Weight lifted during a Push-up?

[Guest guest]

Here is a little discussion which we had among our work colleagues recently.

Would any Supertrainers like to comment?

---------------

What is the weight lifted during a push-up? Can you use a bathroom scale(s)

to determine the weight lifted? What about the weight of your hands - are

you really lifting your hands?

Perhaps this is a question of force exerted vs. weight lifted (is there a

difference??..Hmmm). Additionally, perhaps the term " lifted " is causing some

confusion for some.

Background info: Force is measured in either Newtons (N) or pounds (lbs);

weight is a force, so it is also measured in N or lbs; mass is measured in

either kilograms (kg) or slugs.

I just measured my stats as follows:

Body Weight = 205 lbs

Force exerted by the body in a pushup position = 152 lbs or 676 N

Percentage of BW = 74%

Now, we know that Newton's Third Law states that for every action, there is

an equal and opposite reaction; i.e., when one body exerts a force on a

second, the second body exerts a reaction force that is equal in magnitude

and opposite in direction on the first body.

Therefore, if I HOLD a push-up position at the top of the movement, halfway

down the movement, or anywhere in between, then I am exerting 676 N against

the ground and the ground is exerting 676 N against my hands. Now, suppose I

wish to push myself up from the bottom position of the push-up. I must

accelerate my mass upward (positive acceration) and as such the force I am

exerting against the ground increases (F = ma). When this happens, the force

the ground is exerting on me also increases to the same magnitude, but

opposite direction. For this example, it may be 800 N. Anyway, the weight

lifted or the force exerted by the body in an isometric situation is 676 N.

This is the weight lifted. It makes no difference if my hands don't move off

the ground etc.

It should be noted that I am using physics to explain the external

environment created by the body against the ground. This is not the same as

the internal environment. However, the internal environment is influenced by

the joint angles, the acceleration, the intensity (%RM), the anthropometric

differences, fiber type etc. For this reason, we need expensive lab

equipment to tell exactly what is going on inside the body. To answer the

question of how much weight is being lifted though, we can simply use the

bathroom scale. Do not confuse internal muscle tension and recruitment with

external physics done by the body. The question posed and the resulting

debate was about external physics.

Now, of course, these comments are my own and reflect my current

understanding of physics and biomechanics. I'm willing to admit I'm wrong,

but I need some real info to influence me otherwise. So please, bring on the

info...I want to learn.

---------------

Here's a study whereby the researchers used a force plate (essentially a

glorified bathroom scale) to equate the load between a push-up and a bench

press. Hmmm??

Med Sci Sports Exerc 1999 Mar; 31(3):443-8

Use of EMG analysis in challenging kinetic chain terminology.

Blackard DO, Jensen RL, Ebben WP.

PURPOSE: The purpose of this study was to compare mean integrated

electromyographic values (EMG(int)) during biomechanically comparable closed

kinetic chain/fixed external load, open kinetic chain/moveable no load, and

moveable external load exercises.

METHODS: EMG(int) were obtained for the pectoralis major (PM) and the long

head of the triceps (T) during absorption and force phases of three

biomechanically comparable exercises: the push-up (PU); the bench press-load

(BP-L); and the bench press-no load (BP-NL) equated to the closed kinetic

chain/fixed external load; moveable external load; and open kinetic

chain/moveable no load conditions respectively. A force plate was used to

equate load for the PU and BP-L exercises. Ten males (24 ±4.4 yr)

participated in the three randomly ordered exercises. A pronated, closed grip

was used for all exercises. The mean integrated EMG values from three

isometric maximal voluntary contractions were used to determine a reference

EMG (EMG(MVC))for each muscle. Normalized EMG values (NEMG) were determined

by EMG(int)/EMG(Mvc) and analyzed by one-factor repeated measures ANOVA for

each muscle (PM and T) during each phase (absorption and force).

RESULTS: There was no significant difference between the equivalently loaded,

different boundary exercises (PU and BP). Statistical significance was

determined between the differently loaded, equivalent boundary exercises (BP

and BP-NL) as well as the differently loaded, different boundary exercises

(PU and BP-NL).

