You’ve heard me preach about form. It’s important. It’s the only thing that keeps you from injury. Age, fitness level, bone density, etc, are all important can all be made to betray you and result you in being out of commission for weeks, months, years or forever. Is it really worth it when you put it into perspective? Of course not. So let me say this once more … form is everything.

Understanding form does not mean memorizing moves. It does not mean blindly accepting what a trainer demonstrates or what you see on the internet. Understanding form means educating yourself on why good form works and additionally, understanding your own unique body and how to apply proper form to your own training.


There are three classes of levers.

First Class Lever

  • axis is placed between force and resistance
  • examples: crowbar, seesaw, scissors
  • examples in body:
    • elbow extension
    • triceps applying force to olecranon (F) in extending the non-supported forearm (R) at the elbow (A)
  • flexing muscle
    • agonist (F) and antagonist (R) muscle groups are simultaneously contracting on either side of a joint axis (A).
  • lever characteristics
    • balanced movement
      • axis is midway between force and resistance
      • e.g.: seesaw
    • speed and range of motion
      • axis is close to force
      • e.g.: elbow extension
    • force
      • axis is close to resistance


Second Class Lever

  • resistance is between axis and force
  • classic examples: wheelbarrow, nutcracker
  • complex example: rowing
    • paddle in water acts as slipping axis (A)
    • boat resistance is resistive force (R)
    • rower is motive force (F)
  • relatively few examples in body
    • planter flexion of foot to raise body up on toes
      • ball of foot (A) serves fulcrum as ankle plantar flexors apply force to calcaneus (F) to lift resistance of body at tibial articulation (R) with foot.
    • entire body during push-up
      • foot is axis of rotation (A) when reaction force of ground pushing against hands (F) lifts weight of body’s center of gravity (R).
  • lever characteristics
    • produces force: large resistance can be moved by a relatively small force
    • weight machines: more resistance needed, lower inertia, smoother feel.


Third Class Lever

  • force is placed between the axis and resistance
  • examples:
    • tongs: food (R) is supported by grip on handles (F) while axis is on opposite end.
    • shovelling: dirt on shovel (R) is lifted by force to handle by hand (F) while upper hand on end of shovel handle serves as axis (A)
    • rowing: oar is moved through water (R) by pulling on middle of oar (F) while holding end of oar with opposite hand (A).
      • Note: shovelling and rowing actions can also be first class lever systems if the hand closes to the force remains stationary (A) and the hand on the far end of the shovel or oar is moved (F).
    • batting: ball is hit (R) by moving bat toward ball with hand of far arm (F) while supporting lower portion of bat with hand of near arm (A).
    • example in body
      • most levers in body are third class
      • elbow flexion
        • Biceps and brachialis pull ulna (F) lifting the forearm, hand, and any load (R) at the elbow (A).
      • knee flexion
        • hamstring contracts (F) to flex the lower leg (R) at the knee (A).
    • lever characteristics
      • produces speed and range of motion
      • requires relatively great force to move even small resistances
      • weight machines: less resistance required, greater inertia
        • harder to start and stop movement


Still with me? If you can learn what is stated above you’ve essentially just learned how every single part of your body works. That’s part one of understanding form.


Simple Planes

The other essential aspect to understanding good form is to know how the body wants to move, was designed to move. It’s not just about using body levers incorrectly or with too much resistance as to cause tear and injury. The most common cause of physical injury is when a lever can no longer sustain the weight being put to it and attempts to enlist the help of other supporting muscles, which is natural, but because most of us never train in a “natural” way, those muscles are weak, under-developed, and often result in our body crossing planes it was never meant to, which can result in severe injury.


Simple exercises that cross a single body plane are essential and often what most trainers will start new clients with. It introduces good form early on. Sadly they don’t try to impart an education in the process which infuriates me to no end, but I refuse to rant about the fitness industry here and will stay focused on basic education.

A simple exercise example here is touching your toes from a standing position. You are employing the frontal/lateral plane, nice and simple. Can you think of any other examples?

Intermediate Planes

Once you are familiar with crossing a singular plane, the next stage in your physical education is to cross two planes at the same time. An example would be standing cross toe touches. Stand with your arms up, legs slightly apart. Bend at the waist, letting your fingers touch your opposite toes. This employs the frontal plane and the sagittal plane.

Advanced Planes

Herein lies the most common gym scenario. Stupid guy lifting stupid heavy weights with stupid form. He never read this post sadly. He thinks he’s cool. He thinks he’s awesome. Eventually when he snaps, and he will, I won’t be going over to see if he’s ok no matter how much he screams. In fact, you might not even hear him scream over the sounds of my laughter.


As you can see, the body planes are further broken down for distinction purposes.


Always train smart. Educate yourself. There is no excuse for injury. Learn the body levers and body planes. Think about what you are doing. Feel your body as you do the exercises. Listen to it as it tells you what feels right, what feels wrong and what feels like you are going to cause it to snap.

If you have any questions, please ask in the comments below. Dont’ be shy. I guarantee you there is someone else with the same question on their mind and if somebody doesn’t ask, then none of us will know and the education stops.

As always, fly strong.

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