Target Muscle of Rollout
Can you tell me why Wheel
Rollout shows hip flexor as its target muscle, whereas the
Ball Rollout suggested this movement should be for the Rectus
It is difficult to attribute one target muscle
to these exercises, particularly the Stability Ball Rollout.
As mentioned, the abdominal muscles
are exercised isometrically
in both these movements, since only a small degree of waist flexion
occurs under resistance.
However, no appreciable hip flexion occurs in the Wheel Rollout,
whereas, significant hip flexion occurs in the Kneeling Stability
Ball Rollout. The Wheel Rollout has been classified as a hip
flexor movement along with all the other hip
flexor movements that also exercise the abdominals isometrically
(eg: Leg Raise). It should be noted, all hip flexor exercises
utilizing bilateral movement activate abdominal muscles isometrically,
hence hip flexor classification of those exercises. Also see
To complicate matters, shoulder extension predominates in
both movements, so much that some may consider them akin to a
pullover or straight arm pulldown exercise, however, we believe
most people performing the Stability Ball Rollout exercise intend
to work the Abdominals, at least isometrically, so it has been
classified as such for the Stability Ball Rollout, since it could
not be listed as a hip flexor movement.
We rarely classify an isometric target muscle for a dynamic
exercise, but we have done so in the cases of the Deadlift
Pullover's Target Muscle
of all i need to say to all of you big thanks for all the thing
i lern from this amazin site. But (there's allways a but :) )
i have some problem of knowing something about the "pullover"
exercise. I know that pullover is a exercise for the target muscle
"Latissimus Dorsi" and so it say's in the site. When
i look at pullover with, cable, Barbell and Lever. But when i
look at pullover with Dumbbell i've paying attention that the
target muscle is "Pectoralis Major (Sternal Head)".
And i can't understand why, so i realy want you to tell me why,
or that it's a mistake or something.
The pullover exercises both muscles. The chest is emphasized
with the shoulders internally rotated (elbows out). This is the
posture is assumed when grasping the dumbbell with both hands
as with the Dumbbell
Pullover. The clavicular pectoralis major has a more favorable
line of pull in this posture. With the other apparatuses the
shoulders are more in a neutral position where there is a more
favorable pull with the lats.
Pullover Works Serratus Anterior?
I would appreciate your feedback about putting the serratus
anterior muscles as primary muscles in the bent arm pullover
part of the demo site as i think this is important, what do you
If you note the function of the serratus
anterior, you will see these motions are virtually the opposite
of the motion of the scapula during the concentric phase of the
arm pullover. Contrary to what certain books suggest, serratus
anterior does not play an active role in this motion. In fact,
Serratus Anterior is involved in the opposite movement, such
as in front
raise. During pullover, serratus anterior could be activated
if the shoulders are raised from the bench, somewhat like at
the end of a pushup. The Serratus Anterior is also known as the
boxer's muscle because of the movement during the end of a punch.
The Serratus Anterior is also involved during overhead
I can only speculate why this misconception came about. Older
exercise guides (Pre-1970s) suggested performing pullovers, while
breathing deeply could expand the rib cage, particularly if performed
in the teen years. The External Intercostals (involved in rib
elevation) and the Internal Intercostals (involved in rib elevation
during inhalation and rib depression during exhalation) are somewhat
in proximity to the Serratus Anterior; but this is only my theory
to explain a misguided idea.
Chest Dip and Triceps Dip Differences
little curious to know what is the difference between the Chest
Dip and the Triceps Dip? For Chest Dip we should bend forward
more or so?
You should be able to see from the instructions the differences
include the grip on the bar and the positioning of the arms and
legs. On the Chest
Dip, you place your hands diagonal on the bars to facilitate
the elbows flaring outward, whereas, on the Triceps
Dip you have a more standard grip on the bar. On Chest Dip,
you bend your hips and knees whereas on the triceps dip, your
hips are straighter so your body will be more upright.
Pectoralis Major Adducts and Abducts
In shoulder articulations, pectoralis major (clavicular
part) appears as a weak adductor as well as a weak abductor.
How is this possible - that a muscle behaves in the same way
in contrasting activities?
