Biomechanics Basics
What is "center of mass" and give one example of how moving it helps in sports.
Center of mass is the point where the body is balanced. Moving it forward can help speed up, e.g., a sprinter leaning forward at the start.
Name three things to watch when checking a basketball free-throw.
Balance/stance, arm/leg position, follow-through.
What is a common mistake in a basketball jump shot and why does it make you miss?
Elbow flares out → ball doesn’t go straight → less accuracy.
How do you fix elbow flare in a basketball shot? Give a simple drill.
Cue: “Keep elbow under the ball.” Drill: Close-range shots focusing on elbow and short follow-through.
Name 2 tools to measure sports skills (one must use video).
Video camera/smartphone and stopwatch.
What’s the difference between linear and angular motion? Give one sport example for each.
Linear motion: straight or curved path (e.g., sprinting).
Angular motion: rotation around an axis (e.g., gymnast somersault).
What’s the difference between practice feedback (formative) and final test (summative) in sports? Give a volleyball example..
Formative: in-practice corrections (fix serve).
Summative: end-of-unit test (score 20 serves)
What can happen if a runner overstrides?
Slower steps, more braking force, higher risk of injury (like hamstring strain).
How do you help someone keep a neutral spine when lifting? Give cues and a drill.
Cues: “Chest up, pelvis neutral” and “brace core.” Drill: Romanian deadlift with PVC and mirror feedback.
How does frame-by-frame video help in a golf swing?
Shows exact timing of weight shift, hip rotation, and club position → find errors.
How are force, mass, and acceleration connected? What happens to acceleration if you increase force but keep mass the same?
Force = mass × acceleration. More force → more acceleration if mass doesn’t change
What’s the difference between checking technique (process) and checking results (product)? Give one measure for each in baseball pitching.
Process: arm motion, measured by video.
Product: speed or strike %, measured with radar or scoring.
What are two signs a tennis player is using bad shoulder technique when serving?
Shoulders rise too much, or the arm rotates too early → can hurt shoulder and reduce power.
How would you correct a tennis player’s footwork over 2 weeks?
Week 1: verbal cues + video demos.
Week 2: visual frame-by-frame review + shadow drills with resistance bands.
How can a force plate help measure jump performance? Name 1 metric.
Measures vertical ground reaction force; gives take-off velocity.
Name two joint movements in a soccer kick and explain how they help kick the ball.
Hip flexion (thigh moves forward) and knee extension (lower leg swings) → together they create the kick.
Make a 3-part rubric for rating a sprint start. What would a top score look like?
Criteria: Reaction (fast start), Drive (strong push), Transition (good posture). Top score = fast reaction, powerful push, smooth posture.
If a soccer player hits the ball with their toe instead of the instep, what happens and why might it happen?
Less control, unpredictable path, weaker power. Likely cause: bad approach or poor ankle control.
Give a practice change to help a soccer player pass more accurately under pressure.
Make targets smaller + add a defender or time limit → forces focus and faster decisions.
Compare wearable sensors vs. stopwatch for running technique. One advantage each.
Sensors: detailed 3D motion. Stopwatch: simple and cheap.
How does torque help a tennis serve? Name two ways to make torque bigger.
Torque = force × lever arm; more torque → faster rotation.
Ways to increase: stronger muscles, longer arm position, trunk rotation.
Make a 4-step checklist to watch a swimmer’s freestyle.
1. Head position neutral, 2. Arm recovery correct, 3. Breathing & kick timing, 4. Hand entry consistent.
A volleyball player can’t hit spikes hard. Name 3 possible technical mistakes.
1. Poor arm swing/shoulder rotation → less power,
2. Bad jump timing → less momentum
3. Weak legs → less force.
Plan 3 swim sessions to fix body alignment and kick timing. How do you measure progress?
Session 1: alignment drills with kickboard.
Session 2: timing drills with metronome.
Session 3: full swim sets with video feedback.
Measure: stroke count per 25m, drag reduction, kick timing vs. arm entry.
How can motion capture improve a throwing motion? Name 3 things to look at.
Measures joint angles, speeds, and segment timing. Look at: shoulder rotation, elbow speed, trunk rotation timing.