Biceps curl, eller???

[ptpoul]

Mell Siff ved ting..

Ud fra alle de spørgsmål om bænk og biceps burde denne post være en sticky..

God læsning :)

Is There A Biceps Curl?

The apparently simple biceps curl, although one of the trademarks of

bodybuilding, remains poorly understood by gymnasium users and scientists

alike. Even EMG (electromyographic) studies have proved notoriously

contradictory during attempts to ascertain exactly which arm muscles are

involved at a specific instant during elbow flexion.

Elbow flexion is produced by the cooperative action of the biceps brachii,

brachialis and brachioradialis. Of these, the biceps cross the shoulder and

the elbow joints, whereas the other two flexors act strictly on the elbow.

Thus, if strict arm flexion is to take place, there must be no movement about

the shoulder joint. This fact is well known to bodybuilders who execute the

curl with elbows dug into the sides of the trunk or with the back leaning

firmly against a wall.

Several basic factors profoundly effect which elbow flexors become involved

in any type of forearm curl:

- orientation of hand (pronated, supinated or neutral)

- the intensity of resistance to movement

- speed of movement

- degree of shoulder extension/flexion

- degree of shoulder abduction.

A detailed EMG study of elbow flexion performed with variations of these

factors was carried out by Basmajian (Muscles Alive, 1978). His time

analysis of activity revealed that there is a completely random sequence of

appearance and disappearance of activity in the different elbow flexors of

his subjects. In any sample of subjects, there appears to be no predictable

pattern among the muscles for activating, sustaining and terminating

flexion.

Moreover, muscles which display the greatest activity in individual subjects

only begin the movement first and end it last. He concluded that there is a

fine interplay between the biceps, brachialis and brachioradialis throughout

elbow flexion, so that it is inappropriate to identify a specific muscle as

playing a specific role at any given instant. Most remarkable was the wide

variation in the response produced by a given muscle. Although a general

trend may be described, the same type or sequence of activity rarely occurs

in different subjects.

The long head of the biceps (whose tendon passes through the shoulder joint

capsule) shows more activity than the short head in most subjects during slow

elbow flexion, during supination of the hand against resistance, and during

shoulder flexion. There is little difference in electrical activity between

the two heads of the biceps during isometric contraction or during eccentric

elbow extension. These observations are directly relevant to the bodybuilder

who wishes to exercise a specific head of the biceps more strongly.

Miwa and Matoba (quoted by Basmajian) found that, during slow elbow flexion,

biceps brachii is much more active electrically at certain angles of flexion.

Unlike the variation of isometric force with angle, the EMG reveals peak

activity at 160 degrees, almost nil at 90 degrees (surprisingly, where

isometric force is near a maximum), and strong activity at full flexion

(where isometric force is relatively low). Clearly, much still has to be

learned about the interaction between the nervous and muscular systems.

Biceps brachii is usually active during flexion of the supinated forearm for

all intensities of loading and during flexion of the semi-prone forearm

against resistance (as with 'hammer curls'). However, if the forearm is

prone (as with reverse grip curls), the biceps play a minimal role during

concentric and eccentric elbow flexion. This finding directly contradicts

the traditional belief among bodybuilders that the biceps continue to play a

major role during all forms of elbow flexion. It is brachialis which

displays this prominence, since it is active during fast and slow elbow

flexion with forearm prone, semi-prone or supinated at all intensities of

loading. It appears that brachialis contributes to all variations of elbow

flexion, since its line of pull does not change with pronation or supination.

This fact reveals that the term 'biceps curl' should be eliminated from the

exercise manuals and be replaced by the more accurate term 'arm curls' or

'elbow flexions'.

Brachioradialis does not play any significant role during any form of elbow

flexion without a weight, although it becomes much more strongly involved d

uring rapid flexion and extension with the forearm in all three positions of

rotation. This muscle, therefore, is seen to act as assistant mover when

rapid or strongly resisted flexion occurs.

All three elbow flexors contract strongly when a resistance is overcome

during flexion of the semi-prone forearm. Basmajian describes the semi-prone

orientation of the forearm as the natural position, the position of rest and

the position of greatest mechanical advantage for most functions of the upper

limb. In other words, the hammer curl, with palms facing the sides of the

body, rather than the supinated (palms up) curl, should be regarded as the

fundamental type of arm curl.

