Lucia and colleagues [1] recently reported a case study in which a
Spanish elite long jumper was identified as being α-actinin-3
deficient, owing to carrying the X/X genotype of the R577X polymorphism in
the ACTN3 gene. The authors suggest that the case provides a “notable”
exception to the idea that ACTN3 represents “the ‘gene for speed’,” taking
out of context a question posed in a recent review b...
Lucia and colleagues [1] recently reported a case study in which a
Spanish elite long jumper was identified as being α-actinin-3
deficient, owing to carrying the X/X genotype of the R577X polymorphism in
the ACTN3 gene. The authors suggest that the case provides a “notable”
exception to the idea that ACTN3 represents “the ‘gene for speed’,” taking
out of context a question posed in a recent review by MacArthur and North
[2]. In their review, MacArthur and North consider the evidence for ACTN3
as ‘a’ potential gene important for muscle power performance, and in fact
emphasize the “subtle effect” and “apparent benefit” for the gene on
performance. Such words reflect the fact that muscle power and power-
related performance are undoubtedly highly complex traits, governed by
multiple genetic and environmental factors [3]. That ACTN3 may be a
contributing gene for speed/power is certainly supported by several
studies [4]. A notable feature of the present case is that it is the only
elite-level strength or power athlete reported to date to be α-
actinin-3 deficient [5, 6], providing indirect support for the hypothesis
that α-actinin-3 is an important contributor to muscle power
performance.
Stephen M. Roth, Ph.D.
Department of Kinesiology
University of Maryland
College Park, MD 20742
References
1. Lucia, A, J Olivan, F Gomez-Gallego, C Santiago, M Montil, and C
Foster. Citius and longius (faster and longer) with no alpha- actinin-3 in
skeletal muscles? Br J Sports Med 2007; 41: 616-617.
2. MacArthur, DG and KN North. A gene for speed? The evolution and
function of alpha-actinin-3. Bioessays 2004; 26(7): 786-95.
3. Beunen, G and M Thomis. Gene powered? Where to go from
heritability (h2) in muscle strength and power? Exerc Sport Sci Rev 2004;
32(4): 148-54.
4. MacArthur, DG and KN North. ACTN3: A genetic influence on muscle
function and athletic performance. Exerc Sport Sci Rev 2007; 35(1): 30-4.
5. Yang, N, DG MacArthur, JP Gulbin, AG Hahn, AH Beggs, S Easteal, et
al. ACTN3 genotype is associated with human elite athletic performance.
Am.J.Hum.Genet. 2003; 73: 627-631.
6. Niemi, AK and K Majamaa. Mitochondrial DNA and ACTN3 genotypes in
Finnish elite endurance and sprint athletes. Eur J Hum Genet 2005; 13(8):
965-9.
In the last issue of the journal, a review of tennis elbow and its
management in tennis players appears. It is disappointing to see that the
journal publishes a review with misleading treatment recommendations. The
review article suffers from the inherent weaknesses of the narrative
review form with an unjustified favourisation of "promising"
pharmacological and surgical interventions. Physical inte...
In the last issue of the journal, a review of tennis elbow and its
management in tennis players appears. It is disappointing to see that the
journal publishes a review with misleading treatment recommendations. The
review article suffers from the inherent weaknesses of the narrative
review form with an unjustified favourisation of "promising"
pharmacological and surgical interventions. Physical interventions are not
even mentioned in the conclusion, and the authors state that there is “no
scientific evidence regarding the efficacy in the long term of the
currently used conservative treatment options”. In addition, they
recommend that “a wait-and-see approach is initially advised, as long-term
results do not differ significantly between groups, but if complaints
persist, a surgical approach can be considered”.
