I must admit, that this site is one of the most complete one
I've ever seen. But some of the exercises depicted have serious
flaws to them. Take for example the stiff-legged deadlift. In
the clip, the individual loses his lordosis during the lowering
of the bar. This will only ensure ligaments being stretched and
create greater instability in the lumbar region. Same applies
for the Seated Row. Leaning over while returning puts the stress
solely on the ligaments of the spine since the musculature is
relaxed. Also, the incline sit-up can also create some pressure
unto the lumbars from the Psoas muscle. Having your feet anchored
actives the movement from the origin rather than the insertion.
One last suggestion, would be the exercises for low back and
recuperation. Most low back problem are caused from lack of flexibility/muscular
lateral imbalance. Working the core stability and flexibility
rather than weight training would be most beneficial for those
people. I'm sure you can relate to these issues and hopefully
make corrections. After all, its for everyone's good.
Concerned visitor (Bsc. Kin., PFLC)
Concerned visitor,
Muscular imbalance and inflexibilities may be attributed to
injury, but the causes of lower back injury are poorly understood
(Nelson 1993). Although the views you express are popular, I
used to hold similar beliefs, other authorities and I disagree
with this oversimplified theory. These generalizations
are in contrast certain peer refereed journals, academic texts,
empirical evidence, and my professional experiences.
Common Beliefs
Commonly held beliefs on the causes of injury are often not
supported by scientific studies. For example, a past colleague
performed an exhaustive review of the scientific literature on
the problems associated with hyperextension
of the lumbar spine during the Powerlifting-style
bench press. He found no studies remotely demonstrating problems
with this posture despite commonly held beliefs in the exercise
community.
Even the idea flexibilty exercise decreasing injury has been
questioned by recent studies and meta-analyses. See Stretching
and Flexibility. Certainly certain individuals may need to
improve their flexibility in particular joints, yet others may
be found to have too great of flexibility through certain joint
articulations. To suggest flexibility training should be prescribed
over strength training is a gross overgeneralization. Strength
training has been shown to be very benifitial in physical therapy
and injury reduction. Just look up the studies listed below (see
references) and the many others in listed on PubMed.
It is interesting that many orthopedic surgeons denounce certain
commonly performed exercises. For example, some physicians condemn
squats
citing how destructive they are to the knees despite scientific
studies and millions of personal experiences to the contrary.
It is undeniable that people can hurt themselves on any exercise,
more some than others, but the issue is much more complex than
the exercise itself.
Poor form, faulty technique (including altered form due to
fatigue), bad program design, insufficient warmup, overtraining,
lack of progression (eg: exercise selection, resistance, training
volume), and certainly, particular biomechanical deficiencies
predisposing individuals to injury are all factors that lead
to injury. Also see Causes
of Injury.
Incline Situp
During the first portion of the sit up, the abdominal muscles
flex the spine. The hip flexor muscles flex the hip to complete
the movement. If the abdominal muscles are not strong enough
to counter the Psoas'
pull on the spine, the lumbar vertebrae can be forced into hyperextension.
This can occur during other hip
flexor movements as well.
In the book "Strength
Training for Young Athletes" by Kraemer and Fleck, the
cover states "Includes over 100 safe exercises for 18 muscle
groups and 16 sports. They include two sit up exercises with
the feet anchored
- Page 105: Bent-Leg Sit-up
- Page 106: Bent-Leg Sit-up with a Twist (on incline)
Steven
J. Fleck, PhD and William
J. Kraemer, PhD are probably the most well respected scientists
studying resistive training. Fleck and Kreamer have dedicated
their careers in investigating researching, and writing both
scientific and main stream publications on weight training.
Kreighbaum (1996) states: "The physical condition of
the performer dictates how safe and effective these exercises
will be in the strengthening the abdominal"
For those with no history of lower back pain during hip flexion,
situps
or leg-hip
raises can be considered so the abdominal
and hip flexors
can be exercised in a single exercise. A determination should
be made if the client has adequate abdominal strength to counter
the psoas' pull. Like the lower back integrity previously discussed,
this biomechanical deficiency can be easily corrected (see links
immediately below). Crunches, or half sit ups can be prescribed
for the first months before the introduction of hip flexor movements.
Incidentally, the bend of the hip severally diminishes Psoas'
mechanical efficiency and consequently its pull on the lumbar
spine. See tension
potential. Kreighbaum (1996) adds: "For a performer
with weak abdominal, the hip-flexed position is the best".
Also see
Flexible hip flexors and strong abdominal muscles are particular
important before performing the Decline
Situp, Roman
Chair Situp, Leg
Raises and Hip
Raises since the hip becomes fully extended.
As for having your feet anchored effecting movement from the
origin rather than the insertion, this essentially does not effect
its activation. The muscle contracts through out itself despite
the end that moves (origin or insertion). Are the forces through
the Latissimus Dorsi
some how different in pullup
as compared to the pulldown?
Your old physics or biomechanics book will clarify the forces
are indistinguishable. Incidentally, the crest of the pubis is
often referred to as the origin of the Rectus Abdominis, anyway.
Obviously, man made classification systems do not perfectly fit
all constructs; these semantics merely propitiate rhetorical
arguments.
In a horizontal position, the anchoring of the feet will allow
you to stabilize the lower body without extending the legs to
counter the leverage and momentive forces of the upper body during
its extended leverage in the lower position. Remember when the
hips are extended the Psoas is activated more. In an incline
motion, the anchoring of the feet prevents you from sliding back,
or falling on your head.
If a client has such weak abdominal that their psoas is pulling
on the back, corrective exercise should be performed months before
they start on intense hip flexor exercises. To say sit ups are
bad, or any other exercise is bad is a gross over-generalization.
Cable Row
The Cable Seated Row is an excellent movement to condition
both the upper and lower back. Even Arnold Schwarzenegger as
well as countless other weight trainers perform their cable rows
with an articulating spine.
The body adapts to specific stresses placed on the body as
long as certain principles are followed. Both the muscles and
joint structures can adapt to progressive stresses. Even the
elastic limit of a tendon or ligament can be enhanced by exercise
and training and can be reduced by aging and inactivity (Tendon and ligament
adaptation). Ligaments are not inert.
During the seated row with spinal articulation you say, "Leaning
over while returning puts the stress solely on the ligaments
of the spine since the musculature is relaxed." In order
relax the muscles of the lower back, the exerciser would have
to set down the resistance weight and pause. Even if the exerciser
deliberately relaxed the musculature with the spine completely
flexed, the stretch in the lower back muscles would activate
the muscle spindles, or stretch receptors, maintaining an involuntary
contraction for several seconds. As with any exercise, moving
through the full
range of a joint's motion is recommended, yet not beyond.
Ironically, splinting the lower back during all movements
can lead to the degeneration of the joint structures of the spine
(Nelson 1993, 1995). Including an exercise such as the Cable
Seated Row that involves actual (dynamic) movement of joint structures
and accompanying muscles are important for lower back integrity.
As the saying goes "Use it or lose it". The Cable Seated
Row with articulating spine, the Cable
One Arm Twisting Row, as well as the Straight Leg Deadlift
(below) offer more natural forces
to entire kinetic chain as compared to Lever
Back Extension and can be implemented progressively for those
requiring high degrees of functionality such as certain athletes
and manual laborers. Also see Low
Back Debate.
The Cable
Straight Back Seated Row has been included for those who
desire less lower back involvement during this movement.
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