2 walking sessions - see Garmin Connect. \n\nHad PT today - really encouraged to strengthen core. \n\nWalking - first workout walking intervals 3.2 x 2 min, 4.1-4.3 x 1 min. Engaged core. Leaned forward. Incline up to 15\% and declines to -3\%. No discomfort anywhere. Lasted about 30 min. \n\nWalking - last workout at 0\% incline entire workout. Interval. 3.7mph x 4 min, 4 x 2 min. After 2 intervals, right front thigh pinching, left lateral knee extremely painful when bringing leg forward. Decreased speed to 1.5 and took small steps, but knee very painful. Flexed left buttock and knee for no bend or lift when bringing leg forward and little pain. At end of workout increased incline to 4.5\% and knee pain went away. Had something to do with the flat surface. \n\nFor most the walk I really tried to remember to tighten my core, tighten and tuck buttocks, and keep hips stable. Worked on arm swing too.