In the treatment section of the review, steroid injections are claimed to
be beneficial in the short term and not significantly different from other
treatments in the long and intermediate term. This statement does not
reflect the available evidence. Physiotherapy is acting faster than wait-and-see with significantly better results at 6 weeks [1], while
physiotherapy is significantly better than steroid injections at 12, 26
and 52 weeks [2]. Thus, from a safety perspective it can be concluded that
steroid injections increase the risk for chronic disability and possible
permanent tendon damage [3]. It remains unanswered whether this negative
effect is reversible or not in a timeframe beyond one year. Consequently,
steroid injections should be discouraged in the management of tennis
elbow.
Regarding surgery, there is a scarcity of randomized controlled trials,
and we found only one randomized trial showing no difference over botox
injections [4]. The self-limiting nature of tennis elbow with scientific
evidence showing a 92% success rate at 1 year after physiotherapy [2],
leaves no place for surgery with the inherent risks and lack of documented
effects in tennis elbow management.
The final word about the contents of an optimal physiotherapy package for
tennis elbow has probably not been said. The review cites two references
with low level laser therapy (LLLT) reviews, which have missed large parts
of the LLLT literature, and fail to address the validity of doses and LLLT
procedures. Three LLLT-trials with positive results which we included in
our 2001 LLLT-review of tendinopathies[5] were omitted from these reviews.
One of the omitted trials showed a significantly positive short-term
effect for LLLT over placebo in recreational tennis players [6]. Another
two LLLT trials with exercise therapy regimens in tennis elbow from 2007
show that the addition of 904 nm LLLT with valid doses provides
significantly faster pain-relief than placebo LLLT and exercises [7, 8].
From the above, modification of sports activity and an active approach
with a physiotherapy package containing exercises, stretching,
mobilisation and possibly LLLT emerges as the new gold standard in tennis
elbow management. There is certainly no need to consider steroid
injections or surgery for the average patient with tennis elbow
complaints, when effective risk-free alternatives exist.
References
1. Bisset, L., et al., Mobilisation with movement and exercise,
corticosteroid injection, or wait and see for tennis elbow: randomised
trial. BMJ, 2006. 333(7575): 939.
2. Bisset, L., et al., Conservative treatments for tennis elbow do
subgroups of patients respond differently? Rheumatology (Oxford), 2007.
46(10): 1601-5.
3. Smidt, N. and D.A. van der Windt, Tennis elbow in primary care.
BMJ, 2006. 333(7575): 927-8.
4. Keizer, S.B., et al., Botulinum toxin injection versus surgical
treatment for tennis elbow: a randomized pilot study. Clin Orthop Relat
Res, 2002(401): 125-31.
5. Bjordal, J., C. Couppé, and A. Ljunggreen, Low level laser therapy
for tendinopathy. Evidence of a dose-response pattern. Physical Therapy
Reviews, 2001. 6(2): 91-99.
6. Palmieri, B., Stratified double blind crossover study on tennis
elbow in young amateur athletes using infrared lasertherapy. Medical Laser
Report, 1984. 1: 1.
7. Lam, L.K. and G.L. Cheing, Effects of 904-nm Low-Level Laser
Therapy in the Management of Lateral Epicondylitis: A Randomized
Controlled Trial. Photomed Laser Surg, 2007. 25(2): 65-71.
8. Stergioulas, A., Effects of low-level laser and plyometric
exercises in the treatment of lateral epicondylitis. Photomed Laser Surg,
2007. 25(3): 205-13.
Being that women are 6-10 times more likely to suffer from knee
injuries or anterior knee pain, perhaps clinical significance would be
improved if mainly females were tested.
Re:Do you get value for money when you buy an expensive pair of running shoes? [1]
When the ground-force-reaction is measured as a function of time
during running or walking, the result is a function of speed and underfoot
conditions [2]. At any speed, however, the area
under the force-time plot represents the total momentum change during the
stance phase of gait. This cannot be altered by any...
