Document Detail

A mechanical comparison of linear and double-looped hung supplemental heavy chain resistance to the back squat: a case study.
MedLine Citation:
PMID:  19996780     Owner:  NLM     Status:  MEDLINE    
A relatively new and scarcely researched technique to increase strength is the use of supplemental heavy chain resistance (SHCR) in conjunction with plate weights to provide variable resistance to free weight exercises. The purpose of this case study was to determine the actual resistance being provided by a double-looped versus a linear hung SHCR to the back squat exercise. The linear technique simply hangs the chain directly from the bar, whereas the double-looped technique uses a smaller chain to adjust the height of the looped chain. In both techniques, as the squat descends, chain weight is unloaded onto the floor, and as the squat ascends, chain weight is progressively loaded back as resistance. One experienced and trained male weight lifter (age = 33 yr; height = 1.83 m; weight = 111.4 kg) served as the subject. Plate weight was set at 84.1 kg, approximately 50% of the subject's 1 repetition maximum. The SHCR was affixed to load cells, sampling at a frequency of 500 Hz, which were affixed to the Olympic bar. Data were collected as the subject completed the back squat under the following conditions: double-looped 1 chain (9.6 kg), double-looped 2 chains (19.2 kg), linear 1 chain, and linear 2 chains. The double-looped SHCR resulted in a 78-89% unloading of the chain weight at the bottom of the squat, whereas the linear hanging SHCR resulted in only a 36-42% unloading. The double-looped technique provided nearly 2 times the variable resistance at the top of the squat compared with the linear hanging technique, showing that attention must be given to the technique used to hang SHCR.
Kurt R Neelly; Joseph G Terry; Martin J Morris
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of strength and conditioning research / National Strength & Conditioning Association     Volume:  24     ISSN:  1533-4287     ISO Abbreviation:  J Strength Cond Res     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2009-12-31     Completed Date:  2010-03-15     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9415084     Medline TA:  J Strength Cond Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  278-81     Citation Subset:  IM    
Department of Physical Therapy and Health Science, Bradley University, Peoria, Illinois, USA.
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MeSH Terms
Biomechanics / physiology
Movement / physiology
Resistance Training / instrumentation,  methods*
Weight-Bearing / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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