PMID- 23259239
OWN - NLM
STAT- MEDLINE
DCOM- 20130110
LR  - 20190117
IS  - 1476-3141 (Print)
IS  - 1476-3141 (Linking)
VI  - 11
IP  - 4
DP  - 2012 Nov
TI  - The effects of load on system and lower-body joint kinetics during jump squats.
PG  - 492-506
AB  - To investigate the effects of different loads on system and lower-body kinetics 
      during jump squats, 12 resistance-trained men performed jumps under different 
      loading conditions: 0%, 12%, 27%, 42%, 56%, 71%, and 85% of 1-repetition maximum 
      (1-RM). System power output was calculated as the product of the vertical 
      component of the ground reaction force and the vertical velocity of the bar 
      during its ascent. Joint power output was calculated during bar ascent for the 
      hip, knee, and ankle joints, and was also summed across the joints. System power 
      output and joint power at knee and ankle joints were maximized at 0% 1-RM (p < 
      0.001) and followed the linear trends (p < 0.001) caused by power output 
      decreasing as the load increased. Power output at the hip was maximized at 42% 
      1-RM (p = 0.016) and followed a quadratic trend (p = 0.030). Summed joint power 
      could be predicted from system power (p < 0.05), while system power could predict 
      power at the knee and ankle joints under some of the loading conditions. Power at 
      the hip could not be predicted from system power. System power during loaded 
      jumps reflects the power at the knee and ankle, while power at the hip does not 
      correspond to system power.
FAU - Moir, Gavin L
AU  - Moir GL
AD  - Exercise Science Department, East Stroudsburg University, East Stroudsburg, PA 
      18301-2999, USA. gmoir@po-box.esu.edu
FAU - Gollie, Jared M
AU  - Gollie JM
FAU - Davis, Shala E
AU  - Davis SE
FAU - Guers, John J
AU  - Guers JJ
FAU - Witmer, Chad A
AU  - Witmer CA
LA  - eng
PT  - Journal Article
PL  - England
TA  - Sports Biomech
JT  - Sports biomechanics
JID - 101151352
SB  - IM
MH  - Adolescent
MH  - Ankle Joint/*physiology
MH  - Biomechanical Phenomena
MH  - Exercise/*physiology
MH  - Hip Joint/*physiology
MH  - Humans
MH  - Kinetics
MH  - Knee Joint/*physiology
MH  - Male
MH  - Resistance Training
MH  - Young Adult
EDAT- 2012/12/25 06:00
MHDA- 2013/01/11 06:00
CRDT- 2012/12/25 06:00
PHST- 2012/12/25 06:00 [entrez]
PHST- 2012/12/25 06:00 [pubmed]
PHST- 2013/01/11 06:00 [medline]
AID - 10.1080/14763141.2012.725426 [doi]
PST - ppublish
SO  - Sports Biomech. 2012 Nov;11(4):492-506. doi: 10.1080/14763141.2012.725426.