Abstract

The human foot is an adaptable work of living art. It gathers data from the ground and its surroundings and transports it through the spinal cord to the brain stem, the Limbic brain and the cerebrum for processing. It maintains support, stability and balance creating a foundation for posture. It receives instructions from the brain on how to pose its structure and be engineered by its motors, pulleys, screws, levers and wheels as a biomachine, thousands of times a day over one’s lifetime. Biomechanically, the foot has not been considered as engineered by biomachines that motorize and maintain support and balance of its forefoot, midfoot and rearfoot segments. These segments have independent structure and function but can also close pack to form a single pedal unit of various stiffness and functions allowing the foot to be a multi-function complex machine in closed chain. This paper introduces Supinatory End Range of Motion (SERM) and Pronatory End Range of Motion (PERM) of any joint of the foot and the interval motion that exists in between as the SERM-PERM Interval (S-P Interval) to replace kinetics and kinematics in biomechanics. SERM-PERM examination and the determination of the SERM-PERM Interval determine whether a joint segment will be close packed, flexible, injured or broken in both open and closed chain. This paper introduces The BioKickstand of The Foot as the most important biomachine of the foot and posture because it is the linchpin of human stance and motion. When working, the BioKickstand engages and disengages to morph from being a rigid lever to a functional adapter or anything in between thousands of times a day. S-P Interval motion is not pathological. When broken, the BioKickstand either has a low SERM-PERM Interval and the joint motion is reduced (hallux rigidus) and these BioKickstands are jammed. If the SERM-PERM Interval is high, the joint will not be able to engage for stability and balance (functional hallux limitus, bunions, postural complaints). The BioKickstand of the Foot must be diagnosed as working or broken and treated primarily in addition to any compensatory complaint or injury. this paper considers taking current mainstream lower extremity biomechanics to a neoteric place that may provide a path to improved structural and functional understanding and control of the foundation of human stance and movement, the masterpiece called the Human Foot.

Keywords: Spinal cord; BioKickstand; Rigid lever foot; Microtrauma; Pain; Weakness; Bones and joints

Abbreviations:

SERM: Supinatory End Range of Motion; PERM: Pronatory End Range of Motion; GRF: Ground Reaction Forces