PP 87 : CONTRAINDICATED EXERCISE PARADOX



The risks of so-called contraindicated exercises may be exaggerated or
misleading when viewed in the light of biological adaptation.

Sports and medical science have been warning  us for many decades against the
dangers of certain exercises because it is maintained that these can cause
structural damage.  Thus, dire warnings about spinal flexion, deep squatting,
ballistic stretching, spinal hyperextension and numerous other actions have
been proclaimed throughout the fitness and health professions.

In the case of inanimate mechanical structures, predictions concerning the
effects of certain types of static or dynamic loading can be made with a
fairly high degree of accuracy, but in the case of the human body, the fact
that the body is self-repairing and self-adapting confounds the issue.  Even
in inanimate systems the type of loading, tempering or  curing can produce
specific advantageous effects in the given material. 

In other words, loading can produce beneficial or detrimental effects.  In
engineering, this is used to great advantage in producing materials or
structures that are far better equipped to handle higher levels of stress. 
We might be tempted to say that repetitive flexion of a given metal rod is
dangerous and should be avoided at all costs - but that same rod, as part of
a structure, may be called upon to cope with that very type of long-term
repeated flexion for many decades or centuries.

Certainly any system can be forced to deform or fail completely, depending on
the precise manner of loading, but 'conditioning' and design of the structure
can ensure a prolonged and failure-free lifespan.  A key issue is designing
the system with a certain 'safety factor' to ensure that the system will not
fail under certain multiples of the worst anticipated conditions. An
engineering structure is invariably 'overdesigned' to cope with any
unforeseen levels or directions of loading.  This means that a certain degree
of 'dangerous' loading is catered for and this constitutes good engineering
design.

In the case of the human body, the principle of gradual progressive overload
serves as a type of loading procedure that  allows the body to adapt to
gradually increasing loads.  This is one of the fundamental principles of all
training adaptation.

Thus, if the limits of loading are not exceeded in any inanimate or animate
system, then damage will not occur.  This must then imply that it is
relatively safe to allow the body to be used imprecisely or  inefficiently,
provided that certain structural limits are not exceeded.  After all, we know
that a certain degree of adaptation will always strengthen the most stressed
parts of the body, provided that their mechanical limits are not exceeded.

We also know from the principle of gradual progressive overload that
thisrepeated activity will make these stressed structures stronger and
stronger,so that they will be better equipped next time to handle poor
technique or deviations from the recommended 'norm'.

In other words, it would seem that the body will adapt to certain levels of
'harmful' exercising, provided that this is not imposed near the mechanical
limits of the given soft tissues.  If this is done progressively in a
controlled manner, then the body should become capable of handling all of the
so-called dangerous activity.Does this not sound reasonable and logical?

Does this not imply that the neurosis about exercise safety may be misleading
and inaccurate?  After all, the body adapts to all types so-called neutral,
natural or safe norms? 

Worded in another way, we might state that perfect training produces
maladaption, while integrated, well-sequenced phases of perfection and
imperfection produce superior functional adaptation.

Comment on the apparent paradoxes  of 'safe' or 'correct' exercise, as
outlined above, drawing on appropriate references or your own expertise.
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PP 88 : MUSCLE FIBRE PARADOX



Attempts to relate sporting performance to muscle fibre types may be
premature and misleading.

A great deal of literature has appeared on the relationship between types of
muscle fibre and types of physical activity.  Generally, it has been shown 
that weightlifters, track-and-field athletes and other explosive type
athletes have a high percentage of fast twitch muscle fibres in the
propulsive muscles, based on studies of characteristic muscle groups such as
vastus medialis and gastrocnemius.  Conversely, distance runners and other
cardiovascular endurance athletes have been shown to have a large percentage
of slow twitch fibres in the same muscle groups.

Consequently, it has been deduced that genetics determine what type of
athlete one is likely to become.  Those accepting that there may also be a
training, as well as a genetic determinant of sporting excellence, have
concluded that training must be suited precisely to reflect the dominant
muscle fibre types of the individual or to attempt to cause adaptive changes
in those whose muscle fibre profiles are unsuitable for a given sport. 