Re:Do you get value for money when you buy an expensive pair of running shoes? [1]
When the ground-force-reaction is measured as a function of time
during running or walking, the result is a function of speed and underfoot
conditions [2]. At any speed, however, the area
under the force-time plot represents the total momentum change during the
stance phase of gait. This cannot be altered by any shoe design, since the
consequence would be that the runner would either rise up into the air or
sink lower and lower with bent knees. At the start of the contact phase,
the centre of mass of the runner is moving downwards. At the end of the
contact phase, the centre of mass is moving upwards – the motion must be
exactly reversed. Attempts to find a design of running shoe that will
alter the ground-force-reaction are doomed to failure for this reason.
It was shown, however, by McMahon & Greene [3]that if the underfoot
compliance were to be chosen in the range 100-200kN/m, then the spike seen
in the GRF-time plot, as a result of heel impact, will not be observed.
The basic premise of Clinghan et al, that changes should be
detectable in the GRF as a result of differences in shoe design between
expensive and inexpensive shoes, may be seen to be one that would not
survive experimental inquiry. In fact, their results were defined before
any tests were carried out, since no differences can be found.
The fact that differences were seen between different areas of the
foot may be put down to experimental variation, and the fact that while
the GRF cannot be changed radically, it is possible to redistribute the
force across the foot.
References
1. Clinghan R T, Arnold G P,Drew T S, Cochrane L, and Abboud R J
Do you get value for money when you buy an expensive pair of running shoes?
Br J Sports Med 2007.038844v1
2.Walker CA & Blair R Leg stiffness and damping factors as a function of
running speed, Sports Engineering 2002, 5, 129-139.
3. McMahon TA & Greene PR The influence of track compliance on
running, J. Biomech. 1979, 12, 893-904.
Despite the measures you have outlined athletes even of the age group you are referring still get injured. Of the measures you have highlighted I believe is only a part of the strategies to injury in sport. In rugby union a study by Chalmers et al (2004)[1] were of the view that coaches had a significant role to preventing injuries, although there has been no study to address that issue it would seem that ou...
Despite the measures you have outlined athletes even of the age group you are referring still get injured. Of the measures you have highlighted I believe is only a part of the strategies to injury in sport. In rugby union a study by Chalmers et al (2004)[1] were of the view that coaches had a significant role to preventing injuries, although there has been no study to address that issue it would seem that ought to be considered in any injury prevention strategy. In reference to pre season team conditioning, how relevant are the exercises that so many athletes undertake in the off season? For rugby union I would think Sevens rugby would be an appropriate off season programme because the game itself simulates the 15's game in most respects. Furthermore, the strategy must take into account the concept of the game and the application of the Laws, Rules of that code, none of these issues were addressed.
References
1.Chalmers, D. J., Simpson, J. C., & Depree, R. (2004). Tackling Rugby injury: lessons learned from the implementation of a five-year sports injury prevention program. Journal of Science and Medicine in Sport, 7(1), 74-84.
What is important is that coaches must apply the Laws when coaching the game. Referees however must apply the Laws when refereeing at any level of competition. At the Rugby World Cup the post tackle events and the ruck were consistently poorly refereed. Only the tackled player and the tackler(s) are permitted to be off their feet and no one else. In the matter of the scrum that Law prohibits the front rows f...
What is important is that coaches must apply the Laws when coaching the game. Referees however must apply the Laws when refereeing at any level of competition. At the Rugby World Cup the post tackle events and the ruck were consistently poorly refereed. Only the tackled player and the tackler(s) are permitted to be off their feet and no one else. In the matter of the scrum that Law prohibits the front rows from charging towards each other. Another important issue is the repetitive contacts between players in the tackle situation and the scrum which over time develops into chronic tissue damage. Such events have led to instability of the shoulder and the acj joints affecting the tackler and premature degeneration of the cervical spine in front row forwards. The study on post match tackle injuries by Takarada (2003)[1] highlights the effects of the contacts made at the tackle.I believe the tackle law can deserve another update.
References
1.Takarada, Y. (2003). Evaluation of muscle damage after a rugby match with special reference to tackled players. British Journal of Sports Medicine, 37(5), 416-419.
