At the option of the Board, any employee injured at work may be directed to perform available lighter work which he/she is qualified to perform on a part-time or a full-time basis. The board may require an appropriate medical release as a condition precedent to the performance of light duty. Employees on light duty shall receive an hourly rate of pay determined by the Board, which amount shall not be less than fifty percent (50%) of their regular straight time hourly rate of pay.