Conference PaperPDF Available

CHANGES IN GLUTEUS MAXIMUS AND BICEPS FEMORIS MUSCLE ACTIVATION DURING THE GLUTE-HAM RAISE

Authors:

Abstract

Introduction: The hip extensors (gluteus maximus (GMax) and hamstrings) and knee flexors (hamstrings) play an important role in enhancing performance and reducing injury risk, during athletic tasks that require rapid force development and absorption. It is important, therefore, to accurately determine the level of activation of these muscles, via electromyography (EMG), during resistance training exercises and examine the changes across different phases of an exercise, to inform exercise prescription. Although previously researchers have reported very high-normalized EMG values (100-200% maximum voluntary isometric contraction (MVIC)) for the hamstrings, during the razor curl, these values may be elevated due to the use of suboptimal normalization techniques. The glute-ham raise (GHR) is an alternative exercise to train the GMax and hamstring muscles; however, no study has compared EMG amplitude across the phases of the exercise. PURPOSE: To determine the changes in EMG of the GMax and BF across the phases (phase 1-knee extension; phase 2-hip flexion; phase 3-hip extension; phase 4-knee flexion) of the GHR. METHODS: Subjects (n = 11; age = 23±4 years, height = 175.95±6.9 cm; mass = 75.15±9.65 kg) had EMG electrodes placed on the GMax and BF muscles in accordance with SENIAM guidelines. Subjects performed three maximum isometric voluntary contraction (MVIC) trials during knee flexion and hip extension using an isokinetic dynamometer; in order normalize the EMG during the four phases of a glute-ham raise. EMG data were analyzed in a bespoke Excel spreadsheet, identifying the four phases based on thresholds of >2 standard deviations + mean EMG acquired during periods of residual EMG. GMax activation was normalized to hip extension MVIC, while BF activation was normalized to hip extension MVIC for phases 2 and 3 and to knee flexion MVIC for phases 1 and 4. Data were compared across phases using a one-way ANOVA with Bonferroni post hoc analyses, or non-parametric equivalent. Cohen's d effect sizes were also calculated to determine the magnitude of differences between phases.