The International Rugby Board. (2007). Laws of the game. Dublin: The International Rugby Board.
I read with great interest the recent review focussing the
pathophysiology, the diagnosis and the treatment of tennis elbow. However,
based on this report I would appreciate having the chance to comment on
some issues raised by the authors shortly.
Diagnosis: The role of neovascularisation determined by colour or
even better by Power Doppler sonography has been mentioned for several
sites...
I read with great interest the recent review focussing the
pathophysiology, the diagnosis and the treatment of tennis elbow. However,
based on this report I would appreciate having the chance to comment on
some issues raised by the authors shortly.
Diagnosis: The role of neovascularisation determined by colour or
even better by Power Doppler sonography has been mentioned for several
sites with painful tendons. Besides both, mid-portion and insertional
Achilles tendinopathy [8], patellar tendinopathy [6], supraspinatus
tendinopathy [1] as well as tennis elbow and wrist tendinopathy [7] have
been reported to be associated with neovascularisation which is closely
related to pain. Therefore the role of colour and Power Doppler sonography
can currently not be overestimated based on these reports, which is not
reflected in the review.
The effect of elbow position on grip strength as an easy measure in
the evaluation of tennis elbow should be mentioned here [4]. The grip
strength was tested in full extension of the elbow and in 90° flexion.
Strength was no different in flexion and extension for the healthy
extremity and 29% stronger in flexion than in extension for the affected
extremity. The affected arm averaged 50% of the strength of the healthy
arm in extension and 69% of the strength of the healthy arm in flexion.
These differences were statistically significant. An 8% difference in grip
strength between flexion and extension was found to be 83% accurate in
distinguishing the affected from the unaffected extremities.
Conservative treatment: A recent analysis of 383 patients suffering
tennis elbow from two randomized trials investigated wait-and-see policy,
corticosteroid injections and physiotherapy [2]. Based on individual
patient data from both trials, they found that corticosteroid injections
were statistically and clinically superior at 6 weeks, but significantly
worse at 52 weeks compared with both wait-and-see and physiotherapy.
I agree with the authors of the review that further randomized-
controlled trials are warranted focussing for example the use of eccentric
training in tennis elbow. However, given the results at the Achilles and
the patellar tendon level, one could speculate that an appropriate painful
eccentric training at the elbow and forearm level ameliorates recovery in
tennis elbow, but studies are pending.
Surgery: Recently a ten- to 14-year follow-up has been published
among 139 consecutive patients suffering tennis elbow which were operated
on by a single surgeon between 1991 and 1994 [5]. The overall improvement
rate was 97%. Patient satisfaction averaged 8.9 of 10. Ninety-three
percent of those available at a minimum of 10-year follow-up reported
returning to their sports.
Evidence-based medicine: Bottom line should be the recent reference
by Dr. Cowan and coworkers. They analysed the quality of prospective
controlled randomized trials [3]. The use of the gold-standard trial
design, the prospective randomized therapeutic study (Level-I or II
evidence), does not ensure quality research or reporting. Critical
analysis of scientific work is important regardless of the study design.
Clinical scientists should be familiar with the CONSORT criteria and
adhere to them when reporting clinical trials.
References
[1] Alfredson H, Harstad H, Haugen S, Ohberg L, Sclerosing
polidocanol injections to treat chronic painful shoulder impingement
syndrome-results of a two-centre collaborative pilot study. Knee Surg
Sports Traumatol Arthrosc. 2006;14(12):1321-6
[2] Bisset L, Smidt N, Van der Windt DA, Bouter LM, Jull G, Brooks P,
Vincenzino B. Conservative treatments for tennis elbow do subgroups of
patients respond differently? Rheumatology (Oxford) 2007;46(10):1601-5.