Another interesting finding is that the triceps - traditionally regarded as

only an extensor of the elbow - is strongly active during pulling movements

(such as seated rowing) with the elbow flexed. The biceps are powerfully

involved while the elbow is close to full extension, but the triceps

contribute as the angle of flexion increases, undoubtedly since the shoulder

is extended backwards, thereby making use of the long head of the triceps as

a shoulder extensor.

The apparently simple act of elbow flexion, often regarded as synonymous

with the so-called biceps curl, displays subtle nuances of functional

anatomy which have eluded much of the fitness community for many years. A

greater appreciation of the richness of all variations of elbow flexion would

contribute significantly to the implementation of more effective normal and

rehabilitative training.

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

Dr Mel C Siff

Denver, USA

http://groups.yahoo.com/group/Supertraining/

[Anders]

Nu er jeg ikke lige den skarpeste til engelsk, så er der ikke nogen der evt. gider at gi' et ultrakort resumé af teksten - på dansk!? Det ville bare være forrygende! :)

[Hr Henning]

ser også gerne at en oversætter?

[AGV]

the hammer curl, with palms facing the sides of the

body, rather than the supinated (palms up) curl, should be regarded as the

fundamental type of arm curl.

Det ku' godt være man skulle begynde at køre noget hammer curls :o

[overarmen2000]

Hvordan skal det tolkes er det ikke sådan hammer curls normalt bliver udført oder was.

[Flexipecs]

Meget sjov/interessant artikel ;)

For at give en kort opridsning, så drejer det sig om biceps curl - altså selve bevægelsen og hvilke muskler bevægelsen rent faktisk aktiverer, og hvordan/hvornår den bedst gør det.

Albueledet har de 3 muskler biceps brachii, brachialis og brachioradialis forbundet. Alle 3 muskler aktiveres ved en curl bevægelse; men undersøgelsen viser, at det er meget forskelligt hvornår og hvordan de aktiveres hver for sig og sammen.

Forskellene kan komme af:

Hændernes posotion, bevægelsens hastighed, hvor meget albue en foldet sammen (flexed) og fysisk modstand (vægt).

Fx. blev det påvist, at biceps brachii havde vidt forskellig aktivitetsniveau ifølge EMG målinger alt efter vinklen på armen (altså hvor sammenfoldet albuen var). Ved en 160 graders vinkel var der aller størst aktivitet, hvorimod der ved en 90 graders vinkel næsten ingen aktivitet var (hvilket man jo burde tro var anderledes ). Ligeledes var der stor aktivitet når albuen var helt 'foldet' sammen.

Biceps brachii er aktiv når der curles med håndfladerne opad eller med håndfladerne indad (hammer curl bevægelse); men der er næsten ingen biceps aktivitet når der curles med håndryggen opad (reverse curls) - her er det brachialis der tager over. Brachialis involveres faktisk ved alle typer curls og ved enhver hastighed og ved enhver modstand.

Brachioradialis derimod bliver kun aktiveret ved enten hurtige albue foldninger eller hvis der er tung fysisk modstand.

Til gengæld bruges alle 3 muskler hvis der bruges hammer curl bevægelsen med vægt/modstand.

[Mr.Freeze]

Mel Siff stiller spørgsmålet om der findes noget der hedder biceps curl. Fordi han mener det burde hedde arm curl istedet, da der er flere muskler der er involveret end bare biceps.

Han gennemgår de muskler der påvirker bøjning af armen og hvilke muskler der påvirkes alt efter hvordan håndfladen vender. Han konkluderer at hammer curl er burde være fundamentet for ens overarmstræning og at bodybuildere bør indse at de skal inkludere flere variationer i deres overarms træning end bare den traditionelle "biceps curl", da der er meget mere at hente.

Det er artiklen kogt ned til et par linier. I andre skal være velkomne til at tilføje.

Edit- Der var jeg vist lidt for langsom ;)

Edited August 26, 2004 by Mr.Freeze

[overarmen2000]

Ok så det mest effektive ville være forskellige hammer curl varianter og er der andre ting han ellers foreslår.

[chono]

Ville mene brachioradialis bliver aktiveret i højere grad ved alm dumbell curls, end hammer curls, da wrist er låst i hammer curl ??

