The Lumbar Extension allows you to isolate and test the function of your lumbar extensor muscles through a full range of motion. Thanks to its patented fixation and pelvic stabilization, all auxiliary muscles that work synergistically are eliminated from the muscle function chain. Together with a thigh pad, a wide thigh strap ensures the maximum possible fixation of the pelvis while it is pressed against the pelvic roller via the footplate. A footplate is adjustable so that the knees are slightly higher than the hips. For therapy, the patient is fixed in the machine so that the roller does not rotate during the exercise. The lumbar extension uses a counterweight to balance the upper body mass of the user. The removal of gravity during the movement makes it possible for individual differences in body weight to be determined reliably and without error. Using an isometric force measurement of the lumbar extensor muscles ensures personal treatment planning for each user. Compared to dynamic force measurement, this type of force measurement is risk-free because it is conducted in standardized measurement positions within the range of motion of an individual patient. The fine gradation of the weight stack allows for gradation in increments of one pound, allowing you to select a weight between 10 and 400 pounds at any time. Due to the absence of weight guide rods, the weight guide works with low friction. A computer measures the lumbar extensor muscles’ active extension force (strength). The measurements are taken first in the maximum possible flexion position and then in the maximum possible extension. Through comparison with age, gender, and weight-specific norm data, the curve of strength relative to flexion/extension can be calculated. Based on this force measurement, the individual training resistance of the respective patient is determined. Resistance is variably adapted to the spine’s muscles during the movement’s execution via a torque disk according to the strength curve.