Muscular Analyses of Weight Training Exercises

Question & Answer

ExRx.net > Questions > Q&A

Target Muscle of Rollout

Can you tell me why Wheel Rollout shows hip flexor as its target muscle, whereas the Stability Ball Rollout suggested this movement should be for the Rectus Abdominis?

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 Lower Ab Myth.

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 and Stability Ball Rollout.


Pullover's Target Muscle

Barbell PulloverFirst 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 latissimus dorsi.

Also see other Chest Exercise Questions and Answers.


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 think?

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 bent 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 presses.

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.


Exercising Short Head of Hamstrings

Kneeling Leg CurlYour 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 machine?

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 Deadlift

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 the Romanian Deadlift.

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?

DeadliftYou 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 difference?

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.


Low Back Fatique During Good Mornings

I tried the hamstring exercise titled Smith Good Morning, and I was using my lower back some (it seemed), does this mean my form was off?

The lower back, or erector spinae muscles are isometrically contracted during the good morning. You may begin feeling it a bit more in the hamstring muscles as you continue with it over the weeks. Your lower back should be kept straight through out the Good Morning. You could always have some one look at your form. It is common, though, to feel an exercise in your "weakest link". As the lower back becomes more conditioned, you may later feel it in the target muscle. If you are performing a split program, consider performing a leg curl for your first hamstring movement and the good morning (or any hamstring exercise involving hip extension) as your second movement. This will pre-fatigue the hamstrings so you may feel it a bit more in these muscles.


Bastardized Cable Seated Row Apparatus

Cable Seated Row with legs straightMy new gym does not have a low back machine that allows articulation through the spine. I have tried the seated cable row as described on your site but my spine only bends slightly just before the weight bottoms out.

Some weight training manufacturers have lengthened the cable on their cable seated row machine so users can only perform the straight back version, presumably over concern of the safety of the spine articulating during the cable row at least for some frail uninformed individuals that may find their way onto their machines. Another possibility is you have extremely flexible hamstrings allowing you greater than normal anteriorly rotation of the hips so your spine back does not have the opportunity to flex forward. In any case, you can try one or more of these options as a workaround:

  • use a shorter cable attachment, if available
  • perform the exercise on a standard low pulley cable
  • keeping your knee straight during the cable row (as pictured)

If you perform the exercise on standard low pulley cable instead of a dedicated seated cable row machine, you will need to find something flat [weight plate(s), aerobics step, etc] to place at the base of the frame to keep your feet from sliding forward. Alternatively, you can straddle a bench positioned in front of the low pulley cable. Some benches accommodate your feet to be positioned on the bench's base with your knees slightly bent.


Spider Curl

Are there any differences between conventional Preacher Curls, as demonstrated at ExRx.net and so called Spider Curls, performed on the opposite vertical surface of a preacher bench? I am mainly concerned whether this change makes biceps the target muscle, or brachialis remains target muscle as in the conventional preacher curls. Any further comments on Spider Curls (regarding their injury potential, active insufficiency of the short head, etc.) would be highly appreciated as well.

Spider curls were popularized by old time trainer Vince Gironda. According to Larry Scott (first Mr Olympia), Vince Gironda developed a unique specialized spider bench. It included a narrow chest pad on a 15 degree bench at the top end of the bench in the form of a cross. The exerciser lies prone with arms hanging over the top of the cross and the back of the arms supported by the arm rests. Grip is about 8 inches (20 cm) apart with a false grip (thumbs and fingers on the same side of the bar). The bar is curled all the way up to the chin and down again.

Another old design apparently did not have the longer bench for the body to rest upon.

For those without these specialized benches, the exercise had been traditionally performed off the upper end of an elevated bench as depicted in the Prone Incline Curl, also known as a Spider Curl.

As your description depicts, Spider Curls have also been adapted to be performed off the opposite end of a preacher bench, thereby blurring the distinction between this variation and preacher curls.

When the spider curl is performed on a low angled incline bench, the shoulder is flexed even greater than a preacher curl or a spider curl performed off the vertical side of a preacher bench. With greater shoulder flexion, the short (inner) head of the biceps experiences is placed in an even higher degree of active insufficiency, thereby emphasis on long (outer) head of the biceps and the underlying brachialis to a greater extent as compared to preacher curl or even the spider curl performed down the opposite side of a preacher curl.

The degree of shoulder flexion is the same when comparing a preacher curl to a spider curl on the opposite side of a preacher bench. The largest difference is in the resistance curve, which is only slightly different. The resistance curve of a preacher curl begins at a slighty greater effort at the beginning and ends with a slightly lower effort at the end due to the sublet varying paths the weights travel against gravity when the arm is placed on an angled surface versus a vertical surface.


What exercises work the Sartorius?


Main Menu | Weight Training Menu | Pull-up Analysis | Exercise Safety | Speak to an Expert