Movement and Rotation in Planes and Axes
Plane of movement
A plane of movement is an imaginary flat surface that divides the body into sections and along which movements occur.
- Movements occur within a plane and are controlled by the muscles, joints, and nervous system.
- Each plane allows specific types of movement, and understanding them is crucial for analyzing human motion in sports and exercise.
Anatomical Plane
An imaginary flat surface used to divide the body for anatomical study and movement analysis. The main anatomical planes are: Sagittal Plane, Frontal (Coronal) Plane and Transverse Plane
- Consider the body is moving between three sheets of glass, one slicing from front to back, another from side to side, and the third cutting horizontally.
- Each movement must follow the direction allowed by the glass.
The Three Anatomical Planes
- The human body moves in three anatomical planes: sagittal, frontal, and transverse.
- Each plane allows different types of movement.
1. Sagittal Plane
- The sagittal plane divides the body into left and right halves.
- Movements in this plane occur forward and backward and involve changes in joint angles.
In a squat:
- Knee flexion during descent
- Hip flexion as you lower
- Both knee and hip extension as you rise
- All movement occurs in the sagittal plane
Common Movements in the Sagittal Plane
- Flexion: Decreasing the angle between two bones (e.g., bending the knee in a squat).
- Extension: Increasing the angle between two bones (e.g., straightening the knee in a squat).
- Dorsiflexion: Lifting the toes towards the shin (e.g., during the back phase of a running stride).
- Plantarflexion: Pointing the toes downward (e.g., pushing off in a sprint start).
Examples in Sports:
- Running: The legs and arms move forward and backward in the sagittal plane.
- Cycling: The knees flex and extend during each pedal stroke.
- Weightlifting: Movements such as deadlifts, lunges, and squats occur primarily in this plane.
- Students often confuse flexion and extension.
- A simple rule: Flexion makes the joint angle smaller, extension makes it larger.
If a movement occurs in the sagittal plane, the axis of rotation is perpendicular to it, in this case, the frontal axis.
2. Frontal Plane
- The frontal plane divides the body into front (anterior) and back (posterior) halves.
- Movements in this plane occur side-to-side.
Common Movements in the Frontal Plane
- Abduction: Moving a body part away from the midline (e.g., raising the arms in a lateral raise).
- Adduction: Moving a body part toward the midline (e.g., bringing the arms back down in a lateral raise).
- Inversion: Turning the sole of the foot inward (e.g., rolling an ankle).
- Eversion: Turning the sole of the foot outward.
- Elevation: Raising a body part (e.g., shrugging the shoulders).
- Depression: Lowering a body part (e.g., dropping the shoulders).
Examples in Sports:
- Jumping Jacks: The arms and legs move in the frontal plane.
- Side Lunges: Movement occurs side-to-side.
- Defense in Basketball: Lateral shuffling is an example of movement in the frontal plane.
A good way to remember this plane is to consider standing between two glass walls, you can move side-to-side, but not forward or backward.
3. Transverse Plane
- The transverse plane divides the body into top (superior) and bottom (inferior) halves.
- Movements in this plane involve rotation.
Common Movements in the Transverse Plane
- Rotation: Twisting a body part around its axis (e.g., turning the head side to side).
- Pronation: Rotating the forearm so the palm faces downward.
- Supination: Rotating the forearm so the palm faces upward.
- Horizontal Flexion: Moving the arm across the body at shoulder level (e.g., chest fly).
- Horizontal Extension: Moving the arm away from the body at shoulder level.
- The transverse plane is like a tabletop slicing through your waist.
- Movements in this plane involve rotation, such as turning your head or twisting your torso.
Examples in Sports:
- Golf Swing: The torso rotates in the transverse plane.
- Baseball Pitch: The shoulders and torso rotate.
- Tennis Forehand: The hips, torso, and shoulders rotate in the transverse plane.
Students often confuse planes with axes. Remember: Movement occurs IN a plane but AROUND an axis. Like a door swings in a plane but rotates around its hinges (axis).
Axes of Rotation
Axis of rotation
An axis of rotation is an imaginary line around which movement occurs.
Each movement in a plane occurs around an axis that is perpendicular to that plane.
Analogy- Consider a hinge on a door.
- The door moves around the hinge, just like body parts move around an axis.
1. Sagittal Axis (Anteroposterior Axis)
- Runs front to back through the body.