[3] Cowan J, Lozano-Calderon S, Ring D. Quality of prospective
controlled randomized trials. Analysis of trials of treatment for lateral
epicondylitis as an example. J Bone Joint Surg Am 2007;89:1693-9.
[4] Dorf ER, Chhabra AB, Golish SR, McGinty JL, Pannunzio ME. Effect
of elbow position on grip strength in the evaluation of lateral
epicondylitis. J Hand Surg [Am] 2007;32:882-6.
[5] Dunn JH, Kim JJ, Davis L, Nirschl RP. Ten- to 14-year follow-up
of the Nirschl surgical technique for lateral epicondylitis. Am J Sports
Med 2007 Nov 30 [Epub ahead of print].
[6] Gisslen K, Alfredson H. Neovascularisation and pain in jumper`s
knee: a prospective clinical and sonographic study in elite junior
volleyball players. Br J Sports Med 2005;39:423-8.
[7] Knobloch K, Spies M, Busch KH, Vogt PM. Sclerosing therapy and
eccentric training in flexor carpi ulnaris tendinopathy in a tennis
player. Br J Sports Med 2007;41:920-1.
[8] deVos RJ, Weir A, Cobben LP, Tol JL. The value of power Doppler
ultrasonography in Achilles tendinopathy: a prospective study. Am J Sports
Med 2007;35:1696-701.
In a recent letter,[7] Noakes reminded us that the brain estimates
the maximal exercise duration that can be sustained (maybe even before the
exercise begins), and then uses the ratings of perceived exertion (RPE) to
inform the body when the exercise will and must terminate. I agree with
this suggestion. RPE attests to the exercise intensity, but also to the
duration.[3] Therefore, according to Noake...
In a recent letter,[7] Noakes reminded us that the brain estimates
the maximal exercise duration that can be sustained (maybe even before the
exercise begins), and then uses the ratings of perceived exertion (RPE) to
inform the body when the exercise will and must terminate. I agree with
this suggestion. RPE attests to the exercise intensity, but also to the
duration.[3] Therefore, according to Noakes,[7, 8] RPE is a predictor of
the exercise duration that remains until exhaustion. However, RPE is not
the only perceptual tool that informs us of the exercise end point, and
perhaps not the most effective.
Drawing from the “teleoanticipation” concept,[9] prior to, or early
in an exercise period, the brain estimates the time limit (i.e., Tlim)
that can safely sustained.[8] Then, this predicted Tlim is associated with
the maximal RPE that can be tolerated. During exercise, the brain provides
RPE, which increases as a function of the percentage of the predicted
Tlim, until the attainment of the corresponding tolerated maximal RPE.[8]
Garcin and Billat confirmed that RPE attests to both exercise
intensity and duration.[3] However, these authors[3] found similar results
for a second scale (Estimated Time Limit scale, ETL). This scale predicts
how long the current exercise level can be maintained (i.e., the
estimation of exhaustion time). Therefore, as suggested by Noakes,[7] if
humans may accurately predict the exercise duration that they are or will
be able to sustain at any exercise intensity, ETL may be considered as the
conscious interpretation of the Tlim predicted by teleoanticipation, and
may be more effective than RPE in predicting the time remaining before
exhaustion.
The reliability of ETL scale is established.[1, 5] Moreover, although
the accuracy of this scale must be improved, no significant difference was
found between the Tlim predicted from this scale and those that were
actually measured.[1, 2, 4] Therefore, ETL scale may be associated with
the RPE scale (or substituted for the RPE scale, if the accuracy
improves), not to precisely measure the Tlim predicted by
teleoanticipation, but to provide an estimation of this latter, as
recently suggested.[6]
There are no competing interests.
References
1. Coquart, J. B. J. and M. Garcin. Validity and reliability of
perceptually-based scales during exhausting runs in trained male runners.
Percept Mot Skills. 2007;104:254-266.
