Welcome to Movement Analysis!

Ever wondered why a gymnast can spin so fast, or why it’s easier to lift a heavy weight in a certain way? That is what Movement Analysis is all about! We are going to look "under the hood" of the human body to see how our bones and muscles work like machines (levers) and how we move through space (planes and axes).

Don't worry if this seems a bit "physics-heavy" at first. We will break it down into simple steps with easy ways to remember everything you need for your Edexcel exam.


1. Lever Systems

In PE, we think of our bones and joints as a lever system. This system helps us move our body weight or sporting equipment (like a racket or a ball).

The Four Parts of a Lever

Every lever has four parts. To remember them, think of the word LFRE (like "Leafy" without the 'y'):

  • Lever (Bone): The hard bar that moves.
  • Fulcrum (Joint): The fixed point where the lever turns.
  • Resistance/Load (Weight): The weight that needs to be moved (can be a body part or a dumbbell).
  • Effort (Muscle): The force used to move the load (provided by muscles contracting).

The Three Classes of Levers

The "Class" of a lever depends on what is in the middle. Use the mnemonic FLE 123 to never forget this!

Mnemonic: FLE 123

  • Fulcrum in the middle = 1st Class Lever
  • Load in the middle = 2nd Class Lever
  • Effort in the middle = 3rd Class Lever
First Class Lever (F is in the middle)

Analogy: A seesaw or a pair of scissors.

Sporting Example: Moving your head to extend the neck (e.g., heading a football). The joint (Fulcrum) is in the middle, the weight of your head is the Load, and the neck muscles provide the Effort.

Second Class Lever (L is in the middle)

Analogy: A wheelbarrow.

Sporting Example: Standing on your tiptoes (plantar-flexion) at the ankle. The ball of your foot is the Fulcrum, the body weight is the Load (in the middle), and the calf muscle (gastrocnemius) provides the Effort.

Third Class Lever (E is in the middle)

Analogy: Using a pair of tweezers or a fishing rod.

Sporting Example: A bicep curl. The elbow is the Fulcrum, the muscle pulls in the middle (Effort), and the weight in your hand is the Load.

Did you know? Most levers in the human body are third-class levers! They are great for creating speed and a wide range of motion.


2. Mechanical Advantage and Disadvantage

Levers give us different "bonuses" depending on how they are set up. We measure this using Mechanical Advantage.

The formula for Mechanical Advantage is:
\( \text{Mechanical Advantage} = \frac{\text{Effort Arm}}{\text{Resistance (Load) Arm}} \)

Mechanical Advantage

This happens when the Effort Arm (distance from fulcrum to effort) is longer than the Load Arm (distance from fulcrum to load).

  • Which lever? Second-class levers (like your ankle).
  • The Bonus: You can move a very heavy load with relatively little effort.
  • The Trade-off: You can't move the load very fast or very far.

Mechanical Disadvantage

This happens when the Load Arm is longer than the Effort Arm.

  • Which lever? Third-class levers (like your elbow).
  • The Bonus: You get increased speed and a huge range of movement.
  • The Trade-off: You need a lot of effort to move even a small load.

Quick Review:
2nd Class = Power (Mechanical Advantage)
3rd Class = Speed (Mechanical Disadvantage)


3. Planes and Axes of Movement

To describe how an athlete moves, we use Planes (flat surfaces) and Axes (imaginary pins/lines) that the body rotates around.

Body Planes (The Surfaces)

Imagine a giant sheet of glass slicing through your body:

  • Sagittal Plane: Splits the body into Left and Right. Movements are forwards and backwards (e.g., running, cycling).
  • Frontal Plane: Splits the body into Front and Back. Movements are side-to-side (e.g., star jumps).
  • Transverse Plane: Splits the body into Top and Bottom. Movements involve rotation or twisting (e.g., a 360-degree spin).

Body Axes (The Rotation Lines)

Imagine a metal rod (an axis) going through your body that you rotate around:

  • Frontal Axis: Runs side-to-side (hip to hip). Like the rod in a table-football player.
  • Sagittal Axis: Runs front-to-back (belly button to spine).
  • Vertical Axis: Runs top-to-bottom (head to toes). Like a figure skater spinning.

4. Putting it Together: The "Pairs"

In the exam, you must know which Plane and Axis work together for specific sporting actions. This is often the trickiest part, so use this table as your "cheat sheet":

Sporting Action Plane Axis
Somersault (Front, Back, Tucked, or Piked) Sagittal Frontal
Cartwheel Frontal Sagittal
Full Twist Jump (Trampolining) Transverse Vertical

Common Mistakes to Avoid

  • Confusing Frontal Plane and Frontal Axis: Remember, the Frontal Plane is for side-to-side movement (like a cartwheel), but the Frontal Axis is the rod you rotate around during a somersault.
  • Mixing up 2nd and 3rd Class Levers: Always draw a quick sketch! If the calf is working, it's 2nd class (Load in middle). If the bicep or hamstring is working, it's 3rd class (Effort in middle).

Key Takeaway Summary:
1. Use FLE 123 for levers.
2. 2nd class = Power; 3rd class = Speed.
3. Somersault = Sagittal Plane / Frontal Axis.
4. Cartwheel = Frontal Plane / Sagittal Axis.
5. Twist = Transverse Plane / Vertical Axis.

You've got this! Practice drawing these movements and labeling the planes and axes, and they will become second nature in no time.