- Perpendicular to the frontal plane.
- Movements around this axis include abduction and adduction.
- A cartwheel occurs around the sagittal axis.
- A side lunge moves around the sagittal axis.
- A jumping jack rotates around this axis.
Many students assume the sagittal axis is related to the sagittal plane, but it is actually perpendicular to the frontal plane and controls side-to-side movements.
2. Frontal Axis (Mediolateral Axis)
- Runs side to side through the body.
- Perpendicular to the sagittal plane.
- Movements around this axis include flexion and extension.
- A somersault occurs around the frontal axis.
- A bicep curl involves rotation around the frontal axis.
- A squat moves around the frontal axis.
Since this axis runs side to side, it is always related to forward and backward movement.
3. Longitudinal Axis (Vertical Axis)
- Runs top to bottom through the body.
- Perpendicular to the transverse plane.
- Movements around this axis involve rotation.
- A ballet pirouette occurs around the vertical axis.
- A discus throw rotates around the vertical axis.
- A golf swing moves around the vertical axis.
Think of supination as holding a bowl of soup with your palm up.
Common MistakeStudents sometimes confuse plane and axis. Always remember:
- Movement happens in a plane.
- Rotation happens around an axis.
Types of Movements and Their Planes
Types of Movements in the Sagittal Plane
1. Flexion
Flexion
A movement that decreases the angle between two bones at a joint.
- Typically moves a limb forward (except for the knee, which moves backward).
- Involves muscle contraction that brings bones closer together.
Common movements with flexion:
- Elbow Flexion: Bending the arm during a bicep curl.
- Knee Flexion: Bending the knee during a squat or leg curl exercise.
- Hip Flexion: Lifting the knee toward the chest (e.g., high knees in sprinting).
- Neck Flexion: Tucking the chin toward the chest.
- A gymnast performing a tuck jump – The knees flex to pull the legs up.
- A soccer player preparing to kick – The knee flexes before striking the ball.
- A sprinter starting from the blocks – The rear leg undergoes knee flexion before pushing off.
Flexion can be remembered as a movement that makes a joint "smaller" or more "closed" (reducing the angle between bones).
Common MistakeSome students think flexion always moves a limb forward, but at the knee joint, flexion moves the lower leg backward.
2. Extension
Extension
A movement that increases the angle between two bones at a joint.
- Typically moves a limb backward (except for the knee, which moves forward).
- Involves muscle contraction that lengthens the joint angle.
Common movements with Extension:
- Elbow Extension: Straightening the arm when pushing a door open.
- Knee Extension: Straightening the leg after a squat.
- Hip Extension: Pushing the thigh backward, such as in sprinting or deadlifts.
- Neck Extension: Lifting the chin upward.
- A weightlifter performing an overhead press – The elbows extend to push the bar up.
- A swimmer pushing off the wall – The knees extend as the legs drive backward.
- A runner sprinting – The rear leg undergoes hip extension as it pushes off the ground.
If flexion decreases a joint angle, extension does the opposite - it increases it!
Note- Extension does not only happen when moving a limb backward.
- It also occurs at the knee joint when extension moves the lower leg forward, not backward.
3. Dorsiflexion
Dorsiflexion
Movement of the foot that pulls the toes upward toward the shin, decreasing the angle between the foot and lower leg.
- Occurs at the ankle joint.
- Involves the anterior tibialis muscle pulling the toes up.
Common movements with Dorsiflexion:
- Walking: The foot dorsiflexes when stepping forward.
- Running: The foot dorsiflexes before the push-off phase.
- Jumping: The foot dorsiflexes in preparation for takeoff.
- A sprinter positioning their feet in the starting blocks.
- A basketball player landing from a jump, toes flexed upward.
Consider for a moment that you're standing on your heels with your toes lifted, this is dorsiflexion!
TipA useful way to remember:
- Dorsiflexion = toes pointing up (as if digging your heels into the ground).
- Plantarflexion = toes pointing down (as if pushing off the ground).
4. Plantarflexion
Plantarflexion
Movement of the foot that points the toes downward away from the shin, increasing the angle between the foot and lower leg.
- Occurs at the ankle joint.
- Involves contraction of the calf muscles (gastrocnemius and soleus).
- Standing on tiptoes in ballet.
- Pressing the gas pedal in a car.
- Jumping off the ground in sports.
