Moment Arm Calculator

Visualize Leverage Changes During Range of Motion

1. Select Muscle (Insertion Dist.):

● Insertion Distance (r) cm

Joint Angle 90° 0° = Extended | 90° = Flexed

Calculated Moment Arm (d)

5.00 cm

Formula: d = r × sin(Angle)

Axis Bone Muscle Pull Moment Arm (d)

Biomechanical Insight: The ability of a muscle to produce torque depends heavily on the Moment Arm.
Even though the muscle attachment doesn't move, the leverage changes as the joint moves. Leverage is maximized at 90° because sine(90) = 1.