Balance Blueprint Slides Module 01: Statics
Balance Blueprint
Decoding the physics of stability through Center of Mass and Base of Support.
Biomechanics Series
The "Unliftable" Chair
The Challenge:
Stand 2 foot-lengths away from a wall.
Lean over so your head touches the wall.
Pull a chair under you.
Try to stand up while holding the chair to your chest.
Why can some people do this easily while others (mostly men) find it impossible? It's all about the Center of Mass.
Center of Mass (COM)
Definition
The point where the mass of the body is evenly distributed in all directions.
Variable
In humans, COM moves based on body position. It's usually near the sacrum (lower back) when standing upright.
The Rule
To stay balanced, your COM must remain vertically above your Base of Support.
Base of Support (BOS)
The Base of Support is the area of the body in contact with the ground plus the space between those contact points.
Large BOS = High Stability
Small BOS = Low Stability
2 Feet
Wide Base
Tripod
Triangular Base
Hands Only
Narrow Base
One Foot
Minimal Base
Gymnastics Progressions
1. Tripod
Head and two hands form a triangle. Low COM, large BOS.
2. Headstand
Hips rise above the head. COM is higher, requiring core control.
3. Handstand
Weight on hands only. High COM, small BOS. Maximum instability.
The Safety Checklist
Neck alignment: Look at your hands, not the wall.
Core engagement: "Hollow body" position to stack joints.
Shoulder push: Active shoulders create a solid column.
Gravity Games Lab Report Document ID BIO-01-LAB
Gravity Games Lab Report
Scientist:
Squad:
Date:
Subject: Biomechanics / Statics
EXP 01
The Unliftable Chair Challenge
Test the center-of-gravity trick. Stand 2 foot-lengths from the wall, lean head-first against it, and try to lift a chair to your chest before standing up.
Hypothesis
"I believe I will [ be able / not be able ] to stand up because..."
Observation Data
Participant Result:
Pass
Fail
Torso Length (Approx):
Biomechanical Analysis: Why did the chair stay 'grounded' or lift?
EXP 02
Mapping the Base of Support
Phase A: Tripod
Draw the shape formed by your hands and head on the ground.
Draw Base Map Here
Stability Level (1-10): ____
COM Height: [ Low / Mid / High ]
Phase B: Headstand
Analyze the shift as your hips move over your shoulders.
Draw Force Vectors
Balance Difficulty: ____
COM Shift: [ Up / Forward / Back ]
Phase C: Handstand
Compare the BOS to the Tripod. Why is this harder?
Annotate Joints
BOS Change: [ Larger / Smaller ]
Corrective Action (Hands): ________
Scientific Conclusion
Using the terms Center of Mass , Base of Support , and Vertical Alignment , explain why a gymnast must "stack" their joints to maintain a handstand.
Technical Safety Advisory: All inversions must be performed with a designated spotter. Do not attempt handstand transitions without matting and instructor clearance.
Balance Master Facilitation Guide Balance Master Guide
Teacher Facilitation & Safety Protocols: Lesson 01
Phase 1: The Chair Challenge (10 mins)
The Trick: Have students stand 2 foot-lengths from a wall, lean head-first against it, and try to stand while lifting a chair.
The Why (Scientific explanation)
Women typically have a lower COM (pelvis area) while men have a higher COM (shoulders). When leaning against a wall, a man's COM often shifts outside his BOS (feet). To stand up, he must shift weight backward, which is blocked by the wall. Most women's COM stays over their feet, allowing them to stand.
Phase 2: Skill Building (30 mins)
Progression Cues / Focus Physics Connection Tripod "Hands and head make a pizza slice." Maximizing BOS area. Headstand "Hips over ears, squeeze the glutes." Raising COM while maintaining verticality. Handstand (Wall) "Push the floor away, look at your thumbs." Minimal BOS requires constant micro-adjustments.
Discussion & Debrief
The "What" Questions
Where did you feel the weight shift in your hands?
What happened when your legs moved away from the wall?