"Seated Alternating Incline Dumbell Curl", is your friend ;-)

Edited September 2, 2004 by chono

[ptpoul]

Ville mene brachioradialis bliver aktiveret i højere grad ved alm dumbell curls, end hammer curls, da wrist er låst i hammer curl ??

Brachioradialis does not play any significant role during any form of elbow

flexion without a weight, although it becomes much more strongly involved d

uring rapid flexion and extension with the forearm in all three positions of

rotation. This muscle, therefore, is seen to act as assistant mover when

rapid or strongly resisted flexion occurs.

[wizz]

...

Edited December 4, 2011 by wizz

[kajakroer]

Her er en oversigt over MRI målinger af forskellige bicepsøvelser. MRI

Æhh - hvad er det nu lige en MRI-måling er...?

- Kajakroer

[ptpoul]

Magnetic Resonance Imaging.

Er så vidt jeg forstår baseret på blodgennemstrømningen i de pågældende muskler efter udført øvelse?

Dvs. de muskler der har arbejdet hårdere => højere blodgennemstrømning af blod efterfølgende => kan måles via magnetisk resonans billeder.

Tror jeg nok :)

[chono]

PtPoul: du skriver: Brachioradialis does not play any significant role during any form of elbow flexion without a weight, although it becomes much more strongly involved d

uring rapid flexion and extension with the forearm in all three positions of rotation.This muscle, therefore, is seen to act as assistant mover when

rapid or strongly resisted flexion occurs.

Din citering skriver : Brachioradialis does not play any significant role during any form of elbow flexion without a weight...men hvad med vægt på ?

For hvis du tager alm dumbell curls, bruger du jo brachioradialis til at holde håndledet låst..så det må da være indvolveret i øvelsen ?

Edited September 2, 2004 by chono

[Stryger2]

Her er en oversigt over MRI målinger af forskellige bicepsøvelser. MRI

Passer egentlig meget godt med mine egne erfaringer. Oversigten viser at stående bicepsøvelser ser ud til at være lidt mere effektive, og jeg har kun haft fremgang siden jeg droppede isolerede bicepsøvelser til fordel for tung stående curls.

[ptpoul]

Most remarkable was the wide

variation in the response produced by a given muscle. Although a general

trend may be described, the same type or sequence of activity rarely occurs

in different subjects.

In any sample of subjects, there appears to be no predictable

pattern among the muscles for activating, sustaining and terminating

flexion.

Dvs. der er stor variabilitet fra det ene menneske til det andet.

more strongly involved during rapid flexion and extension with the forearm in all three positions of rotation

Dvs. i alle tre positioner er brachiorradialis aktiv ved hurtige/kraftfulde bevægelser.

For hvis du tager alm dumbell curls, bruger du jo brachioradialis til at holde håndledet låst..så det må da være indvolveret i øvelsen ?

Det syntes du så.. Det kan være det er sådan for dig (læs citaterne om den store variabilitet). Men det er ikke noget der er fundet, i de undersøgelser der beskrives hér.

Det passer udemærket på en anden undersøgelse, jeg læste vedrørende regionær hypertrofi af triceps.

Dér var belastningen afgørende for, hvilken del af triceps der voksede mest.

Dette review viser med al tydelighed at gammeldags forestillinger om at håndposition/kropsstilling er den eneste faktor, der skal tages højde for, hvis en enkelt muskel i en muskelgruppe skal prioriteres frem for en anden ikke holder vand.

Faktorer så som tempo og load er meget vigtige.

Så at sige at dumbell curls involverer brachiorradialis i højere grad, er en stor oversimplificering.

Den almindelige antagelse er at brachiorradialis' funktion er albuefleksion og sekundært at trække hånden mod neutral (tommelen op efter) fra en henholdsvis proneret/supineret tilstand. Dette ser ud til at være en simplificering -eller måske decideret ukorrekt.

Ud fra disse resultater må det konkluderes at den er en accesorisk flexor der primært aktiveres ved høj spændinger/hurtige bevægelser.

Mvh Poul

Edited September 2, 2004 by ptpoul

[Guest Slettet bruger]

poul> træning af mine biceps foregår således:

4-5 sæt af smalt underhåndsgreb chins (med fokus på at trække med biceps...)

3-4 sæt af 8-10 semi-slow reps hammercurls...

- Hvordan ved jeg om dette er tilstrækkelig træning af biceps (med udgangspunkt i massetræning)?