Thus, we see that Olympic-style weight training is used to stimulate fast
twitch fibre changes, if these indeed occur to a significant extent in either
the actin-myosin structure or in the enzyme environment of the given muscle
fibres.

These deductions and recommendations assume, of course, that histological
analysis of muscle correlates accurately with functional muscle performance. 
In other words, if biochemical/histological tests show that the fibres have a
certain colour, blood supply, enzyme profile, metabolic structure and so
forth, then they must be able to contract, relax or hold a contraction for a
certain time and at a certain intensity. 

This suggests that all FT fibres (of a given type - FTa or FTb fibres etc) 
display the same force-time curve and contract rapidly at the same velocity. 
Similarly, all ST fibres or any other types of fibre class, for that matter,
contract at a given rate. 

However, scientists know that all structural and functional measurements of
events generally display a characteristic bell-shaped or Gaussian
distribution - and muscle fibre types are no exception.

In other words, some FT fibres will be contracting at a very rapid rate,
while others will be contracting at a much slower rate.  Similarly, some ST
fibres will contract at fairly high rates, while others will be thoroughly
pedestrian.  This leads us to wonder if some FT fibres may be contracting as
slowly as the faster contracting ST fibres.  If we take into account the
findings of some scientists who show that, instead of there being a sequence
of a few groups of muscle fibre types, there actually is a smooth continuum
of muscle fibre types, constantly in flux at any given instant.

Does this not then suggest that current attempts to classify athletes largely
in terms of muscle fibre types and to design training on this basis may be
seriously misleading?  Are we justified in correlating speed, intensity or
fatiguability of muscles solely on the basis of non-functional
biochemical/histological tests?  Is it accurate to state that a chemically
classified muscle sample is indeed functionally very swift, while another is
positively geriatric in performance?  Attempts to relate muscle fibre typing
to certain types of motor ability may be misleading and inaccurate (unless
measured by means of the less accurate neurological method of
electrostimulation-elicited twitches and EMG asessment of the resulting
twitches).

Comment on the above discussion and discuss its validity in terms of suitable
references.
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PP 89 : ERGONOMICS PARADOX



The emphasis on the design of ergonomically correct seating and sleeping
surfaces may be misleading,  unwarranted and over-commercialised in many
cases.

The value of the 'correct' type of seating or bed is frequently
promoted as the solution to many spinal problems.  Thus, we are
informed that it is vital to have a chair of the 'right' height and
contours to maintain neutral spinal curvatures, else we are going to
precipitate back pain and disability.  Similarly, we have to use a
bed which adapts precisely to the spinal curvatures, giving just the
'right' degree of softness and firmness.

There are many laboratories, most of them funded or owned by
manufacturers of office or home furniture, which produce impressive
biomechanical studies which purport to have identified the optimal
sitting and sleeping positions.  They have relied on video filming to
examine postural patterns, pressure sensors in chairs and bed surfaces
to identify areas of stress concentration, mathematical models of
loading at different levels of the spine, EMGs to examine which
muscles are active during sitting or lying, and other ingenious methods
for understanding what happens to the spine with and without the use
of various ergonomically designed devices or surfaces.

Consequently, executives have been convinced by this research to
purchase extremely expensive 'ergonomically correct' chairs or cars
which have similarly impressive seats.  At the same time other companies
have convinced them that their persistent low grade spinal discomfort or
semi-permanent disability is due to their non-ergonomic beds or mattresses.
So, at home they are now using highly expensive sleeping systems.

Are we justified in placing such emphasis on so-called ergonomic
design to solve many of the problems of human life or are the results
of research being skewed by the influence of commercial funding?  We
have to enquire if some measure of unwarranted extrapolation is being
made from various research populations. 

