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Juerg Feldmann

Fortiori Design LLC
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Posts: 1,530
 #1 
A  common  question  over the last few  weeks.
  Does it matter, where I mount the MOXY unit.
A;  Yes  and no.
  If you look at trends  it does not matter. We did  test on the quadriceps  on vastus lateralis  ,  medialis  and  rectus  with three moxy's  at the same time.
  Result: Different  " absolute "  SmO2  numbers, . Same trends  in all.  ( As usual  exceptions.
depending on your  leg extension angel  the vastus  medialis   is  different  , when you restrict the extension to the last 5  - 10 degrees.  In the neutral zero   international    ROM  language  meaning  if you go  form Ext/ Flex  ( 0/0/10 ). Than you have very little  information in  the other two   but only if you have a  90  degree  hipflexion.
. For  users  on a bike or running or rowing  very little difference   . So  if you test  on a specific  area  than keep the same  area  when you work it  as  close as possible  and  you will have a very accurate  repetition of  the  trends  as well as  of SmO2.
  In this cases  you can see  changes    and  can make some  conclusions.
 Can you   make a conclusion , what may happen in the  other  leg  or   in the upper body.
 Same  again, yes  and no.
   The  best  is to actually  compare  the two legs  in sports , where a  symmetrical  work is crucial for performance.  ( Biking , running,  rowing and so on.  Here you can use  left and right leg  MOXY as you easy  can afford this now, in fact you can buy 12  moxy   for the same cost as a traditional NIRS  and still be cheaper.
  Same wave length  so same info  in trend  for sure.
. Examples  what we do.
   Left and right leg  moxy in sports  like Speed skating ,  rowing   cycling  for example.
 Upper  and lower body MOXY in sports like cross country  skiing  , rowing,    wrestling    for example.
  MOXY  in upper  , lower  body  and  on a respiratory  muscle  to see,  when   an how  core stability  may fall apart  due  to  priority  to breathing than   core stability.
  Here   accepted  studies   who support our crazy ideas.
   First    symmetric  question, second   Postural    challenge  when respiration  is the Limiter.

Asymmetry of quadriceps muscle oxygenation during elite short-track speed skating.

Hesford CM, Laing SJ, Cardinale M, Cooper CE.

Source

Department of Biological Sciences, University of Essex, United Kingdom. chesfo@essex.ac.uk

Abstract

PURPOSE:

It has been suggested that, because of the low sitting position in short-track speed skating, muscle blood flow is restricted, leading to decreases in tissue oxygenation. Therefore, wearable wireless-enabled near-infrared spectroscopy (NIRS) technology was used to monitor changes in quadriceps muscle blood volume and oxygenation during a 500-m race simulation in short-track speed skaters.

METHODS:

Six elite skaters, all of Olympic standard (age = 23 ± 1.8 yr, height = 1.8 ± 0.1 m, mass = 80.1 ± 5.7 kg, midthigh skinfold thickness = 7 ± 2 mm), were studied. Subjects completed a 500-m race simulation time trial (TT). Whole-body oxygen consumption was simultaneously measured with muscle oxygenation in right and left vastus lateralis as measured by NIRS.

RESULTS:

Mean time for race completion was 44.8 ± 0.4 s. VO2 peaked 20 s into the race. In contrast, muscle tissue oxygen saturation (TSI%) decreased and plateaued after 8 s. Linear regression analysis showed that right leg TSI% remained constant throughout the rest of the TT (slope value = 0.01), whereas left leg TSI% increased steadily (slope value = 0.16), leading to a significant asymmetry (P < 0.05) in the final lap. Total muscle blood volume decreased equally in both legs at the start of the simulation. However, during subsequent laps, there was a strong asymmetry during cornering; when skaters traveled solely on the right leg, there was a decrease in its muscle blood volume, whereas an increase was seen in the left leg.

CONCLUSIONS:

NIRS was shown to be a viable tool for wireless monitoring of muscle oxygenation. The asymmetry in muscle desaturation observed on the two legs in short-track speed skating has implications for training and performance

 

Postural activity of the diaphragm is reduced in humans when respiratory demand increases
Paul W Hodges, Inger Heijnen, and Simon C Gandevia
Prince of Wales Medical Research Institute and University of New South Wales, Sydney, Australia
Corresponding author P. W. Hodges: Department of Physiotherapy, The University of Queensland, Brisbane, QLD 4072, Australia. Email: p.hodges@shrs.uq.edu.au
Received April 27, 2001; Accepted August 29, 2001.
  • Respiratory activity of the diaphragm and other respiratory muscles is normally co-ordinated with their other functions, such as for postural control of the trunk when the limbs move. The integration may occur by summation of two inputs at the respiratory motoneurons. The present study investigated whether postural activity of the diaphragm changed when respiratory drive increased with hypercapnoea.
  • Electromyographic (EMG) recordings of the diaphragm and other trunk muscles were made with intramuscular electrodes in 13 healthy volunteers. Under control conditions and while breathing through increased dead-space, subjects made rapid repetitive arm movements to disturb the stability of the spine for four periods each lasting 10 s, separated by 50 s.
  • End-tidal CO2 and ventilation increased for the first 60–120 s of the trial then reached a plateau. During rapid arm movement at the start of dead-space breathing, diaphragm EMG became tonic with superimposed modulation at the frequencies of respiration and arm movement. However, when the arm was moved after 60 s of hypercapnoea, the tonic diaphragm EMG during expiration and the phasic activity with arm movement were reduced or absent. Similar changes occurred for the expiratory muscle transversus abdominis, but not for the erector spinae. The mean amplitude of intra-abdominal pressure and the phasic changes with arm movement were reduced after 60 s of hypercapnoea.
  • The present data suggest that increased central respiratory drive may attenuate the postural commands reaching motoneurons. This attenuation can affect the key inspiratory and expiratory muscles and is likely to be co-ordinated at a pre-motoneuronal site.
The central nervous system co-ordinates the motor activities of all trunk muscles, including the diaphragm, during both postural and respiratory tasks.


