PMID- 27669187
OWN - NLM
STAT- MEDLINE
DCOM- 20171212
LR  - 20181202
IS  - 1533-4287 (Electronic)
IS  - 1064-8011 (Linking)
VI  - 31
IP  - 7
DP  - 2017 Jul
TI  - Muscle-Specific Effective Mechanical Advantage and Joint Impulse in 
      Weightlifting.
PG  - 1905-1910
LID - 10.1519/JSC.0000000000001658 [doi]
AB  - Kipp, K, and Harris, C. Muscle-specific effective mechanical advantage and joint 
      impulse in weightlifting. J Strength Cond Res 31(7): 1905-1910, 2017-Lifting 
      greater loads during weightlifting exercises may theoretically be achieved 
      through increasing the magnitudes of net joint impulses or manipulating the 
      joints' effective mechanical advantage (EMA). The purpose of this study was to 
      investigate muscle-specific EMA and joint impulse as well as impulse-momentum 
      characteristics of the lifter-barbell system across a range of external loads 
      during the execution of the clean. Collegiate-level weightlifters performed 
      submaximal cleans at 65, 75, and 85% of their 1-repetition maximum (1-RM), 
      whereas data from a motion analysis system and a force plate were used to 
      calculate lifter-barbell system impulse and velocity, as well as net extensor 
      impulse generated at the hip, knee, and ankle joints and the EMA of the gluteus 
      maximus, hamstrings, quadriceps, and triceps surae muscles. The results indicated 
      that the lifter-barbell system impulse did not change as load increased, whereas 
      the velocity of the lifter-barbell system decreased with greater load. In 
      addition, the net extensor impulse at all joints increased as load increased. The 
      EMA of all muscles did not, however, change as load increased. The load-dependent 
      effects on the impulse-velocity characteristics of the lifter-barbell system may 
      reflect musculoskeletal force-velocity behaviors, and may further indicate that 
      the weightlifting performance is limited by the magnitude of ground reaction 
      force impulse. In turn, the load-dependent effects observed at the joint level 
      indicated that lifting greater loads were due to greater net extensor impulses 
      generated at the joints of the lower extremity and not greater EMAs of the 
      respective extensor muscles. In combination, these results suggest that lifting 
      greater external loads during the clean is due to the ability to generate large 
      extensor joint impulses, rather than manipulate EMA.
FAU - Kipp, Kristof
AU  - Kipp K
AD  - 1Department of Physical Therapy-Program in Exercise Science, Marquette 
      University, Milwaukee, Wisconsin; and 2Department of Health Science, Central 
      Oregon Community College, Bend, Oregon.
FAU - Harris, Chad
AU  - Harris C
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Strength Cond Res
JT  - Journal of strength and conditioning research
JID - 9415084
SB  - IM
MH  - Adult
MH  - Ankle Joint/physiology
MH  - Biomechanical Phenomena
MH  - Exercise/physiology
MH  - Hip Joint/physiology
MH  - Humans
MH  - Knee/physiology
MH  - Knee Joint/physiology
MH  - Lower Extremity/physiology
MH  - Male
MH  - Muscle, Skeletal/*physiology
MH  - Weight Lifting/*physiology
MH  - Young Adult
EDAT- 2016/09/27 06:00
MHDA- 2017/12/13 06:00
CRDT- 2016/09/27 06:00
PHST- 2016/09/27 06:00 [pubmed]
PHST- 2017/12/13 06:00 [medline]
PHST- 2016/09/27 06:00 [entrez]
AID - 10.1519/JSC.0000000000001658 [doi]
PST - ppublish
SO  - J Strength Cond Res. 2017 Jul;31(7):1905-1910. doi: 10.1519/JSC.0000000000001658.