- The purpose of this study was to determine normal values for torque of trunk flexion and trunk flexion with axial rotation. Eighty-two healthy subjects (39 men, 43 women) were tested for isometric torque of trunk flexion at four angles, and eccentric and concentric torque at 30 degrees/sec. All tests were performed in three positions of axial rotation: neutral rotation, trunk rotated 30 degrees to the right, and trunk rotated 30 degrees to the left. The results of two separate three-way analyses of variance (gender vs. position vs. angle/contraction) indicated that the torque of men was greater than that of women, eccentric torque was greater than concentric, and the torque in neutral rotation was greater than in right or left rotation. Isometric torque decreased with increased trunk flexion. Regression and correlation analyses demonstrated that gender was generally the best predictor of torque, and that all the torque measures were significantly correlated.