Examples of Plantarflexion in sports:
- A basketball player pushing off the ground for a dunk.
- A swimmer pointing their toes during a streamlined glide.
- A soccer player striking a ball with the top of their foot.
To remember plantarflexion, think of “planting” your foot into the ground or pushing down like pressing a pedal.
Case studyTennis Serve Analysis:
- Preparation phase:
- Shoulder flexion (sagittal plane)
- Trunk rotation (transverse plane)
- Execution phase:
- Shoulder abduction (frontal plane)
- Internal rotation (transverse plane)
- Follow-through:
- Multiple plane movements
- Complex joint interactions
Circumduction
Circumduction
Circumduction is a circular movement of a limb that occurs when the distal end moves in a circular path while the proximal end remains relatively fixed.
- It is not a single movement but a combination of:
- Flexion
- Extension
- Abduction
- Adduction
- Occurs at multiaxial joints such as the shoulder (glenohumeral joint) and hip (coxal joint).
- The joint remains stationary, but the limb traces a circular path.
- The range of motion depends on joint mobility and muscle flexibility.
- Arm Circles in Swimming – The shoulder joint moves through a full range of motion in freestyle and backstroke strokes.
- Softball Windmill Pitch – The arm moves in a continuous circular motion during a pitch.
- Wrist Circles – When warming up, moving the wrist in circular movements involves circumduction.
- Gymnast Performing Ribbon Twirls – The hand moves in circular paths while twirling the ribbon.
- A cricketer bowling a ball.
- A tennis player serving with a large wind-up motion.
- A soccer player rotating their foot before kicking a ball.
Consider drawing a large circle in the air with your arm while keeping your shoulder stationary, this is circumduction!
Common MistakeSome students confuse circumduction with rotation.
- Circumduction = A circular movement using multiple joint actions.
- Rotation = Movement around a single axis without changing joint position (e.g., turning the head side to side).
Protraction and Retraction
Protraction
Protraction
Protraction is the movement of a body part forward along a horizontal plane.
- Protraction involves anterior movement (moving forward).
- It occurs mainly at the scapulae and mandible.
- It is associated with pushing movements.
- A boxer extending their arm forward in a punch.
- A swimmer pushing off the wall at the start of a race.
- A basketball player reaching for a rebound.
Movement Analysis in Basketball:
- Jump Shot:
- Knee flexion/extension (sagittal)
- Shoulder flexion (sagittal)
- Wrist flexion (sagittal)
- Crossover Dribble:
- Trunk rotation (transverse)
- Hip abduction/adduction (frontal)
- Rebounding:
- Multi-plane movement
- Complex coordination
Retraction
Retraction
Retraction is the movement of a body part backward along a horizontal plane.
- It involves posterior movement (moving backward).
- It is most commonly occurs at the scapula (shoulder blades) and jaw (mandible).
- It is essential for postural alignment and rowing movements.
- A rower pulling the oars back during a stroke.
- A gymnast holding a perfect posture with their shoulders retracted.
- A weightlifter performing a deadlift, keeping their shoulders pulled back.
Protraction pushes forward, while retraction pulls backward, just like moving a drawer in and out!
Opposition and Reposition
Opposition
Opposition
Opposition is the movement of the thumb toward the fingertips, allowing the hand to grasp, pinch, or manipulate objects.
- It is unique to the first carpometacarpal joint (thumb joint).
- It is essential for fine motor skills and human dexterity.
- It involves abduction, medial rotation, and flexion of the thumb.
- Basketball Dribbling – The player grips the ball using opposition.
- Rock Climbing – Climbing requires thumb opposition to hold small holds.
- Golf Grip – The thumb helps stabilize the club.
Reposition
Reposition
Reposition is the movement of the thumb back to its normal position after opposition.
This movement restores the open hand posture.
Example- Releasing a Pencil after writing.
- Opening the Hand after gripping a racket.
- Releasing a Ball after throwing it.
Opposition = thumb to fingertips, Reposition = thumb back to normal!
Self review- Which axis does a gymnast rotate around during a backflip?
- Identify one exercise that involves movement in each of the three planes.
- If a cyclist is straightening their knee while pushing down on a pedal, what movement is occurring?
- In which plane do all flexion and extension movements occur?
- Why is opposition considered an essential movement for humans?
- Which movement occurs when the shoulder blades are squeezed together?
- How does opposition differ from simple thumb flexion?
