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Posts: 259
A little over a week ago, we did a 5-1-5 test at Chris Balser's bike fit studio and we observed one of the more extreme Non-Involved Muscle Responses that I've seen.

The test subject was a very powerful cyclist.  The load step 5A and 5B that he completed were well over 400 watts (475 if memory serves correctly)

We had the deltoid sensor poorly attached for the first few load steps, but then got good data after that was corrected.   You will also see a blip in the middle of load step 1B where we needed to make an adjustment to the cadence sensor.

The remarkable aspect of this test was the very low SmO2 in the arms at the end of load step 5B.
SmO2 on Extreme NonInvolved Response.png   
THb on Extreme NonInvolved Response.png 
It's interesting to see how the unsteadiness in the arm SmO2 is somewhat mirrored by the SmO2 in one of the legs but not the other.  This is a zoom in on load step 5B.  (Note that the time synching of the 3 traces might be off by a couple of seconds.)

SmO2 5B.png 

The raw data is attached

Attached Files
xlsx Balser_Test_Deltoid_Response.xlsx (573.26 KB, 18 views)


Development Team Member
Posts: 279
What I also find intruiging is to see the thb suddenly shift to another level at step 3b for the right VL. Did the sensor move? I actually experienced something like that today (when being in a steady state powerlevel (and thb/smo2 level) when the signal dropped. After switching on and off the new signal had a higher steady state SmO2 level. I related that to a shift of the sensor.

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Posts: 1,501
Just playing around  with this data's . Here a  question. Delta placement on the  right or left  side. ?  PLus  do we have a  HR  reading  ?

Posts: 259
Deltoid was on the left side.

I don't have HR data, but maybe Chris Balser does.

THb shift could have been a sensor shift.  They were just tucked under compression clothes with no tape.

Development Team Member
Posts: 264
Hi Roger,

I've seen this kind of pattern once on me (see below-not reproduced since then) 


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Posts: 18
I sent HR to Roger. Left deltoid, and he was not loading this arm during the test. Elbows relaxed and sensor stable. I
Chris Balser

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Posts: 1,501
will be back in combination  with  Danieles  data  set.
 Additional question. On what  part of the delta  was the MOXY  attached. Did you uses a  SEMG   at the same time ?

Posts: 259
We did not have SEMG measurements.

The Moxy was on the lateral deltoid.

Development Team Member
Posts: 1,501
One  more ( possibly more  questions )
 The arm upper body  position, was it in aero position or upright sitting  with top grip on  handle bars.

Development Team Member
Posts: 1,501
More feedback on here.
 1. If we  have a  non involved  . or better  minimal involved  muscle  combined in an assessment  with a very involved muscle  we should have  to very distinct reactions

 1. We have  as a repeat  a local reaction as well a  systemic reaction.

This is  true in many ways  but as well when we look  at vasodilatation.
Systemic vasodilatation  can be triggerd  by  central  drive  and hormonal reactions.
Local  vasodilatation   can be triggered as explain  by metabolic   stimulation, shear forces  and so on.

So   when we start slow  enough so CO is never in problem to maintain BP  we should see in both  muscles  and increase in tHb  and an increase in SmO2.
 But the involved muscle has a fight between  the  CO   and the muscle compression. In a  slow  step test  the CO will not  increase   extreme   and as long the  muscle is happy  there is no need  for sure not  if SmO2   actually increases.
 So lets  see how that may look.

inv  non inv.jpg 

Now  the only   or one of the moments  where the SmO2  would not go up but as well tHb in a noninvolved muscle if there is   immediate  a cardiac  limitation  and therefor  a BP  risk.  You can see nicely this was a  10 min step  assessment.

 Now  the   vasodilatation in the  noninvolved is a centrally regulated  one  and will keep working as  long centrally we are sure we  can  afford this and  can maintain  BP  as well as   pO2.

 Not  our  smarts

centrally vasodillatation.jpg

So when we look Daniele's  three   muscles  RF  VL  and D    and we  take the above  as a feedback it looks like this .

rf d  vll 1  smo2  overlap noninv D.jpg 

Now look his tHB  reactions  of the same three muscles.

thb overlapp all three nin inv D.jpg

You can see  the clear  dip in tHb by D. tHb  drops   as   so often discuss  as a sign of  vasoconstriction.
 a)  systemic   or  local  due to  compression.
 If it is local  due to compression  we  should see as well drop in SmO2  , which we see. 
But   the drop in SmO2  would be  as a  taking of  O2   so HHb will go up  and  O2HB  down in a  symmetrically  way. I take on  O2  so  O2Hb  goes one  down  and HHb goes one  up  as a  super simple  idea.

So lets see the total biased  D  from Daniele  and  from the extreme  drop client. again.
bias  delta  thb bals  real inv.jpg 

All the  assessment time we  never see an actually increase in O2 in this  so called non involved  muscle we always see a  drop in O2Hb   responding  with a  equal increase in HHb as  sign of  O2 used  and  than again delivered  despite  up and down in tHb.

bias  D noninv.jpg 

See in Daniele's  non involved  biased trend.
 In the low intensity a  clear delivery as   he could afford  of  O2  to    minimal active muscles where he  reached a kind of a  " full " level  till he  needed the   energy in his  legs  so   shift  of  blood to the legs  and whit it  of  O2.
 This indicates a delivery limitation. Cardiac  or  respiration. Now look at his  HHb  and O2Hb trend .
 I sit symmetrically is  for  each O2   used  a  drop in O2Hb  and and equal increase in HHb.
 Tish would indicate  O2   used in the  assess D  muscle.
 What can you see  and look when it take s b place  when you take   tHb into consideration.
 If we look  very close it looks again like  this.

bias delta very close  noninv.jpg

Now  if  we go back to the  surprising low  SmO2  case  look at his  D  tHb  and SmO2 trend.
 He has no sign  of a  vasoconstriction but a   cleat  ongoing blood supply   but a  drop in SmO2   combined  with his  symmetrical biased  picture  would confirm , that his  D was  despite  the idea  very nicely involved in the  activity  as a  stabilizer  for  example
. bals  delta  thb  smo2 bals.jpg 

Summary. The trend in O2Hb  and HHb  can be used to see, whether it is  an occlusion , a re --utilitsation or  a ,in this  case ,shift of O2  to  a different body part.
 Question. How would an occlusion trend  look   when we assess HHb  and  O2Hb trends.
 How could a  re saturation look if  we load  more O2  than we  use.
 Think the opposite in question one. we    can not get rid  of HHb  so  what would happend there. ?

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