The "Why" Questions
Why is a tripod easier than a handstand? (Geometric BOS)
How does "tight core" affect the COM stability?
Safety Critical
Spotting: Spotters must stand at the side, supporting the hips/waist. Never catch the legs first.Neck Health: No weight should be directly on the crown of the head. Weight is distributed to the hands.Exit Strategy: Teach students how to "roll out" of a handstand before they attempt it without the wall.
Required Equipment
- 1x Landing Mat per pair
- Clear wall space
- 1x Sturdy chair (for hook)
- Lab Report Worksheets
Teacher Tip
"Encourage students to use their fingers like claws in the handstand. This increases the active base of support!"
Spin Science Slides Module 02: Dynamics
Spin Science
Mastering Rotational Mechanics: The physics of the Forward and Backward Roll.
The Great Hoop Race
Predict the Winner:
We have a LARGE HOOP and a TINY RING of equal mass. We race them down a ramp.
"The smaller the radius, the faster the rotation."
Physics Law: Conservation of Angular Momentum
LARGE RADIUS
Small Radius
The Rotation Secret
\[ L = I \omega \]
Momentum (L)
Inertia (I)
Velocity (\(\omega\))
If you want to spin FAST (\(\omega\)), you must make your moment of inertia (\(I\)) SMALL by tucking in your body!
The Biomechanical Tuck
01
Chin to Chest
Protects the cervical spine and initiates the "tuck" shape.
02
Knees to Nose
Reduces the radius of rotation to the absolute minimum.
03
The Push
Translating linear momentum into angular momentum.
Stay Small, Move Fast
If you un-tuck mid-roll, your inertia increases and you will lose rotational speed, getting stuck on your back.
Mechanical Failures
The "Flat Back"
When the spine stays straight, the surface area hitting the mat is too large.
RESULT: High friction + No momentum = Stuck
The "Leading Head"
Looking forward or diving head-first.
SAFETY RISK: High Impact on C-Spine
Tuck and Roll Tracker Tuck and Roll Tracker
Observation & Data Analysis: Rotational Dynamics
Document BIO-02-TRACK
Analyst Name
Tumbling Subject
Session Date
1
Radius of Rotation Comparison
Perform or observe two variations of a forward roll. Rate the angular velocity (speed of spin) for each.
Variation
Spin Speed (1-10)
"Open" Roll (Loose Tuck)
"Tight" Roll (Chin to Chest)
Physics Synthesis
Using the "Hoop Race" analogy, explain why the "Tight" roll required less effort to complete.
2
Biomechanical Checklist
Skill: Forward Roll
Chin fully tucked to sternum?
Y N
Heels brought close to glutes?
Y N
Stands up without hand use?
Y N
Correction Strategy:
Skill: Backward Roll
"Pizza Hands" placement?
Y N
Consistent radius (stayed tucked)?
Y N
Adequate push from arms?
Y N
Correction Strategy:
Core Physics Note
Conservation of Angular Momentum
L = Iω
Rolling Mechanics Teacher Notes Rolling Mechanics Notes
Instructional Strategies & Common Pitfalls: Lesson 02
Phase 1: The Demonstration (5 mins)
Materials: A large hula hoop and a small weighted ring (or a small hoop).
The Key Question
"If they weigh the same, why does the small one spin faster?"
Answer: The mass is closer to the center (smaller radius of rotation), reducing the Moment of Inertia . A lower moment of inertia allows for higher angular velocity.
Phase 2: Skill Progression
The Forward Roll
The Setup: Squat position, hands flat on mat, shoulder-width.The Initiation: Hips lift high, chin tucks to sternum.The Contact: Back of the neck/shoulders touch the mat (NEVER the crown of the head).The Finish: Reach forward with hands to stand up without using them for balance.
The Backward Roll
The Setup: Squat with "Pizza Hands" (palms up next to ears).The Initiation: Sit back low, rounding the spine immediately.The Push: As hands hit the mat, push hard to clear the head.Common Error: Turning the head to the side (safety risk). Ensure chin stays central.
Spotting Cues
Forward Roll
"Hand on back of the thigh, other hand on the back of the neck/shoulders to guide the tuck."
