Dr Mel Siff Blog

<< In keeping with this discussion I recently found an excellent literature
review-
“Myths and Truths of Stretching” at the following website:
www.physsportsmed.com

It discussed some interesting principles such as desensitisation to stretch
rather the muscle spindle lengthening, which make one think about our
treatments and advices in the past. >>

*** Several of us have been questioning the necessity for the use of
dedicated “stretching” and “warming up” sessions for many years, so it is
good to see a review of this stature examining these issues in depth (see
Siff MC “Facts and Fallacies of Fitness” 2000). I also like to point out
that stretching exercise (which are meant to deform tissues) are not
necessarily the same as flexibility exercises (which are meant to increase
range of movement).

There are several interesting issues in Shrier’s article on stretching facts
and myths (THE PHYSICIAN & SPORTSMEDICINE – Vol 28 – No. 8 – Aug 2000), such
as this one:

< With respect to alleviating the pain associated with stiffness, the weight
of the evidence suggests that the decrease in stiffness is not as important
as the increase in “stretch tolerance”. Briefly, an increase in stretch
tolerance means that patients feel less pain for the same force applied to
the muscle. The result is increased range of motion, even though true
stiffness does not change. This could occur through increased tissue strength
or analgesia; however, increased stretch tolerance that occurs immediately
after stretching must be caused by an analgesic effect because tissue
strength does not increase during 2 minutes of stretching. Unfortunately,
evidence of a possible analgesic effect is recent, and the underlying
mechanism is unknown. After weeks of stretching, increases in stretch
tolerance could theoretically occur because stretch-induced hypertrophy may
increase tissue strength , and/or an analgesia effect may be present. >

***The use of the term “analgesic” may not be entirely appropriate. While
there may be an as yet identified analgesic effect associated with intense
stretching, this may be greatly overshadowed by an accommodation effect which
changes the Rating of Perceived Effort (or pain) with regular imposition of
progressively increased stretching loads. This happens with all lifting -
the load progressively feels lighter and the lifter then can execute more reps
or a heavier 1 rep max.

This is not necessarily the same as the so-called disinhibition effect which
is an objective altering of nervous processes in the body – it is an effect
that is more subjectively psychological in origin (even though it also
obviously involves neural processes).

Despite the very useful and interesting nature of this review, the reference
list was disappointingly small and it made no use of some really relevant
work by Russian scientists such as Iashvili (see Ch 3 of Siff & Verkhoshansky
“Supertraining” 1999).

At least, the high profile given to this article will tend to make the
fitness pros and sports coaches start wondering a lot more about all those
traditional ideas about stretching and warming up.

Dr Mel C Siff

Dr Mel Siff in his usual style, addresses a number of myths about stretching in this great post from the Supertrainig Mailing List

<< In keeping with this discussion I recently found an excellent literature
review-
“Myths and Truths of Stretching” at the following website:
www.physsportsmed.com

It discussed some interesting principles such as desensitisation to stretch
rather the muscle spindle lengthening, which make one think about our
treatments and advices in the past. >>

*** Several of us have been questioning the necessity for the use of
dedicated “stretching” and “warming up” sessions for many years, so it is
good to see a review of this stature examining these issues in depth (see
Siff MC “Facts and Fallacies of Fitness” 2000). I also like to point out
that stretching exercise (which are meant to deform tissues) are not
necessarily the same as flexibility exercises (which are meant to increase
range of movement).

There are several interesting issues in Shrier’s article on stretching facts
and myths (THE PHYSICIAN & SPORTSMEDICINE – Vol 28 – No. 8 – Aug 2000), such
as this one:

< With respect to alleviating the pain associated with stiffness, the weight
of the evidence suggests that the decrease in stiffness is not as important
as the increase in “stretch tolerance”. Briefly, an increase in stretch
tolerance means that patients feel less pain for the same force applied to
the muscle. The result is increased range of motion, even though true
stiffness does not change. This could occur through increased tissue strength
or analgesia; however, increased stretch tolerance that occurs immediately
after stretching must be caused by an analgesic effect because tissue
strength does not increase during 2 minutes of stretching. Unfortunately,
evidence of a possible analgesic effect is recent, and the underlying
mechanism is unknown. After weeks of stretching, increases in stretch
tolerance could theoretically occur because stretch-induced hypertrophy may
increase tissue strength , and/or an analgesia effect may be present. >

***The use of the term “analgesic” may not be entirely appropriate. While
there may be an as yet identified analgesic effect associated with intense
stretching, this may be greatly overshadowed by an accommodation effect which
changes the Rating of Perceived Effort (or pain) with regular imposition of
progressively increased stretching loads. This happens with all lifting -
the load progressively feels lighter and the lifter then can execute more reps
or a heavier 1 rep max.

This is not necessarily the same as the so-called disinhibition effect which
is an objective altering of nervous processes in the body – it is an effect
that is more subjectively psychological in origin (even though it also
obviously involves neural processes).

Despite the very useful and interesting nature of this review, the reference
list was disappointingly small and it made no use of some really relevant
work by Russian scientists such as Iashvili (see Ch 3 of Siff & Verkhoshansky
“Supertraining” 1999).

At least, the high profile given to this article will tend to make the
fitness pros and sports coaches start wondering a lot more about all those
traditional ideas about stretching and warming up.

Dr Mel Siff

Miyamoto K et al Effects of abdominal belts on intra-abdominal pressure,
intra-muscular pressure in the erector spinae muscles and myoelectrical
activities of trunk muscles. Clin Biomech 1999 Feb; 14 (2):79-87

OBJECTIVE: To evaluate the effects of abdominal belts on lifting performance,
muscle activation, intraabdominal pressure and intra-muscular pressure of the
erector spinae muscles.
DESIGN: Simultaneous measurement of intra-abdominal pressure, intra-muscular
pressure of the erector spinae muscles was performed during the Valsalva
maneuver and some isometric lift exertions.
BACKGROUND: While several hypotheses have been suggested regarding the
biomechanics of belts and performance has been found to increase when lifting
with belts, very little is known about the modulating effects on trunk
stiffness. At present, there is no reason to believe that spine tolerance to
loads increases with belts. …..

RESULTS: Intramuscular pressure of the erector spinae muscles increased
significantly by wearing the abdominal belt during Valsalva maneuvers and
during maximum isometric lifting exertions, while maximum isometric lifting
capacity and peak intra-abdominal pressure were not affected. Integrated EMG
of rectus abdominis increased significantly by wearing the abdominal belt
during Valsalva maneuvers (after full inspiration) and during isometric leg
lifting.

CONCLUSIONS: Wearing abdominal belts raises intramuscular pressure of the
erector spinae muscles and appears to stiffen the trunk. Assuming that
increased intramuscular pressure of the erector spinae muscles stabilizes the
lumbar spine, wearing abdominal belts may contribute to the stabilization
during lifting exertions