We have to ask if the EMG studies are measuring functional or spurious muscle
tension, we have to ask if any meaningful estimates of ligamentous fatigue
have been made, we have to ask if the spinal problems are being caused by
poor
motor skill in general and we have to ask if the studies have attempted to
take into account the possible effects of other daily activities (other than
sitting and lying) on the back.

Possibly of greater concern is to wonder how measurements taken of a
person sitting or lying in one fixed position correlate with postural
situations in the real world in which people are constantly shifting
around on their seats and in their beds.  While driving a vehicle or
piloting an aircraft (or being a passenger) may compel one to sit for
fairly long periods in one position with the back pressing against
the back rest, in the real world, one constantly moves around,
crosses the legs, uncrosses them , leans forward, rests on the
elbows, raises feet on the desk and so forth.  In other words, the
occupant of any seat spends a considerable amount of time NOT relying
on support from the ergonomically designed back or correctly angled seat.

Similarly, studies of pressure distribution and number of nocturnal
movements in bed tend to focus on a single static position at a time.
In reality, the body constantly moves around from one position to
another all night.  Indeed, this is a characteristic of normal sleep, as
numerous sleep laboratory studies have shown.  Promoters of
ergonomically designed beds promote their beds or other devices by
stating that pressure concentrations are avoided and there are fewer
nocturnal gyrations when their products are used. 

On the contrary, anyone working clinically knows that patient failure to
move around regularly can traumatise many of the soft tisssues of the
body.  In the case of the spinally disabled, failure to shift
regularly can produce life-threatening pressure sores.  Are
researchers then justified in correlating improved sleep with fewer
nocturnal gyrations?  Does the body not compensate quite adequately
on any firm surface to provide sufficient variation to ensure that
the spine is not insulted by inappropriate patterns, durations and
directions of motion or stabilisation?

Can one state that the most costly ergonomically 'correct' chair
offers safer seating than any fairly comfortable chair without a
back?  This strict, carefully balanced posture was characteristic of
many societies and it compelled one not to slouch or simultaneously
hyperflex and rotate the lumbar spine, as invariably happens when we
sit for hours in our lounges watching TV or entertaining our friends.

While we are on this topic, why have we yet to discover an
ergonominally 'correct' sofa or settee?  After all, this informal
setting is where we spend most of our inappropriate sitting and lying time.

Are we being misled by furniture manufacturers about the apparent
benefits of costly ergonomically 'ideal' seats and beds, when  a
modicum of more formal postural education and strength training might offer
far greater benefits?  Have there been well-controlled studies that
show that there is a significantly higher rate of spinal pain and
disability among populations which never use ergonomically 'ideal'
furniture?

In this context, we need to look not simply at our First
World populations using any random type of furniture, but also Third
World populations who sit and sleep on mats directly on the floor or
on simple thong furniure, straw chairs or hammocks.  Are we being
influenced more by commerce than science?

Comment on this entire issue of ergonomic correctness, quoting any
references which you may consider appropriate to support your point
of view.
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PP90:  ROTATOR CUFF PARADOX



The current emphasis on special isolationist exercises for rotator cuff
rehabilitation and training may be inefficient and functionally illogical.

ARGUMENTATION

It is very common to attend conferences and read scientific articles on
rehabilitation and conditioning of the rotator cuff muscles by means of
highly specific movements intended to isolate the actions of the four major
rotator cuff muscles (supraspinatus, infraspinatus, teres minor and
subscapularis).

Virtually everyone who deals with rotator cuff strengthening has been exposed
to movements which fixate the elbow pivot at right angles to the arm (upper
arm) in some specific position and require the forearm to be abducted or
adducted in a manner reminescent of a traffic officer directing traffic or a
'mac flasher' opening his raincoat to expose himself to anyone who meets his
perverted eye. 

There are several variations to this muscle isolation theme, with the client
standing, sitting, lying prone or supine on a plinth, pushing or pulling
against some pulley system, manoeuvering a light dumbbell in a set arc about
the elbow pivot, and so forth.  The general idea and effects are the same,
namely the use of a movement pattern intended to isolate one or two of the
rotator cuff muscles and to suppress involvement of the others. 