2. Coquart, J. B. J., M. Garcin, S. Robin, and R. Matran. Prediction of
exhaustion time from a perceptually-based scale. In 12th International
Congress of the Association des Chercheurs en Activités Physiques et
Sportives. Leuven, Belgium, p. 68, 2007.
3. Garcin, M. and V. Billat. Perceived exertion scales attest to both
intensity and exercise duration. Percept Mot Skills. 2001;93:661-671.
4. Garcin, M., L. Mille-Hamard, and V. Billat. Influence of aerobic
fitness level on measured and estimated perceived exertion during
exhausting runs. Int J Sports Med. 2004;25:270-277.
5. Garcin, M., M. Wolff, and T. Bejma. Reliability of rating scales of
perceived exertion and heart rate during progressive and maximal constant
load exercises till exhaustion in physical education students. Int J
Sports Med. 2003;24:285-290.
6. Joseph, T., B. Johnson, R. A. Battista, G. Wright, C. Dodge, J.P.
Porcari, J. J. De Koning, and F. Foster. Perception of fatigue during
simulated competition. Med Sci Sports Exerc. 2008;40:381-386.
7. Noakes, T. D. RPE as a predictor of the duration of exercise that
remains until exhaustion. Br J Sports Med Oneline [eLetter] 8 January
2008. http://bjsm.bmj.com/cgi/content/abstract/bjsm.2007.043612v1
8. Noakes, T. D., R. J. Snow, and M. A. Febbraio. Linear relationship
between the perception of effort and the duration of constant load
exercise that remains. J Appl Physiol. 2004;96:1571-1573.
9. Ulmer, H. V. Concept of an extracellular regulation of muscular
metabolic rate during heavy exercise in humans by psychophysiological
feedback. Experientia. 1996;52:416-420.
We have read with great interest the article by Silva et al and
acknowledge their innovating and pioneering work in the field of shoulder
dyskinesia. Their research uncovered a greater dynamic reduction in
subacromial space in tennis players with shoulder dyskinesia (19.3 mm),
compared to tennis players without shoulder dyskinesia (13.8 mm). The
authors claim there would be an average difference in dy...
We have read with great interest the article by Silva et al and
acknowledge their innovating and pioneering work in the field of shoulder
dyskinesia. Their research uncovered a greater dynamic reduction in
subacromial space in tennis players with shoulder dyskinesia (19.3 mm),
compared to tennis players without shoulder dyskinesia (13.8 mm). The
authors claim there would be an average difference in dynamic reduction of
5.2 mm between these groups. It is improbable to have a 19.3 mm reduction
in subacromial space, considering the fact that the largest subacromial
space in normal individuals is 17 mm.[1] Most likely, some error has
occurred and these values should be divided by a factor ten. In a study by
Herbert et al a reduction in subacromial space of approximately 2 mm was
found between zero and 70 degrees abduction.[2] Values of 1.93 and 1.38 mm
instead of 19.3 and 13.8 mm seem therefore more realistic. This implies
that the average difference in reduction between shoulders with and
without dyskinesia should be 0.52 mm in stead of 5.2 mm.
We question the fact whether ultrasonographic measurement of the
subacromial space is accurate enough to detect such a small difference.
Preliminary results from our own study addressing the issue of
reproducibility of ultrasonographic measurement of the subacromial space,
indicate that an experienced radiologist is capable of reaching an
accuracy of approximately 1 mm (figure 1). This implies that the
difference of 0.52 mm in dynamic reduction falls within the measurement
error of ultrasonographic measurement of the subacromial space. So, even
though Silva et al found a statistically significant difference in dynamic
reduction in subacromial space in shoulders with and without dyskinesia,
the clinical consequence remains unclear. Additional research is therefore
necessary to investigate the clinical use for this promising new
technique.
Figure 1: Bland-Altman-Plot showing difference between measurements plotted against their average for ultrasonograhic measurement of the acromiohumeral distance at zero degrees abduction (cm).
