Which of the following does not contribute to rateable disability?

The option that does not contribute to rateable disability is constant minimal. In the context of workers' compensation, rateable disability refers to a measurable level of impairment that affects an individual's ability to function in their usual capacity.

Constant minimal conditions typically imply a level of impairment that is either negligible or not significant enough to impact the worker's overall ability to perform their job duties. The other options, such as severe dislocation, moderate sprain, and readily observable impairment, are all conditions that have a more pronounced impact on an individual's physical capabilities and can be assessed for their effects on the worker’s performance and mobility, hence contributing to a determination of disability rating.

Understanding this distinction is important for evaluating the severity of injuries and their corresponding effects on a worker’s functionality, ultimately influencing how claims are handled within the framework of California Workers' Compensation laws.