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8/16/2019 KINE 4472 - Presentation
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Muscular Contribution to Low Back Loading and Stiffness
During Standard and Suspended Push Ups
Tyson A.C. Beach, Samuel J. Howarth, Jack P. Callaghan
8/16/2019 KINE 4472 - Presentation
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INTRODUCTION
!
Why are push-up exercises performed? Increase strength or
endurance of muscles that span the upper extremity joints
!
Trunk muscle activation: labile vs. stable surfaces
!
Muscle sti
ness and joint sti
ness
!
Why this study?
!
To examine whether di
erences exist in trunk muscle activation levels
contributions to lumbar IVJ loading androtational sti
ness when standard
push-ups were compared to suspended push-ups
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METHODS
!
11 trained male volunteers
!
1 set suspended 1 set standard
push-ups (8-10 repetitions)
!
IRED’s andEMG recording
electrodes used to assess
muscle activation
!
Contribution of all spanning
muscles about each axis of each
IVJ were summed and averaged
1.83m9.4kg
AGE: 27.4
Standard Push-Up
Suspended Push-Up
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RESULTS
!
Muscles of the abdominal wall andlatissimus dorsi had increased
mean and peak muscle activation during suspended push-ups
!
As a direct result of increased muscle activation levels, lumbar
L4/L5 compressive forces and lumbar intervertebral joint
rotational sti
ness were also significantly greater
!
No significant di
erences in linked-segment model outputs or lumbar spine posture
0
10
20
30
40
50
60
RECTUS
ABDOMINIS
EXTERNAL
OBLIQUES
INTERNAL
OBLIQUES
LATISSIMUS
DORSI
% o
f M V I C
STANDARD SUSPENDED
Copyright © 2009 Pearson Education Inc.
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DISCUSSION
!
Due to the instability of a labile surface, the abdominal muscles illicit
hoop stresses to increase stability in the lower spine
!
Abdominal activation during push-up can approach or exceed
magnitudes recorded during more conventional abdominal
exercises
!
Prescribe push-ups as a form of abdominal exercise
!
Lower back compression with no deviation from neutral
!
No participant experienced L4/L5 IVJ shear loads in excess of 1 kN
!
Suspended push-ups may increase the risk of low-back injury for
some individuals
!
Compressive loads exceeded 3.4 kN limit set by NIOSH
! Study is based on outputs of a biomechanical model
!
Sensitive to di
erences in anatomical parameters
!
This model was constructed based on male-based data set
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CONCLUSION
!
Push-up exercise presents an abdominal muscle challenge
!
More pronounced when the hands were interfaced with a labile support
surface
! Compared to standard push-ups, suspended push-ups provide a
superior abdominal muscle challenge based on measured
activation levels and lumbar IVJrotational sti ness
!
For individuals unable to tolerate large magnitude low-back
compressive loads, benefits gained by incorporating suspended
push-ups may be outweighed by the potential risk of overloading
low-back tissues
!
Future studies examining upper extremity biomechanics while
performing push-ups on labile support surfaces to provide a more
complete justification for their use in resistance training programs
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