the power clean - cpb-us-w2.wpmucdn.com€¦ · o fiber recruitment o fast-twitch fibers ....
TRANSCRIPT
The Power Clean Project by: Kamil Okroj
What is it?
O Explosive,
Olympic-style lift
O Emphasizes power
over strength
O Used a lot in football
training
O Video
Muscles Used
O The “Posterior Chain”
O Lower Back, Glutes,
Hamstrings, Calves
O Upper Back
O Traps
O Fiber Recruitment
O Fast-twitch fibers
Biomechanics
1st Pull 2nd Pull Catch Phase
1st Pull
O Pull barbell up to
knees
O Keep shoulders over
bar, butt back
O Slowest movement
**2nd Pull**
O Extend hips/Jump
O Shrug shoulders
O Very explosive
movement
(generates most of
the power)
Catch Phase
O Drop under bar
O Rotate shoulders
forward/stick elbows
out
O Catch bar on
shoulders
Slow-Mo
Physics Assumptions
O All force (tension in arms) is parallel to the motion of the bar (straight up)
O All energy produced is transferred to the bar
O Bar is in “free-fall” during catch phase
FT
F
g
Work & Power
O Work
W = = ΔE
W =
O Power
P =
F ×dyò
Favg × (Dh) =1
2m(Vf
2 -Vi2 )+mg(Dh)
W
Dt
Force Calculation
Work = ΔE =
1
2m(Dv)2 +mg(Dh)
=1
2(52.16)(3.3522 -0)+ (52.16)(9.8)(0.9424) = 775Joules
Favg ×(Dh) = 775J
Favg = 775J(.9424m)
= 822N
Favg = FT -mg = 822N
FT = 822N + (52.16)(9.8) =1333N
Power Output by Pull
1st Pull
O Δh = 0.364 m
O Vi = 0 m/s
O Vf = 0.854 m/s
O Δt = 0.531 s
Work = 205 J
Power = 386 W
2nd Pull
O Δh = 0.579 m
O Vi = 0.854 m/s
O Vf = 3.352 m/s
O Δt = 0.356 s
Work = 570 J
Power = 1601 W
The Deadlift
O Very similar to clean
O Includes 1st and 2nd
pulls
O No explosion in 2nd
pull
O No catch phase
O Emphasizes strength
over power
Power Clean Deadlift
O Work = ΔKE + ΔU
=
=
= 775 Joules
O Power = W/Δt
=(775 J)/(.887 s)
= 874 Watts
O Force
Favg = 1333 N
O Work = ΔU
=
=
= 363 Joules
O Power = W/Δt
= (363 J)/(.812 s)
= 447 Watts
O Force
Favg = 1022 N
1
2m(Dv)2 +mg(Dh) mg(Dh)
1
2(52.16)(3.352)2 + (52.16)(9.8)(0.9424) (52.16)(9.8)(0.7102)
*Using the same weight*
Conclusions
O Power Clean
O Faster Movement
O Explosive 2nd pull
O Uses lighter weights
O Recruits fast-twitch
muscles in the posterior
chain
O Generates more POWER
O Deadlift
O Slower Movement
O No explosion in 2nd pull
O Uses heavier weights
O Recruits slow-twitch
muscles in posterior
chain
O Capable of generating
more FORCE