When the shoulder is externally rotated, the clavicular
pectoralis assists in abduction; particularly beyond where
the arm is already abducted 90º. (Thompson & Floyd,
Manual of Structural Kinesiology) This muscle is even more involved
in abduction, or pushing an object overhead in an individual
with a deep rib cage (barrel chest) and/or with their chest held
high, as in the military press.
The clavicular pectoralis assist the sternal
pectoralis in adduction, particularly when the shoulder is
internally rotated (Above reference and Moore, Clinically Oriented
Anatomy) where the arm is already adducted 90º. It is even
more involved when the adduction is accompanied by slight horizontal
flexion as with bending over slightly when performing the chest
dip or standing cable fly.
Traps with Back or Shoulders?
I noticed that the middle and lower trapezius muscles are
worked in back exercises, such as one arm dumbell rows, but that
the upper traps are worked during deltoid exercises such as the
military press. My question is when to do shrugs, with shoulders
or with back. Is it okay to work the middle and lower traps with
rowing exercises during my back workout, and then do shrugs to
hit the upper traps during my shoulder workout, or should I keep
lower, middle, and upper traps all together on one day?
Either way is acceptable. The upper trap worked isometrically
as a stabilizer on most front and side delt exercises. With a
split program, it is common to have movements that exercise muscles
that have already been worked on another day. For example, many
back and lat exercises involve the chest. The idea is to minimize
overtraining those body parts that are prone to injury, like
the lower back. Don't do squats on day and straight-leg deadlifts
the next day, see Lower
Since I have been weight training I have noticed my left
pec is growing faster than my right. I have also noticed the
right side of my coller bone is slightly higher than the left
side. Do you think this could be the cause and if so do you have
any ideas on targeting that muscle better.
Consult a physical therapist if you have had an old injury
that has altered your range of motion, posture, or muscle function.
They may prescribe specific stretches and exercises for postural
muscles. Alternatively, you may consider seeking a physiotherapist
that practices ART (active release technique) or posturology.
Make certain your exercise form is close to symmetrical on
your bench, incline and shoulder press. Have a few spotters look
at your form for differences on each side. If there is a difference,
use only the weight you can manage in symmetrical form, increasing
only when you are able to manage near symmetrical form. You will
need continuous feedback to correct your form at first. Incidentally,
most studies have demonstrated that extra sets do not develop
significant differences in muscular size or strength so an additional
set of the exercises you are currently performing will probably
not be that effective.
Most people have subtle differences between their right and
left sides. I have a similar chest asymmetry with the right scapula
slightly anterior. In addition, I even have 2 abs on one side
and 3 abs on my other side. Next time you see a bodybuilding
publication take a close look at difference between these individuals
right and left sides. Even those bodybuilders who are noted for
their symmetry have differences. They just know how to hide it.
If thinking about competing in bodybuilding, understand you will
look more symmetrical in asymmetrical poses.
Also see Structual Symmetry.
Weight Training Exercise Utility Classification
Some execises are categorized as "Basic or Auxillary".
Does that mean some authorities consider it basic, and others
auxillary, or you can make it either one (depending on the way
you do it)?
The latter. The classifications can be seen as a continuum.
An exercise utility is also dependent upon the inclusion of other
exercises. For example, an incline bench press is an auxiliary
exercise in the context of a full body routine, but a basic exercise
in a split program. A step up is an auxiliary exercise when included
with squats, but an auxiliary exercise if a leg extension is
performed instead. You will find the definitions
in the glossary eludes to relative characteristics.
Exercising Short Head of Hamstrings
muscular analysis of the hamstrings says that the short head
of the biceps femoris is involved in knee flexion but not hip
extension. I am currently using straight leg deadlifts for my
hamstrings since I lift at home and don't have access to a leg
curl machine. Is it necessary to exercise the short head of the
biceps femoris? Is there any way to do so without a leg curl
You should be fine performing a straight leg deadlift instead
of a leg curl for a month or so. You can, however perform a leg
curl like exercise on back with an exercise ball under your lower
leg using your body weight. There are also lying or standing
cable leg curls to consider. You get other ideas on our forum.
Target Muscle of Straight Leg
Excellent Site! I had a quick question regarding the "Target
Muscle" specified in the "Smith Straight Leg Deadlift."
On your site you have two pages for the Smith Straight Leg Deadlift
. . . one under Hamstrings,
and the other for Erector
Spinae. Which page is accurate for the "Target Muscle?"
