Biomechanics of the Jump Shot
Kelvin Wang
BIOL438
April 15, 2014
Technique—3 Phases
• Preparation—balance, center of mass over support
• Execution—jump and shoot, release
• Follow Through—landing, balance, center of mass
over support
Preparation
Execution
Source: The Seattle Times
Follow Through
Technique—Muscles Used
• Hip extension—hamstrings
(biceps femoris, semitendinosus,
semimembranosus), gluteus
maximus
▫ Fast-twitch  higher vmax, higher
power, more efficient at higher velocity
• Knee flexion/extension—
quadriceps muscle eccentrically
contracts in preparation, during
jump it concentrically contracts
▫ Slower-twitch  lower vmax, more
economical, recruit more motor units
▫ Gastrocnemius (fast-twitch) plays role
Source: www.oxford174.com
Technique—Muscles Used
• Shoulder upward rotation—
middle and lower trapezius
muscles, rhomboids, deltoids
• Elbow flexion/extension—
eccentric contraction of triceps,
then concentric to generate
force
Source: www.rci.rutgers.edu
▫ Fast-twitch fibers for greater power
• Wrist extension/flexion—add
spin, velocity to ball
▫ Fast-twitch fibers
Source: www.endoszkop.com
3 Shots
Source: www.lakernation.com
Source: ESPN
Source: wikiHow
LoggerPro Analysis
Normal Jump Shot—Momentum
• Before release, triceps extension (assume zero initial momentum):
▫
▫
▫
▫
a = ∆v/∆t = 51.39 m/s2 (from LoggerPro)
F = ma = (0.62 kg)(51.39 m/s2) = 31.86 N
∆t = 0.096 s, so:
J = F∆t = 3.06 kg-m/s
• At release:
▫ vx,ball = 4.40 m/s
▫ Total velocity = 7.18 m/s
vy,ball = 5.68 m/s
• Assume mball = 0.62 kg, then:
• p = mv = (0.62 kg)(7.18 m/s) = 4.45 kg-m/s
• Thus, the triceps extension motion for shooting the ball imparts 3.06 kg-m/s
impulse to the ball from preparation phase to release.
• Wrist flick motion gives ball extra velocity and could account for the
difference in impulsemomentum.
Normal Jump Shot—Work and Energy
• Kinetic energy = 0.5mv2
▫ At release: KE = 0.5(0.62 kg)(7.18 m/s) 2 =
15.99 J
• Work = ∆Energy = 15.99 J (assume E0 = 0)
• From the start of triceps extension to release:
▫ Power = Work/∆t = 15.99 J/0.096 s = 166.6 W
Pull-up Jump Shot—Momentum
• Before release, triceps extension (assume zero initial momentum):
▫
▫
▫
▫
a = ∆v/∆t = 139.9 m/s2 (from LoggerPro)
F = ma = (0.62 kg)(139.9 m/s2) = 86.74 N
∆t = 0.04 s, so:
J = F∆t = 3.47 kg-m/s
• At release:
▫ vx,ball = 4.70 m/s
▫ Total velocity = 7.81 m/s
vy,ball = 6.24 m/s
• Assume mball = 0.62 kg, then:
• p = mv = (0.62 kg)(7.81 m/s) = 4.84 kg-m/s
• Thus, the triceps extension motion for shooting the ball is quicker, and
imparts 3.47 kg-m/s impulse to the ball from preparation phase to release.
• Wrist flick motion gives ball extra velocity.
Pull-up Jump Shot—Work and Energy
• Kinetic energy = 0.5mv2
▫ At release: KE = 0.5(0.62 kg)(7.81 m/s) 2 =
18.91 J
• Work = ∆Energy = 18.91 J (assume E0 = 0)
• From the start of triceps extension to release:
▫ Power = Work/∆t = 18.91 J/0.04 s = 472.75 W
Fadeaway Jump Shot—Momentum
• Before release, triceps extension (assume zero initial momentum):
▫
▫
▫
▫
a = ∆v/∆t = 83.2 m/s2 (from LoggerPro)
F = ma = (0.62 kg)(83.2 m/s2) = 51.58 N
∆t = 0.08 s, so:
J = F∆t = 4.13 kg-m/s
• At release:
▫ vx,ball = 3.88 m/s
▫ Total velocity = 8.02 m/s
vy,ball = 7.02 m/s
• Assume mball = 0.62 kg, then:
• p = mv = (0.62 kg)(8.02 m/s) = 4.97 kg-m/s
• Thus, the impulse from triceps extension is similar to a normal jump
shot, and imparts 4.13 kg-m/s impulse (more than normal or pull-up)
to the ball from preparation phase to release.