CONCLUSIONS: Results from this study support the theory that activities of

similar biomechanical motions and mass of loading, regardless of the boundary

condition, have comparable EMG values of primary muscle groups. In addition,

this study suggests external load is more important than boundary condition

in describing human activity.

--------------

Gabe Rinaldi

.....USA

[Guest guest]

Although the weight lifted may be thus equivocated, as you state,

what's going on the internal environment can be quite different.

Thus, I don't think considering the two exercises as equivalent is a

good idea.

The pushup itself can vary greatly in difficulty and

muscle actions emphasized, depending upon one's form. Most people

tend to achieve a large portion of their pushup ROM from movement of

the sternoclavicular joint (i.e., primarily from retracting and

protracting the scapulae).

This is MUCH easier than the way I advocate doing pushups, where the trainee

endeavors to keep the scapulae relatively stable throughout the movement,

acheiving most of the ROM through glenohumeral movement - a 'focus pushup'.

I think this way is more similar to the way a bench press is generally

performed, as the pressure of the bench bracing the back seems to

assist in stabilizing the scapulae. But again, the 'focus pushup' is

different, requiring not only more effort to stabilize the scapulae

but also to keep the entire torso rigid.

I think that developing the ability to do 'focus pushups' with excellent form

has many advantages over the bench press as a general conditioning exercise

(within the same weight range) - the primary benefits coming from

shoulder stability in the form of injury resistance and increased

ability of the shoulder to transmit/transfer forces generated by the

torso through the upper limb (punching, pushing, hitting, swinging an

implement, etc...).

Wilbanks

ville, FL

-------------

Gabe Rinaldi wrote:

> Here is a little discussion which we had among our work colleagues recently.

> Would any Supertrainers like to comment?

>

> ---------------

>

> What is the weight lifted during a push-up? Can you use a bathroom scale(s)

> to determine the weight lifted? What about the weight of your hands - are

> you really lifting your hands?

>

> Perhaps this is a question of force exerted vs. weight lifted (is there a

> difference??..Hmmm). Additionally, perhaps the term " lifted " is causing some

> confusion for some.

>

> Background info: Force is measured in either Newtons (N) or pounds (lbs);

> weight is a force, so it is also measured in N or lbs; mass is measured in

> either kilograms (kg) or slugs.

>

> I just measured my stats as follows:

>

> Body Weight = 205 lbs

> Force exerted by the body in a pushup position = 152 lbs or 676 N

> Percentage of BW = 74%

>

> Now, we know that Newton's Third Law states that for every action,

there is

> an equal and opposite reaction; i.e., when one body exerts a force

on a

> second, the second body exerts a reaction force that is equal in

magnitude

> and opposite in direction on the first body.

>

> Therefore, if I HOLD a push-up position at the top of the movement,

halfway

> down the movement, or anywhere in between, then I am exerting 676 N

against

> the ground and the ground is exerting 676 N against my hands. Now,

suppose I

> wish to push myself up from the bottom position of the push-up. I

must

> accelerate my mass upward (positive acceration) and as such the

force I am

> exerting against the ground increases (F = ma). When this happens,

the force

> the ground is exerting on me also increases to the same magnitude,

but

> opposite direction. For this example, it may be 800 N. Anyway,

the weight

> lifted or the force exerted by the body in an isometric situation

is 676 N.

> This is the weight lifted. It makes no difference if my hands

don't move off

> the ground etc.

>

> It should be noted that I am using physics to explain the external

> environment created by the body against the ground. This is not

the same as

> the internal environment. However, the internal environment is

influenced by

> the joint angles, the acceleration, the intensity (%RM), the

anthropometric

> differences, fiber type etc. For this reason, we need expensive

lab

> equipment to tell exactly what is going on inside the body. To

answer the

> question of how much weight is being lifted though, we can simply

use the

> bathroom scale. Do not confuse internal muscle tension and

recruitment with

> external physics done by the body. The question posed and the

resulting

> debate was about external physics.

>

> Now, of course, these comments are my own and reflect my current

> understanding of physics and biomechanics. I'm willing to admit

I'm wrong,

> but I need some real info to influence me otherwise. So please,

bring on the

> info...I want to learn.