 !"#$%&' "(&"()"
Introduction:$%*#+"+,-&+(!*$(+,!*.!#/!(+$#-+.!#/
0#1*"+,!(+$#-+.%&!'!#$(%"!#"&$##!# $#-%)"(!# !#/
/ $#- $#2' $+0/$#-!&$ !+0+ ! 3$ !%$/ )" /4&"%(#
!#/!+"%$"#$+ $(%"!# )""! !&' /($# &4&")
! $4!$"# ") + (+ &+ 4$! & "('"-!%' ,. /$#- +$+!# 
!$#$#- * $++ !#/ *!($#  !#-+ ! "++ /$5# %!++ ") !#
* $+ " $#)"( * $+ %+ $%$"#&"-%4$"+&'+! + !4
%"/  4'  $-#"(!&$6/    4!&+  ,788988:  (!*$((  4"&#!'
$+"($ "#! $"# ,.. )"  !(+$#-+ /$#-  !6" & +
4!&+(!'&4!//"+")+"%$(!&#"(!&$6!$"# #$3+
 -&!( !$+ ,. $+ !# !&#!$4 * $+ " !$#  !* !#/
!(+$#-(+ &+;"<4#"+/'!+ "(%!/!(%&$/! "++
%!++ ")  * $+ PURPOSE: " /($#  !#-+ $#  ") 
!*!#/! "++%!++,%!+70#*#+$"#;%!+9=$%1*$"#;
%!+  >  =  $%  *#+$"#;  %!+  ?  =  0#  1*$"#.  ")     METHODS:
2 + ,# @ 77; !- @ 9>A? '!+ $- @ 7BCDCAED (; (!++ @
BC7CADEC 0-. !/  & "/+%&! / "#  !* !#/  (+ &+ $#
! "/!#  <$  -$/&$#+ 2 + %)"(/  (!*$((
$+"($ 4"&#!' "#! $"# ,. $!&+ /$#- 0# 1*$"# !#/ $%
*#+$"#+$#-!#$+"0$#$ /'#!("(;$#"/#"(!&$6/$#-
)"%!++")!-&!(!$+/!!<!#!&'6/$#!+%"0* &
+%!/+  $/#$)'$#-   )"  %!++  !+/  "#  +"&/+  ")  F9  +!#/!/
/4$!$"#+ G (!#  ! 3$/ /$#- %$"/+ ") +$/!&  !*
! $4!$"# <!+ #"(!&$6/ " $% *#+$"#  <$&  ! $4!$"# <!+
#"(!&$6/"$%*#+$"#)"%!++9!#/>!#/"0#1*$"#)"
%!++7!#/?!!< "(%!/! "++%!+++$#-!"#<!'<$
"#)"#$ %"+ " !#!&'++ " #"#%!!($ 3$4!&# "#H+ / 5 
+$6+< !&+" !& &!/ "/($#(!-#$/") /$5# +<#
%!++#a priori!&%!&4&<!++!p I88CRESULTS:$-+%!0
)" !*!#/" //$#- %!+?<$ <!++$-#$J !#&'-!!#
!&&"%!++)",pI8887.!#/-!!#%!++9!#/?)"
!*,pK8887.,!&7.!#!*<!++$-#$J !#&',pI8887.&"<$#
%!+ 9 "(%!/ " !&& " %!++ ,!& 7. !#   <!+ -!+
/$#- %!+ > !&"- $+ <!+ "#&' +$-#$J !#&' -! ,p I8887.  !#
/$#- %!+ 9 ,!&  7. CONCLUSIONS:  -&!(!$+ &!/+ " #!
(!*$(!&! $4!$"# ") ,FBC:. $#!&& %!+9<!++(!*$(!&
 ! $4!$"# ")  !* $+ 4$/# ! "++ !&& %!++ PRACTICAL
APPLICATIONS:-&!(!$+(!'#J $!&$#(!*$($6$#-! $4!$"#
")+% $!&&'/$#-%!+?&$0&'%"4$/+!%""!$#$#-+$(&+
)"!*
!&7L"(%!$+"#")#"(!&$6/! "++%!++")-&!(!$+
$ %("$+
!0 !
#  :
!+7
4+!+
9
!+7
4+!+
>
!+7
4+!+
?
!+9
4+!+
>
!+9
4+!+
?
!+>
4+!+
?
p d p d p d p d % / % /
!+
7
BEC
8
9D
DM
>?
8:
88
8>
78
?M
8?
9E
8M
87
88
8?
8C
D>
I
888
7
8E
CB
I
888
7
8?
ME
I
888
7
8B
9D
!+
9
CD7
?
98
DD
?C
B:
!+
>
BD7
B
97
DB
?9
D:
!+
?
78C
7D
>C
9D
?9
8:
!# !
#  :
!+7
4+!+
9
!+7
4+!+
>
!+7
4+!+
?
!+9
4+!+
>
!+9
4+!+
?
!+>
4+!+
?
p d p d p d p d p d p d
!+
7
C8?
7
98
B?
CM
7:
87
?9
8D
9B
87
B8
8E
BM
88
?C
8B
87
I
888
7
8C
B7
887
D
8C
D7
788
8
78
9>
!+
9
?7D
B
7E
DC
9E
>:
!+
>
CDB
8
CD
B8
?C
C:
!+
?
CCB
E
7E
?7
??
8:
&+!*$(+
!0 
!#  :
!+7
4+!+
9
!+7
4+
!+>
!+7
4+
!+?
!+9
4+!+
>
!+9
4+!+
?
!+>
4+!+
?
p d p d p d p d p d p d
!+
7
7B
EM
D9
C
M>?
:
I
888
7
8
D>
7
8
87
D
8>
8E
8D
MB
8
98
M
888
>
8?
M?
I8
887
8D
BM
8
88
7
7B7
>
!+
9
D?
7
MC
8
7>?
>:
!+
>
7?
?9
77
D7
BBD
:
!+
?
98
88
79
B>
787
B:
!
#

!#  :
!+7
4+!+
9
!+7
4+
!+>
!+7
4+
!+?
!+9
4+!+
>
!+9
4+!+
?
!+>
4+!+
?
p d p d p d p d p d p d
!+
7
77
9D
BD
D
EBE
:
I
888
7
8
B7
C
8
??
C
88
DB
8M
>>
8
88
B
I
888
7
8B
9D
I
888
7
8B
>D
8
CB
8
7BC
8
!+
9
E>
8
CB
B
D>M
:
!+
>
79
7E
DB
M
BD7
:
!+
?
77
>C
BB
?
B88
:
ResearchGate has not been able to resolve any citations for this publication.
ResearchGate has not been able to resolve any references for this publication.