Backward Roll
"Support the hips as they rotate over. Lift the hips slightly to take pressure off the neck."
Red Flags
- Crown of head hitting mat
- Elbows flaring wide
- Untucking mid-roll (flat back)
- Legs crossing or flailing
Differentiation
For students struggling with the backward roll, use an inclined mat (cheese wedge) to allow gravity to assist the rotation.
Momentum Manifolds Slides Module 03: Momentum
Momentum Manifolds
The Geometry and Leverage of the Cartwheel.
The Geometry of Movement
Hand-Hand-Foot-Foot
A perfect cartwheel isn't just a flip—it's a linear weight transfer across a 2D plane.
THE SEQUENCE:
Dominant Foot (Lead)
Hand 1
Hand 2 (Rotated 90°)
Trailing Foot
Foot 1
Hand 1
Hand 2
Foot 2
LEVERAGE: THE LONG LEG
Torque (\(\tau\))
Torque is force applied at a distance from a pivot.
\[ \tau = r \times F \]
The Leg as a Lever
The longer the lever (straight leg) and the faster the swing (force), the more momentum you generate to reach a vertical position.
The Goal
Convert HORIZONTAL running momentum into ANGULAR momentum to carry you through the inversion.
The Frontal Plane
Common cartwheel mistake: "Belly to the floor."
The Plane Break
If your hips twist early, you exit the frontal plane. This creates unstable landing forces and reduces efficiency.
Maintain Alignment
BUILDING THE CARTWHEEL
1. Bunny Hops
Hands on a line, jumping feet from side to side. Focus on the lateral weight transfer.
2. Scissor Kicks
Higher hips, kicking one leg up at a time. Using the leg as a lever for the first time.
3. Full Cartwheel
Total verticality. Hips, shoulders, and hands all in one line on the tape.
Cartwheel Geometry Guide Geometric Audit CAR-03-GEO
Cartwheel Geometry Guide
Athlete:
Coach:
SESSION OBJECTIVE: MINIMIZE DEVIATION FROM THE FRONTAL PLANE
Step 1
Hand & Foot Sequencing
In the boxes below, label the order (1, 2, 3, 4) of contact for a Left-Lead cartwheel. Then, draw arrows representing the Direction of Force for each contact point.
Lead Foot
Hand 1
Hand 2
Rear Foot
Step 2
Torque and Lever Efficiency
Lever Comparison
Compare a cartwheel performed with Bent Knees vs. Straight Legs. Explain why straight legs generate more torque using the lever formula.
Momentum Conversion
How does the "Lunge" (the first step) create the force necessary for the inversion?
Frontal Plane Audit
Did the athlete's body stay "flat" against the imaginary wall?
Shoulders square to line?
Hips untwisted in air?
Landing on the line?
Correction Drill Needed:
Biomechanics Principle
Torque and Angular Acceleration
τ = rF sin(θ)
Cartwheel Coaching Cards Cartwheel Coaching Cards
Technical Cues & Mechanical Corrections: Lesson 03
Phase 1: Entry
The Power Lunge
Scientific Purpose: Generating linear momentum and lowering the COM to prepare for leverage.
Cues:
"Reach for the horizon before reaching for the floor."
"Big step, deep bend in the front knee."
Phase 2: Contact
The T-Placement
Scientific Purpose: Aligning the pivot points to maintain movement in the frontal plane.
Cues:
"Turn the second hand like a screwdriver."
"Look at the first hand as the second one lands."
Phase 3: Inversion
The Scissor Kick
Scientific Purpose: Using the leg as a long lever to maximize torque and angular acceleration.
Cues:
"Kick the ceiling with your back heel."
"Lock the knees to make your legs 'heavier' for the swing."
Phase 4: Exit
The Snap-Down
Scientific Purpose: Decelerating angular momentum and returning the COM to a stable upright BOS.
Cues:
"Pull your chest up as the feet hit."
"Finish in a lunge, looking back at the line."
