The standardised maximal step-up test (MST)-instructions to subject. First picture: after start position seen in the first picture, "go up as high as possible on the floor foot, stand still and find your balance". Second picture: "look forward and straighten your back while moving your body weight over to the step-up leg, stand still and again find your balance" as seen in the second picture. Third picture: "start the step-up by pressing the step-up foot into the board while extending in your knee, and during a slight bending forward slowly step-up onto the board". Fourth picture: end position with both feet on the board. After approved step-up test try a higher level, the highest approved level is the maximal step-up height for each leg.