Meaning of Biomechanics

The word biomechanics is built from the Ancient Greek bios, meaning life, and mechanike (mechanics) — so biomechanics is the study of the mechanical principles of living organisms, particularly their movement and structure. It studies the body's mechanical characteristics in order to understand how it moves.

The branches of mechanics biomechanics uses

Mechanics itself has two sub-fields:

• Statics — the study of systems in a constant state: either at rest (no motion) or moving with a constant velocity.
• Dynamics — the study of systems in motion in which acceleration is present. Dynamics is further divided into:
  • Kinematics — the study of motion with respect to time, displacement, velocity and speed, whether in a straight (linear) line or a rotary (angular) direction; and
  • Kinetics — the study of the forces associated with motion, both the forces that cause motion and the forces that result from it.

Statics and dynamics in a real sporting action

These are not just definitions to memorise — they describe two genuinely different coaching situations. A gymnast holding a handstand, or a wrestler holding a defensive stance, is in static equilibrium: the forces acting on the body are balanced, and the relevant biomechanics is about balance and the base of support (developed fully in the Principle of Balance, section 8.3.2). A sprinter accelerating out of the blocks, or a discus spinning through the throwing circle, is instead in dynamic motion, with acceleration present throughout — here biomechanics must separately track how the motion looks (kinematics) and what forces are causing it (kinetics), the subject of section 8.4.

Why the distinction matters to a coach

Confusing statics and dynamics leads to poor coaching advice. Telling a shot-putter to simply "hold a wider base" — a static-balance fix — will not solve a problem that is actually dynamic, such as poor force application during the acceleration phase of the put. Correctly diagnosing which branch of mechanics explains a technical fault is the first step towards correcting it, which is exactly why biomechanics studies movement under these separate headings rather than treating "movement" as one single, undivided idea.

Sports biomechanics …