Troubleshooting Mechanics
OBSERVATION MECHANICAL CAUSE DRILL / FIX "Belly-to-Floor" Early hip rotation; loss of frontal plane. Cartwheel against a wall. "Short Leg" Landing Insufficient torque; knees bent. Scissor kicks over a block. Veering off the line Hand alignment is zig-zagged. Tape lines for specific hand spots.
Impact Insight Slides Module 04: Impact
Impact Insight
Force Absorption, Landing Mechanics, and the Physics of Safety.
The Egg Drop Rule
How do you drop an egg from 10 feet without breaking it? Increase the time of impact.
Impulse Strategy:
"In gymnastics, YOUR JOINTS are the egg. The way you land determines if they break."
EGG
Time + Surface Area = Survival
The Impulse Theorem
\[ F \Delta t = m \Delta v \]
Force (F)
Time (t)
Mass (m)
Change in Velocity (v)
To reduce the FORCE on your ankles and knees, you must increase the TIME it takes to come to a stop.
Methods of Dissipation
1. The "Stuck" Landing
Absorb force by bending ankles, knees, and hips (Triple Flexion).
Time of impact: ~0.2 seconds.
Best for low-momentum skills.
2. The "Safety Roll"
Transfer vertical force into Rotational Momentum.
Time of impact: ~1.5 seconds.
Best for high-momentum skills or "over-rotating".
WHY WE USE MATS
Mats are designed to compress. This compression isn't just "softness"—it's a mechanical tool.
Mechanical Benefit:
"The mat adds 2-3 inches of 'travel' distance, which increases the time of deceleration, effectively cutting the peak force on your joints by up to 80%."
Hard Floor
HIGH PEAK FORCE
Time: 0.01s
Gymnastics Mat
LOW PEAK FORCE
Time: 0.15s
Landing Logic Lab Report Stress Test Unit IMP-04-LAB
Landing Logic Lab
Athlete:
Date:
Hypothesis: Increasing the duration of deceleration (\(\Delta t\)) will result in lower peak force (\(F\)) experienced by the skeletal structure.
EXP 04.1
The Impulse Curve
In the graph area, sketch two curves representing the force of a landing:
A: "Stiff-Legged" Landing
B: "Triple Flexion" Landing
Remember: The area under both curves (total impulse) is the same, but the peak is different.
Force (F) Time (t)
EXP 04.2
Triple Flexion Analysis
Joint Correct Flexion Action Mechanical Result Ankles Dorsiflexion (heels to mat) Initial dampening of vertical velocity. Knees Hips
Scenario: The Over-Rotation
You perform a cartwheel with too much momentum and are "falling" forward. Why is a Safety Roll better than trying to "Stick" it?
Mechanical Injury Risk
Define "Point Loading" and explain how straight-leg landings contribute to stress fractures.
Deceleration Lab
Absorb. Dissipate. Survive.
\(\Delta p = J\)
Safe Landing Rubric Safe Landing Rubric
Assessment Standards for Impact Dissipation: Lesson 04
Performance Standards
Criteria Novice (1) Proficient (3) Mastery (5) Triple Flexion Landing is "heavy" or "stiff". Little to no bend in knees/ankles. Visible bend in ankles, knees, and hips. Feet stay flat. Dynamic absorption. Seamless transition from impact to stable squat. Acoustic Audit Loud "slap" or "thud" sound upon contact. Moderate sound; controlled foot placement. Silent or "soft" landing. Sound is dissipated across time. Stability (The Stick) Requires extra steps to balance. COM wobbles significantly. Minor balance check. Feet stay in contact with mat. Instant stability. COM is perfectly centered over BOS.
Emergency Protocol: The Safety Roll
Use this rubric for skills where horizontal momentum is too high to "stick" safely.
Initiation
Fingertips reach for mat immediately upon feet contact to guide momentum.
Curvature
Spine rounds into a "C" shape. No flat-back contact observed.
Recovery
Athlete returns to standing position in one continuous motion.
Observation Cues
"Look for the heels" (Do they touch?)
"Listen for the thud" (Is it loud?)