>

> ---------------

>

> Here's a study whereby the researchers used a force plate

(essentially a

> glorified bathroom scale) to equate the load between a push-up and

a bench

> press. Hmmm??

>

> Med Sci Sports Exerc 1999 Mar; 31(3):443-8

>

> Use of EMG analysis in challenging kinetic chain terminology.

>

> Blackard DO, Jensen RL, Ebben WP.

>

> PURPOSE: The purpose of this study was to compare mean integrated

> electromyographic values (EMG(int)) during biomechanically

comparable closed

> kinetic chain/fixed external load, open kinetic chain/moveable no

load, and

> moveable external load exercises.

>

> METHODS: EMG(int) were obtained for the pectoralis major (PM) and

the long

> head of the triceps (T) during absorption and force phases of three

> biomechanically comparable exercises: the push-up (PU); the bench

press-load

> (BP-L); and the bench press-no load (BP-NL) equated to the closed

kinetic

> chain/fixed external load; moveable external load; and open kinetic

> chain/moveable no load conditions respectively. A force plate was

used to

> equate load for the PU and BP-L exercises. Ten males (24 ±4.4 yr)

> participated in the three randomly ordered exercises. A pronated,

closed grip

> was used for all exercises. The mean integrated EMG values from

three

> isometric maximal voluntary contractions were used to determine a

reference

> EMG (EMG(MVC))for each muscle. Normalized EMG values (NEMG) were

determined

> by EMG(int)/EMG(Mvc) and analyzed by one-factor repeated measures

ANOVA for

> each muscle (PM and T) during each phase (absorption and force).

>

> RESULTS: There was no significant difference between the

equivalently loaded,

> different boundary exercises (PU and BP). Statistical significance

was

> determined between the differently loaded, equivalent boundary

exercises (BP

> and BP-NL) as well as the differently loaded, different boundary

exercises

> (PU and BP-NL).

>

> CONCLUSIONS: Results from this study support the theory that

activities of

> similar biomechanical motions and mass of loading, regardless of

the boundary

> condition, have comparable EMG values of primary muscle groups. In

addition,

> this study suggests external load is more important than boundary

condition

> in describing human activity.

--------------

[Guest guest]

Although the weight lifted may be thus equivocated, as you state,

what's going on the internal environment can be quite different.

Thus, I don't think considering the two exercises as equivalent is a

good idea.

The pushup itself can vary greatly in difficulty and

muscle actions emphasized, depending upon one's form. Most people

tend to achieve a large portion of their pushup ROM from movement of

the sternoclavicular joint (i.e., primarily from retracting and

protracting the scapulae).

This is MUCH easier than the way I advocate doing pushups, where the trainee

endeavors to keep the scapulae relatively stable throughout the movement,

acheiving most of the ROM through glenohumeral movement - a 'focus pushup'.

I think this way is more similar to the way a bench press is generally

performed, as the pressure of the bench bracing the back seems to

assist in stabilizing the scapulae. But again, the 'focus pushup' is

different, requiring not only more effort to stabilize the scapulae

but also to keep the entire torso rigid.

I think that developing the ability to do 'focus pushups' with excellent form

has many advantages over the bench press as a general conditioning exercise

(within the same weight range) - the primary benefits coming from

shoulder stability in the form of injury resistance and increased

ability of the shoulder to transmit/transfer forces generated by the

torso through the upper limb (punching, pushing, hitting, swinging an

implement, etc...).

Wilbanks

ville, FL

-------------

Gabe Rinaldi wrote:

> Here is a little discussion which we had among our work colleagues recently.

> Would any Supertrainers like to comment?

>

> ---------------

>

> What is the weight lifted during a push-up? Can you use a bathroom scale(s)

> to determine the weight lifted? What about the weight of your hands - are

> you really lifting your hands?

>

> Perhaps this is a question of force exerted vs. weight lifted (is there a

> difference??..Hmmm). Additionally, perhaps the term " lifted " is causing some

> confusion for some.

>

> Background info: Force is measured in either Newtons (N) or pounds (lbs);

> weight is a force, so it is also measured in N or lbs; mass is measured in

> either kilograms (kg) or slugs.

