dangerous exercises....
sorry,das ich schon wieder mel siff zitier,aber er trifft den punkt halt ziemlich oft
:
Behind Neck Presses and Dangerous Exercises:
Robert Pilger wrote:
Tudor Bompa for one as discused this exercise and stated that there is a
poor mechanical advantage of the shoulder joint. A few possible scenarios
could evolve, rotator cuff can be jammed under the acromion,(causing
impigement) and when performing the press the joint can be moved out of it's
optimal instianious axis of rotation, leading to instability in the joint.
Paul Chek has also claimed it puts undue stress on the neck and upper back,
while people flex their head forward performing the exercise.
One can create similar apparently horrifying theoretical scenarios for
almost any exercise. If any biomechanists described in kinesiological
terms how prone one is to serious injury in running, you would read that the
knee is the largest and inherently least stable major joint in the body, that
the menisci are likely to be "nipped" by the rapidly moving femur and tibia,
that the cruciate ligaments are being overstressed, that numerous actions in
the ankle and foot are causing potentially extremely hazardous manoeuvres as
they tilt, rock, twist and deform to accommodate the constant absorption and
generation of force, etc, etc. In no time, all the fitness and medical
associations on this planet might be militating against running!
Possibly this may all sound exaggerated to you, but few fitness professionals
and
sports coaches ever are exposed to that level of critical analysis of common
daily movements simply because they are regarded as perfectly natural and
generally safe. However, clinical records show exactly the opposite, namely
that the most common injuries are associated with the most common daily
activities like running, swerving, turning, throwing, jumping, kicking and
striking - and that it is not all these "forbidden exercises" that are
keeping orthopaedic surgeons and therapists in business.
Thus, a major part of the problem is that only exercises that a priori
(decided in advance) are considered to be dangerous are analysed in negative
terms, while other exercises that are already perceived to be safe usually
are discussed only in "normal", "neutral" or "safe" terms. In other words,
there is a very strong bias or prejudice well in place before anyone ever
undertakes any study of human movement and it is this subjective, often
emotive framework which can seriously distort what we learn in applied sports
science.
Interestingly, mild flexion of the head forward, coupled with less marked
external rotation of the upper arms, is something which tends to make press
behind the neck less risky.
Incidentally, Chek has not produced any research or clinical evidence of this
"undue" stress, especially since the forces, torques and movement
trajectories involved with behind the neck presses depends on several
important variables, including hand spacing, neck disposition, degree of
external rotation of the humerus, starting position, use of any ballistic
motion, the use of any prestretch and the relative use of concentric,
eccentric and isometric action. His claims are based solely upon opinion.
I myself, along with my clients never perform this exercise. Myself
competing in boxing for over twelve years, never experianced any rotator cuff
strain or injury, and at a young age was taught never to predispose your
shoulders to any undue stress. I did try the exercise once or twice however,
and felt very uncomfortable.
Note that some common exercises used very safely by weightlifters are
behind the neck push jerk, the behind the neck jerk and the snatch grip press
behind the neck drop into a full squat snatch. One of the most important
safety issues is not to allow the load to drop rapidly under eccentric
conditions behind the head or to allow the upper arms to be forced strongly
and passively into external rotation.
A common mistake made by average trainees is that they rest the bar on the
shoulders before pressing (instead of push pressing it up or taking it from a
fully locked arm position), thereby abolishing any protective prestretch and
they often lean forwards or round the spine before starting the action. Of
course, there are even some misguided individuals who believe that it is
safer to "draw in the abs" and to do seated versions of this exercise,
forgetting that if you are standing, you are able to absorb a great deal of
the eccentric shock as the weight descends onto your shoulders. There are
several other safety precautions, but these should suffice for now.
cheers,klaus
