from patellofemoral instability)
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Related to patellofemoral instability: Jumper's knee
1. tendency to variable or unpredictable behaviour
2. Physics a fast growing disturbance or wave in a plasma
A condition of a control system in which excessive positive feedback causes persistent, unwanted oscillations in the output of the system.
A property of the steady state of a system such that certain disturbances or perturbations introduced into the steady state will increase in magnitude, the maximum perturbation amplitude always remaining larger than the initial amplitude.
In a structure, the sudden loss of stiffness that limits its load-carrying capability, and in some cases results in the structure’s failure.
ii. A tendency of a body to continue moving away from its original state when disturbed by an external force and to continue after that force has been withdrawn.
iii. The failure of structures, such as the buckling of plates and panels under compression, and the failure of struts under end loads.