Think back, way back before the words fitness or strength training
were even part of your vocabulary. Can you recall the first muscle you
ever learned? Chances are it was the biceps. Long considered by the
general public to be the hallmark of weight lifting, strength, and,
should I dare say it even masculinity. The exercise traditionally
regarded as the key to biceps size was bicep curls. This will be the
focus of our bio mechanical analysis this month.
The biceps is situated on the front of the upper arm and actually has
two muscle bellies lying side by side, thus the name. Although the
muscle bellies attach at two different points on the shoulder blade,
they are joined at the distal ends by a common tendon of insertion. This
tendon weaves between the two bones of the forearm and attaches on the
back of the radius (outer of the two).
The biceps is one of three muscles responsible for flexing (bending)
the elbow against resistance. It is impossible to totally “isolate” the
biceps from the other two elbow flexors, but it is believed that the
biceps can be “emphasized” by maintaining a supinated grip (palm up)
during resisted elbow flexion or “curling” exercises. (Although they are
working considerably during biceps movements, you may want to spend
some time emphasizing these other elbow flexors as well, as part of your
overall arm routine.)
When performing the barbell curl the first concern is to determine the grip width on the bar. Traditionally we are taught to use a “shoulder width grip”. Now, if you’ve ever attempted this on a regular basis and with considerable weight, you may have detected a sensation that, for lack of better terms, I describe as a “shin-splint” type pain deep within in the wrist or forearms. This is due to the fact that a shoulder width grip on a straight bar violates a key aspect of the skeletal anatomy…the carrying angle.
If you stand in front of a mirror with your arms at your sides and
fully supinate (palms forward) you will notice that your hands do not
hang at shoulder width. This lateral angle that appears at the elbow
(outward bend of the forearm) is the carrying angle. To grasp a straight
bar without recognizing and allowing for your individual carrying angle
is a true violation of joint limits and function. Allowing for the
carrying angle usually results in a grip that is only an inch or two
wider than shoulder width. If you look in the mirror and it appears that
your hands are eight inches wider than your shoulders, you may need to
check the position of your upper arm. Did you turn your entire arm
outward instead of just supinating (turning the palm)? If you’re looking
at the inside of your upper arm and elbow in the mirror, then you
probably moved more than just your hand/forearm.
Once you’ve got the bar in hand, the key is to define (and practice)
the correct path of motion. Traditional instructions only make reference
to the motion of the bar. “Curl the bar up to your chin and back down.”
This overly simplistic, and actually misdirected teaching, leads to the
two major mistakes that ultimately defeat biceps lovers everywhere.
1) Shoulder extension (elbow appears to move backwards) to help initiate the movement, and 2) Shoulder flexion (elbow appears to move forward) to help finish the movement. The result…less biceps involvement and more shoulder work.
Now, let’s back up for a minute and examine this in common terms.
By only being concerned with the fact that the bar is traveling up
and down you may miss the most important aspect of the entire exercise –
which joints we’re moving.
Try this little experiment…
Stand with you side to a mirror and observe closely while slowly
curling a light weight. Does your elbow/upper arm drift backward as you
begin the curl? That’s really a shoulder joint motion called extension,
and thanks to the posterior deltoid, you really haven’t used much biceps
Now, as you continue, you’ll probably bring your entire arm
forward…so far forward that your elbow/upper arm are now in front of
your torso. As you finish the motion you’ll notice the elbow joint is
directly beneath the bar with your forearm vertical. At this point the
anterior deltoid is doing all the work because the weight is balanced
over the elbow, therefore elbow joint muscles are not required. Oh sure,
you can tighten them and really feel the squeeze, but there is
virtually no load on them…and what was the point of the biceps exercise
anyway? I thought it was to load/resist the biceps. If the goal was just
to tighten without resistance, we didn’t need the weight.
Finally, as you lower the weight, does your elbow/upper arm just travel back behind your body again with very little actual change in the angle between your forearm and upper arm. And even though the weight is all the way down to your legs, is your elbow still bent and positioned behind your torso?
If any of the above was true, then it’s time to re-examine the
mechanics and start really working the biceps. The key to the correct
motion is to first identify the parts that should not move! You see, the
goal is to have the biceps/elbow flexors control the weight, therefore,
elbow motion is all that is desired. The shoulder joint should be
static. Therefore your upper arm will not travel backward or forward at
any point during the exercise. From the side you should detect an arc of
travel of the bar as it moves around the axis at the elbow. When
performed correctly, the bar is actually moving “forward,” then “up,”
and then inward” in an arc from the bottom to the top of the motion, and
the reverse on the return.
Any exercise which emphasizes the biceps will aid in developing big
guns if it is performed correctly. Alternate between using the straight
barbell, EZ curl bar and dumbbells, your biceps don’t know the
difference. Each bicep curls exercise will work the muscles in a
different way, which is extremely important for mass development.