Answer for The Knee Pain -we would like to suggest you to use it when you are tired and need a rest, it feels like kind of message, you will feel comfortable and relax. Furthermore, not only for people working in office, We also believe that the ESL Under Desk Elliptical is great for leg exerciser for seniors. Electric Under Desk Elliptical are ideal for - 1.Desk-bound professionals who sit for long hours.2.Individuals with limited mobility, Including those recovering from injuries or surgeries.3.Students who are going to increase focus, alleviate stress, and stay active while studying.4.Health-conscious individuals who are aiming to increase daily activity, achieve weight loss or maintain their current weight. Auto & Manual Exercise Modes - This Compact Desk Elliptical features 2 modes: auto (P1-P3) and manual (5 speeds, H1-H5,1.5-5.7KM/h) to personalize your workout for leg training or rehab. Includes unique remote control and forward/backward pedal movement. Note: Use Only When Sitting.