Both pages seem to contain the same information, with the Target
and Synergist Muscle swapped. Also, the Smith
Deadlift (or what appears to be the Romanian Deadlift) Muscle
Target is the Erector Spinae and not the Hamstrings? Many thanks!
Most exercises work multiple muscles. The Straight-leg deadlift
just happens to work both the low back and hamstrings about the
same, since torque forces occur both through the spine and hip.
People may report they feel fatigued (or soreness the day after)
more in one or the other depending on what is likely 'weaker'.
You will find other cases of this in other exercises.
Some may argue the deadlift (knees bending on descent) is
a near total body exercise. You will also see the deadlift listed
as a glute exercise (see link under comments) although most people
never feel their glutes working partly because it is the most
powerful muscle in the body and other muscles are working relatively
so much more intensely, like the low back.Although it acts as
a stabilizer, it is typically the muscle that is most taxed.
The hamstring's ability to work at the hip is severely hamstrung
(pun intended), since the knees bend as the hips bend, although
not as much as a squat, but more than the Romanian Deadlift.
On the Deadlift page, you can click on 'dynamic stabilizer' header
just above hamstring to understand this concept more fully. Also,
notice the hips travel much lower on Deadlift as compared to
Most classification system may not be perfect (most requiring
notations and subnotations), but we can still use it as a tool
for understanding general concepts as well as way to referencing
large lists, such as exercises :-)
Dealift for Glutes -vs- Low Back?
list two deadlifts (targeting
Glutes and another targeting
Erector Spinae) which are shown to be exactly the same, but
each is missing the others muscle group. Any explanation on the
Several exercises target one of two muscles depending on your
perspective. Sometimes, there may be subtle differences in execution
and biomechanics as in the squat, the bodybuilding-style
squat is more Quadriceps centric, whereas, the Powerlifting-style
squat emphasizes the stonger Gluteus Maximus. You can see
on the exercise you cited, the Deadlift, the target muscle could
either be considered a glute movement (where the greatest dynamic
force is generated) or the low back exercise (where the greatest
isometric force is generated). There are really no differences
between the versions shown, only a difference on how the Deadlift
could be classified.
New Kinesiology Terms
Where I can read scientific articles regarding the concept
I coined the term 'dynamic
stabilizer' many years ago to describe a biarticulate muscle
that shortens at one joint and lengthens an adjacent joint so
there is practically no net contraction of that muscle. At the
time, I could not find a term for a muscle with this characteristic
even after consulting with professors of biomechanics.
The most cited example of this concept is the hamstring's stabilizing
effects on the knee, counteracting the powerful anterior dislocating
effects of the quadriceps during closed
chained pushing movements, such as with the squat and leg
weakness is of particular concern when there has been a compromise
to the anterior cruciate ligament of the knee.
To fully understand this concept, it helps to study how the force
vectors act within the structures of the body. I remember seeing
a vector diagram of these counteracting forces in a biomechanics
text book (Kreighbaum, E., Barthels, K.M., (1996). Biomechanics;
A Qualitative Approach for Studying Human Movement, Allyn &
Bacon, 4.) but to my understanding, it incorrectly illustrated
the true location of the fulcrum and angle of pull of the quadriceps.
I now exhibit a corrected
diagram on the Angle of Pull page.
Actually, on that diagram, I have used the corrected force vectors
and added muscle's force vectors to understand a nearly opposite
movement, open chain knee flexion, as in a lying leg curl. See
how the tibialis anterior has the ability to activate the gastrocnemius
as a synergist in knee flexion? And the Rectus Femoris has the
potential to position the hip in a more favorable position for
knee flexion, by decreasing active insufficiency of the hamstring.
I call these sort of muscle 'antagonistic
stabilizer', another term I have created because I found
no better way to describe their actions.
But if you only look at the force vectors within the purple rectangles
only, how they were originally 'intended to be viewed in that
textbook with its errors, you can use that part of the diagram
to better understand how the hamstrings can counteract the dislocation
forces of the quadriceps in a close chained leg press or squat
As you have seen on ExRx.net, you can find other examples how
other biarticulate muscles can be involved as dynamic stabilizers.
What exercises work the Sartorius?