1. The Biomechanics of a Free Throw Shot
BY: VINAY RAO
BIOL438
Professor rome
21 April 2011

2. Free Throw Basics
Definition – unopposed attempts to score points from a restricted area on the court (foul line), and are generally awarded after a foul on the shooter by the opposing team.
Four Basic Steps
Knee Bed
Ball Elevation
Ball Release
Wrist Pronation
Shooting Mechanics: BEEF
Balance
Elbow
Elevation
Follow Through

3. Free Throw: Muscles Recruited
Triceps
Triceps brachii muscle: long head, lateral head, and medial head
Work to extend the arm at the elbow
Biceps
Double-headed muscle located on the front of the upper arm.
Flexes the arm at the elbow
Deltoids
Responsible for arm abduction, movement observed in non-shooting arm, mainly utilized when pushing ball away from the body

4. Muscles Recruited Cont.
Pecs
Fan-shaped muscles covered that covers the upper portion of the chest and overlays the thin pectoralis minor.
Prime mover of arm flexion and assist the anterior deltoid in ball push
Wrist Flexors
Includes the flexor digitorum superficials and flexor digitorum profundus.
Act to flex the wrist and fingers – very important in follow through
Quadriceps
Allows “soft knees” through contraction of the quadricep muscles.
Calves
Comprised of gastrocnemeus and the soleus muscles – work to flex the foot.
Provides necessary motion for Kinetic Chain

5. Review of Literature
Subjective assessments of the product elements of angle and velocity of projection are abudent
Numerous understandings: some say high angle, some say low, some say 45 degrees particularly
Stability often cited as a factor of free throw accuracy
Release point: high or low release point?

6. Question
Subject: To test what biomechanical factors play a role in the success of a free throw shot
Hypothesis: Certain variables matter over others: i.e. velocity of ball upon release negligible, whereas balance and ball release are necessary.

7. Experimental Protocol
Subjects – Two skill levels will be observed, one of high skill and one of low skill.
Variables
Accuracy – confirmed skill level based on 20 free throw test
Height of Release Ratio – height of the ball upon release divided by height of the subject
Center of Gravity Ratio – distance from frontal aspect to center of gravity divided by base support length
Trunk Inclination – degrees of leaning either forward or backward
Velocity of Project – based on loggerpro analysis

8. The Competitors Kathlyn Herrick (low skill) Zack Rosen (high skill)
Credentials:
Math Major
Penn Relays 3 year participant…?
Zack Rosen (high skill)
Credentials:
Guard on Penn Varsity Basketball Team
415 Career Assists (4th all time at Penn), 1,121 points (28th all time at Penn)
First Team All Ivy (unanimous)

9. Kathlyn Herrick: Slow Motion Shot

10. Zack Rosen: Slow Motion Shot

11. Results Kathlyn Herrick Zack Rosen Free Throw Percentage 25% %70
Height of Release Ratio
1.077
1.269
Center of Gravity
0.613
0.4
Trunk Inclination
7 degrees
2 degrees
Resultant Velocity
7.65 meters per seconds
7.96 meters per seconds

12. Discussion
Accuracy: significant difference in free throw percentage illustrates varying skill level
Height Release Ratio: observed significant difference between release ratios – Rosen’s ball release was ~18% larger than Herrick’s.
Center of Gravity Ratio: the lower value of Rosen signified more stability whereas the higher value of Herrick’s (quite great) contributes may contribute to inaccuracy
Trunk Inclination: seemed to be negligible
Velocity of Projection: revealed to be not significant

13. Conclusions Higher Heights of Release is related to Higher Skill Level
Greater Stability is related to Higher Skill Level
Velocity Projection is not related to Skill Level

14. Supplemental Measurements
KE of the basketball:
Low Skill KE = 1/2mv2 = (1/2)(.624 kg)(7.65 m/s)^2 = J
High Skill KE = 1/2mv2 = (1/2)(.624 kg)(7.96 m/s)^2 = J
Momentum of the basketball:
Low Skill p = mv = (.624 kg)(7.65 m/s) = 4.77 kg*m/s
High Skill p = mv = (.624 kg)(7.96 m/s) = 4.96 kg*m/s
Similarity of KE and Momentum calculations highlight the potential irrelevance that velocity of basketball release has on free throw shot effectiveness

15. Further Directions
Increase the number of N to further prove statistically the importance of this data analysis
Perhaps test angle projection to see whether, like velocity, is somewhat independent on skill

16. References
Hudson, Jackie. A Biomechanical Analysis by Skill Level of Free Throw Shooting in Basketball. Biomechanics of Sports. 1982;