>

> I just measured my stats as follows:

>

> Body Weight = 205 lbs

> Force exerted by the body in a pushup position = 152 lbs or 676 N

> Percentage of BW = 74%

>

> Now, we know that Newton's Third Law states that for every action,

there is

> an equal and opposite reaction; i.e., when one body exerts a force

on a

> second, the second body exerts a reaction force that is equal in

magnitude

> and opposite in direction on the first body.

>

> Therefore, if I HOLD a push-up position at the top of the movement,

halfway

> down the movement, or anywhere in between, then I am exerting 676 N

against

> the ground and the ground is exerting 676 N against my hands. Now,

suppose I

> wish to push myself up from the bottom position of the push-up. I

must

> accelerate my mass upward (positive acceration) and as such the

force I am

> exerting against the ground increases (F = ma). When this happens,

the force

> the ground is exerting on me also increases to the same magnitude,

but

> opposite direction. For this example, it may be 800 N. Anyway,

the weight

> lifted or the force exerted by the body in an isometric situation

is 676 N.

> This is the weight lifted. It makes no difference if my hands

don't move off

> the ground etc.

>

> It should be noted that I am using physics to explain the external

> environment created by the body against the ground. This is not

the same as

> the internal environment. However, the internal environment is

influenced by

> the joint angles, the acceleration, the intensity (%RM), the

anthropometric

> differences, fiber type etc. For this reason, we need expensive

lab

> equipment to tell exactly what is going on inside the body. To

answer the

> question of how much weight is being lifted though, we can simply

use the

> bathroom scale. Do not confuse internal muscle tension and

recruitment with

> external physics done by the body. The question posed and the

resulting

> debate was about external physics.

>

> Now, of course, these comments are my own and reflect my current

> understanding of physics and biomechanics. I'm willing to admit

I'm wrong,

> but I need some real info to influence me otherwise. So please,

bring on the

> info...I want to learn.

>

> ---------------

>

> Here's a study whereby the researchers used a force plate

(essentially a

> glorified bathroom scale) to equate the load between a push-up and

a bench

> press. Hmmm??

>

> Med Sci Sports Exerc 1999 Mar; 31(3):443-8

>

> Use of EMG analysis in challenging kinetic chain terminology.

>

> Blackard DO, Jensen RL, Ebben WP.

>

> PURPOSE: The purpose of this study was to compare mean integrated

> electromyographic values (EMG(int)) during biomechanically

comparable closed

> kinetic chain/fixed external load, open kinetic chain/moveable no

load, and

> moveable external load exercises.

>

> METHODS: EMG(int) were obtained for the pectoralis major (PM) and

the long

> head of the triceps (T) during absorption and force phases of three

> biomechanically comparable exercises: the push-up (PU); the bench

press-load

> (BP-L); and the bench press-no load (BP-NL) equated to the closed

kinetic

> chain/fixed external load; moveable external load; and open kinetic

> chain/moveable no load conditions respectively. A force plate was

used to

> equate load for the PU and BP-L exercises. Ten males (24 ±4.4 yr)

> participated in the three randomly ordered exercises. A pronated,

closed grip

> was used for all exercises. The mean integrated EMG values from

three

> isometric maximal voluntary contractions were used to determine a

reference

> EMG (EMG(MVC))for each muscle. Normalized EMG values (NEMG) were

determined

> by EMG(int)/EMG(Mvc) and analyzed by one-factor repeated measures

ANOVA for

> each muscle (PM and T) during each phase (absorption and force).

>

> RESULTS: There was no significant difference between the

equivalently loaded,

> different boundary exercises (PU and BP). Statistical significance

was

> determined between the differently loaded, equivalent boundary

exercises (BP

> and BP-NL) as well as the differently loaded, different boundary

exercises

> (PU and BP-NL).

>

> CONCLUSIONS: Results from this study support the theory that

activities of

> similar biomechanical motions and mass of loading, regardless of

the boundary

> condition, have comparable EMG values of primary muscle groups. In

addition,

> this study suggests external load is more important than boundary

condition

> in describing human activity.

--------------