References
1. Azzoni, R.; Cabitza, P.; and Parrini, M.: Sonographic evaluation
of subacromial space. Ultrasonics 2004; 42(1-9): 683-7.
2. Hebert, L. J.; Moffet, H.; Dufour, M.; and Moisan, C.:
Acromiohumeral distance in a seated position in persons with impingement
syndrome. J Magn Reson Imaging 2003; 18(1): 72-9.
Dear Editor,
Lucia and colleagues [1] recently reported a case study in which a Spanish elite long jumper was identified as being α-actinin-3 deficient, owing to carrying the X/X genotype of the R577X polymorphism in the ACTN3 gene. The authors suggest that the case provides a “notable” exception to the idea that ACTN3 represents “the ‘gene for speed’,” taking out of context a question posed in a recent review b...
Dear editor
In the last issue of the journal, a review of tennis elbow and its management in tennis players appears. It is disappointing to see that the journal publishes a review with misleading treatment recommendations. The review article suffers from the inherent weaknesses of the narrative review form with an unjustified favourisation of "promising" pharmacological and surgical interventions. Physical inte...
Dear editor
Being that women are 6-10 times more likely to suffer from knee injuries or anterior knee pain, perhaps clinical significance would be improved if mainly females were tested.
Dear editor
Re:Do you get value for money when you buy an expensive pair of running shoes? [1]
When the ground-force-reaction is measured as a function of time during running or walking, the result is a function of speed and underfoot conditions [2]. At any speed, however, the area under the force-time plot represents the total momentum change during the stance phase of gait. This cannot be altered by any...
Dear Editor
Despite the measures you have outlined athletes even of the age group you are referring still get injured. Of the measures you have highlighted I believe is only a part of the strategies to injury in sport. In rugby union a study by Chalmers et al (2004)[1] were of the view that coaches had a significant role to preventing injuries, although there has been no study to address that issue it would seem that ou...
Dear Editor
What is important is that coaches must apply the Laws when coaching the game. Referees however must apply the Laws when refereeing at any level of competition. At the Rugby World Cup the post tackle events and the ruck were consistently poorly refereed. Only the tackled player and the tackler(s) are permitted to be off their feet and no one else. In the matter of the scrum that Law prohibits the front rows f...
Dear editor,
I read with great interest the recent review focussing the pathophysiology, the diagnosis and the treatment of tennis elbow. However, based on this report I would appreciate having the chance to comment on some issues raised by the authors shortly.
Diagnosis: The role of neovascularisation determined by colour or even better by Power Doppler sonography has been mentioned for several sites...
Dear Editor,
In a recent letter,[7] Noakes reminded us that the brain estimates the maximal exercise duration that can be sustained (maybe even before the exercise begins), and then uses the ratings of perceived exertion (RPE) to inform the body when the exercise will and must terminate. I agree with this suggestion. RPE attests to the exercise intensity, but also to the duration.[3] Therefore, according to Noake...
Dear Editor
We have read with great interest the article by Silva et al and acknowledge their innovating and pioneering work in the field of shoulder dyskinesia. Their research uncovered a greater dynamic reduction in subacromial space in tennis players with shoulder dyskinesia (19.3 mm), compared to tennis players without shoulder dyskinesia (13.8 mm). The authors claim there would be an average difference in dy...
I suggest the basis of the Ezzatvar, et al., report is increased dehydroepiandrosterone (DHEA). It is known exercise increases DHEA. It is my hypothesis of 2020 that low DHEA is linked to the severity of Covid-19 infection and subsequent pathology (© Copyright 2020, James Michael Howard, Fayetteville, Arkansas, U.S.A.) New research, 2022, regarding DHEA has been published that supports my hypothesis that severe Covid-19 illness is associated with low DHEA: “COVID-19 patients with altered steroid hormone levels are more likely to have higher disease severity,” ( 2022 Jul 30. doi: 10.1007/s12020-022-03140-6.) “DHEA was an independent indicator of the disease severity with COVID-19.”
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