Fadeaway Jump Shot—Work and Energy
• Kinetic energy = 0.5mv2
▫ At release: KE = 0.5(0.62 kg)(8.02 m/s) 2 =
19.94 J
• Work = ∆Energy = 19.94 J (assume E0 = 0)
• From the start of triceps extension to release:
▫ Power = Work/∆t = 19.94 J/0.08 s = 249.25 W
Normal
Pull-up
Fadeaway
Impulse
3.05 kg-m/s
3.46 kg-m/s
4.17 kg-m/s
Momentum
4.34 kg-m/s
4.85 kg-m/s
4.96 kg-m/s
Force
31.6 N
89.2 N
52.6 N
Energy
16.03 J
19.31 J
19.83 J
Power
159.6 W
471.8 W
273.4 W
• Fadeaway jump shot gives more impulse to shot from triceps
extension
▫ Higher proportion of momentum is from triceps, less from wrist
flick
Normal
Pull-up
Fadeaway
Impulse
3.05 kg-m/s
3.46 kg-m/s
4.17 kg-m/s
Momentum
4.34 kg-m/s
4.85 kg-m/s
4.96 kg-m/s
Force
31.6 N
89.2 N
52.6 N
Energy
16.03 J
19.31 J
19.83 J
Power
159.6 W
471.8 W
273.4 W
• Pull-up jump shot results in more force in shooting the ball
▫ Running start could have effect
Force
Force (N)
100
50
0
Normal
Pull-up
Fadeaway
Normal
Pull-up
Fadeaway
Impulse
3.05 kg-m/s
3.46 kg-m/s
4.17 kg-m/s
Momentum
4.34 kg-m/s
4.85 kg-m/s
4.96 kg-m/s
Force
31.6 N
89.2 N
52.6 N
Energy
16.03 J
19.31 J
19.83 J
Power
159.6 W
471.8 W
273.4 W
• Normal jump-shot results in least kinetic energy to the ball
▫ Pull-up: running start helps transfer momentumhigher velocity at
releasehigher kinetic energy
▫ Fadeaway: adjusting for defendershoot ball faster vertically
Kinetic Energy
Kinetic Energy (J)
25
12.5
0
Normal
Pull-up
Fadeaway
Normal
Pull-up
Fadeaway
Impulse
3.05 kg-m/s
3.46 kg-m/s
4.17 kg-m/s
Momentum
4.34 kg-m/s
4.85 kg-m/s
4.96 kg-m/s
Force
31.6 N
89.2 N
52.6 N
Energy
16.03 J
19.31 J
19.83 J
Power
159.6 W
471.8 W
273.4 W
• Pull-up jump shot results in most power
▫ greater energy (increase W) and shorter release time (decrease ∆t)
Power
Power (W)
500
250
0
Normal
Pull-up
Fadeaway
Conclusions
• Fadeaway jump shot: more triceps used, faster
twitch muscles to generate greater impulse
▫ Efficient and economical, but difficult to execute
• Pull-up jump shot: greater force and greater
power on shot, due to running start
▫ However, relies on running startsudden stop
and jump. Slower twitch muscles in leg are less
economical at higher contraction speedsfatigue
• Normal jump shot: least energy, force, and
power produced, but not as tiring
References
• Alexander, M. (1990). The application of biomechanics to basketball
skills. CAHPER Journal, 56(3), 4-10.
• Haefner, J. (2008). Proper Basketball Shooting Technique,
Fundamentals, and Form. Retrieved from
http://www.breakthroughbasketball.com/fundamentals/shootingtechnique.html
• Okazaki, V. H. A., & Rodacki, A. L. F. (2012). Increased distance of
shooting on basketball jump shot. Journal of Sports Science and
Medicine, 11, 231-237
• Valente, R. (2010). Movement Phase. Jump Shot. Retrieved from
http://valentejumpshot.blogspot.com/20 10/10/movementphase.html
• Quist, J., VanNostrand, Z., Burns, B. (2012). Science of the 3-Point
Shot. Biomechanics of a 3-Point Shot. Retrieved from
https://sites.google.com/site/biomechanicszjb/science-of-the-3