Exercise-induced respiratory muscle fatigue: implications for performance

1.   Lee M. Romer1 and

2.   Michael I. Polkey2

+ Author Affiliations

1.    1Centre for Sports Medicine and Human Performance, Brunel University, Uxbridge; and 2Respiratory Muscle Laboratory, Royal Brompton Hospital, and National Heart and Lung Institute, London, United Kingdom

1.    Address for reprint requests and other correspondence: L. M. Romer, Centre for Sports Medicine and Human Performance, Brunel Univ., Uxbridge UB8 3PH, United Kingdom (e-mail: lee.romer@brunel.ac.uk)

Next Section

Abstract

It is commonly held that the respiratory system has ample capacity relative to the demand for maximal O2 and CO2 transport in healthy humans exercising near sea level. However, this situation may not apply during heavy-intensity, sustained exercise where exercise may encroach on the capacity of the respiratory system. Nerve stimulation techniques have provided objective evidence that the diaphragm and abdominal muscles are susceptible to fatigue with heavy, sustained exercise. The fatigue appears to be due to elevated levels of respiratory muscle work combined with an increased competition for blood flow with limb locomotor muscles. When respiratory muscles are prefatigued using voluntary respiratory maneuvers, time to exhaustion during subsequent exercise is decreased. Partially unloading the respiratory muscles during heavy exercise using low-density gas mixtures or mechanical ventilation can prevent exercise-induced diaphragm fatigue and increase exercise time to exhaustion. Collectively, these findings suggest that respiratory muscle fatigue may be involved in limiting exercise tolerance or that other factors, including alterations in the sensation of dyspnea or mechanical load, may be important. The major consequence of respiratory muscle fatigue is an increased sympathetic vasoconstrictor outflow to working skeletal muscle through a respiratory muscle metaboreflex, thereby reducing limb blood flow and increasing the severity of exercise-induced locomotor muscle fatigue. An increase in limb locomotor muscle fatigue may play a pivotal role in determining exercise tolerance through a direct effect on muscle force output and a feedback effect on effort perception, causing reduced motor output to the working limb muscles.

*       respiratory muscles

*       exercise

*       diaphragm

*       abdominals

*       magnetic stimulation

*       metaboreflex

the purpose of this minireview is to address the question of whether the respiratory demands of exercise contribute significantly toward exercise limitation, either directly through limitations of the respiratory muscle pump or indirectly through effects on limb blood flow and locomotor muscle fatigue. We describe the mechanical and metabolic costs of meeting the ventilatory requirements of exercise. We then ask whether the respiratory muscles fatigue with exercise, what factors contribute to any such fatigue, and what the implications of these factors are for exercise tolerance. Finally, we deal with the potential mechanisms by which respiratory muscle fatigue could compromise exercise tolerance and whether it is possible to overcome this potential respiratory limitation. Our review focuses on the healthy young adult exercising near sea level. However, we also consider special circumstances that determine the balance between metabolic demand and respiratory system capacity in the highly trained endurance athlete and the clinical implications for respiratory limitations to exercise in patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF).

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #2 
Multiple  MOXY use
  A  question we answered  already.
 Does it matter  where  you place the MOXY.  We  said  Yes and  no.
 The trend is the same  the  key muscle will show the bets   amplitude to see changes.
    We  explained the  case studies  we did on the quadriceps.
 Here another study  confirming our findings  but this on the upper body  done  by UBC    IN Vancouver.

Abstract

The purpose of this study was to determine which upper-limb muscle exhibits the greatest change in muscle deoxygenation during arm-cranking exercise (ACE). We hypothesized that the biceps brachii (BB) would show the greatest change in muscle deoxygenation during progressive ACE to exhaustion relative to triceps brachii (TR), brachioradialis (BR), and anterior deltoid (AD). Healthy young men (n = 11; age = 27 ± 1 y; mean ± SEM) performed an incremental ACE test to exhaustion. Near-infrared spectroscopy (NIRS) was used to monitor the relative concentration changes in oxy- (O2Hb), deoxy- (HHb), and total hemoglobin (Hbtot), as well as tissue oxygenation index (TOI) in each of the 4 muscles. During submaximal arm exercise, we found that changes to NIRS-derived measurements were not different between the 4 muscles studied (p > 0.05). At maximal exercise HHb was significantly higher in the BB compared with AD (p < 0.05). Relative to the other 3 muscles, BB exhibited the greatest decrease in O2Hb and TOI (p < 0.05). Our investigation provides two new and important findings: (i) during submaximal ACE the BB, TR, BR, and AD exhibit similar changes in muscle deoxygenation and (ii) during maximal ACE the BB exhibits the greatest change in intramuscular O2 status

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