Relationship between Step count, Arm shape, and NFSM

Natural Foot Steps per Minute (NFSM) is the number of steps per minute that you walk naturally without bending your elbow. It's a simple pendulum, like a wall clock or a Viking ride.

This number depends on the length from the center of your palm to your shoulder joint. A first-grade child with an average arm length of about 0.4 meters would have an NFSM of 95, while an adult with an arm length of about 0.55 meters would have an NFSM of about 81.

When the number of steps taken is greater than the NFSM, the elbow begins to bend as the arm moves forward, and the faster you walk, the more the elbow bends.

When you run, your elbows are typically bent at about 90 degrees or less, and the faster you run, the smaller the angle.

When walking slower than the NFSM, the elbow does not bend, but a rotational component is added to the linear motion of the hand. The slower you walk, the greater the rotational component.