The philosophy seems to be that if muscle testing reveals that a given
rotator cuff muscle is injured or relatively weak, then that muscle alone
must be isolated and exercised until it is strengthened up to its desirable
level (whatever that might be).

Yet, amidst all these isolationist ideas, every physical therapist learns the
merits of PNF (proprioceptive neuromuscular facilitation) patterns which
require the use of specific patterns (not just isolations) to recruit all of
the muscles and phases of muscle actionassociated with a given joint.  Why
then do so many therapists and trainers choose to ignore this
well-established body of knowledge, abandon the carefully-tested patterns of
PNF and focus on non-spiral, non-diagonal, non-functional movements in highly
restricted planes of action.

It is sometimes argued that injury or weakness prevents a person from being
guided through a full PNF pattern, but the procedures of PNF permit any
movement pattern to be initiated, terminated and resisted according to
individualised needs.  In other words, it appears as if the currently popular
elbow-fixating, muscle isolation rotator cuff exercises contradict the tenets
of well-tried PNF rehabilitation and conditioning.

This isolationist approach would not appear to develop the types of muscle
strength or muscle endurance pattern encountered in normal functional
activities such as throwing, hitting, catching and lifting.  Moreover, 
rehabilitation also has to program the CNS to enable the muscles to act in
symphony in a wide variety of motor acts at different rates and in patterns
requiring the production of specific levels of strength at different joint
angles - something that isolationist training does not offer in the patterns
required.

Of course, one may argue that isolationist training applies only to the acute
stages of rehabilitation and that it must be followed by the necessary
functional sporting activities when the supposed agonist-agonist and
intra-rotator cuff muscle strengths have been re-established.  This comment
would appear to be fairly logical, but then it has to be asked why one would
not employ more functionally relevant PNF patterns or even special patterns
drawn from the same sporting actions during which the injury occurred or in
which some 'imbalance' was noted. 

Why should it be deemed necessary to expend valuable time on isolationist
movements when the time could be spent more productively on more functional
and biomechanically more useful patterns of movement?

It also has to be noted that actions of the shoulder joint involve some
rotator cuff muscles, as well as others (e.g.  lateral rotation implicates
teres minor, infraspinatus and the posterior deltoid; shoulder extension
involve infraspinatus and teres minor as well as lats, teres major, posterior
deltoid and the long head of the triceps). 

The graduated cooperation between the various shoulder muscles also has
profound implications for the isolationist approach.  For example,
supraspinatus and the deltoid group act in carefully graduated harmony to
offer smooth abduction of the arm.  Here, the supraspinatus acts more
strongly in the early phases of lateral arm raising, with the deltoids
becoming more strongly involved as the degree of abduction increases.  At the
same time, the range of movement depends intimately on concurrent scapular
rotation (to prevent the so-called impingement syndrome).  It would certainly
seem that the use of isolationist rotator cuff movements seriously neglects
the early training of this group of shoulder movements.

Rehabilitation also does not concern only the injured muscle, but its role in
interacting with other muscles, so that the isolationist approach would
appear to disrupt several interactive motor processes which manage the wide
variety of stabilising and mobilising functions of the shoulder joint (and,
of course, its reliance on synchronised interaction with the muscles of the
scapula).

In addition, use of muscle 'isolation' movements may impose unusual stresses
on muscles and other soft tissues that are not usually encountered during
actual sporting movements, just as is being shown by research into the
isolation-related stresses exerted on knee structures by leg extension
machines and isokinetic rehabilitation devices.

Does this imply that the use of popular isolationist rotator cuff
rehabilitation and training exercises should be abandoned in favour of the
clinical PNF and sporting patterns of shoulder action which relate more
closely to natural functional movements in daily and sporting life?

Offer your comments on this issue, by quoting any references which you
consider to be appropriate or by drawing on your own experience.
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