"Check the chest" (Is it upright?)
Immediate Disqualification
- Straight-leg landing (Locked knees)
- Head-first contact
- Landing outside the designated safety zone
Frame by Frame Slides Module 05: Analysis
Frame By Frame
Using Video Analysis to Bridge Physics and Performance.
The Eye of the Lens
The human eye sees at roughly 30-60 frames per second. A gymnastics skill happens in less than 2 seconds.
The Problem:
"We cannot see internal biomechanical errors at full speed. We need to freeze time to see the physics."
Analysis Checkpoints
01 / RADIUS
Roll Tightness
Freeze the roll at the peak. Draw a circle around the body. Is the mass as close to the center as possible?
02 / PLANE
Cartwheel Line
Use the drawing tool to trace the path of the hips. Do they stay on the tape line, or do they "wobble" left/right?
03 / TIME
Landing Time
Count the frames from "Initial Contact" to "Full Stop". More frames = Lower Force.
The Feedback Loop
A
Record
Stable camera, side-view profile. Capture the whole skill + 1 second before/after.
B
Analyze
Scrub the video slowly. Identify the exact frame where alignment breaks.
C
Prescribe
Suggest one drill based on the physics (e.g., "Straighten legs to increase torque").
Tech is the Coach
The camera doesn't lie. Use it to prove your progress.
FINAL SUMMATIVE GOALS
Visual Proof
You must produce one annotated screenshot showing a biomechanical principle in action (COM, BOS, or Torque).
The "Why"
"Don't just show me the skill. Explain the physics that made it successful."
Biomechanics Audit Sheet Analysis Protocol BIO-05-AUDIT
Biomechanics Audit Sheet
Scientist:
Subject:
Instructions: Use video scrubbing to analyze the subject's movement. Focus on the mathematical markers discussed in the slides.
1
The Frame-by-Frame Breakdown
Skill Evaluated Key Physics Marker Observations (Scrubbing Results) Forward / Back Roll Radius of Rotation (I) Note frame where tuck is tightest vs loosest... Cartwheel Frontal Plane Alignment Do the hips deviate from the line? If so, at what hand contact? Landing (Any Skill) Time of Deceleration (\(\Delta t\)) Count frames from heel contact to full stop...
Correction Prescription
Based on the video evidence, what is the #1 mechanical fix this athlete needs?
WHY? (Connect to a physics law: Inertia, Momentum, or Impulse)
Annotated Capture
Attach/Sketch the most critical frame here. Draw the Center of Mass (COM) dot and the Base of Support (BOS) line.
Draw Physics Diagram Here
Analysis Tech Guide Teacher Notes Analysis Tech Guide
Teacher Logistics & Analysis Setup: Lesson 05
Phase 1: The Setup (10 mins)
App Recommendations:
Dartfish / Hudl Technique / OnForm: These apps allow for drawing lines and measuring angles directly on the video.Built-in Slow Mo: If apps aren't available, standard iPhone/Android slow-mo works but requires manual frame counting.
Phase 2: Peer-Review Flow
STEP 01
The Capture
Assign students into Triads : 1 Athlete, 1 Camera Operator, 1 Spotter. Rotate every 3 attempts. Ensure the camera is perpendicular to the mat for a true profile view.
STEP 02
The Scrub
Students must find the "Peak Rotation" in the roll and the "Vertical Peak" in the cartwheel. Draw the Center of Mass dot to see if it is vertically over the Base of Support.
Synthesis Prompts
"Did the video reveal an error you couldn't feel while doing the skill?"
"How does your 'ideal model' screenshot compare to your actual performance?"
Device Protocol
Educational Use Only: No social media posting or sharing of peer videos. All videos deleted at session end.Stable Tech: Use tripods or blocks if available. A shaky camera makes frame-counting impossible.
Teacher Spotlight
"Focus students on ONE metric at a time. If they try to analyze everything, they'll miss the physics. Start with just Radius of Rotation."
EQUIPMENT
- 1x Tablet/Device per group
- Drawing/Analysis App
- Charging Station
- Audit Worksheets
