Wearing Sense on Underside of Wrist - Good or Bad?

[SamIII]

Is the accuracy of the Sense watch adversely affected if it is worn on the underside of the wrist?

[Guy_]

Hi @SamIII  -  it shouldn't be a problem, it may help for  cases where the button gets pressed accidentally, particularly left handed people, though be careful not to knock it in case the glass breaks.

[LZeeW]

@SamIII   Yes, the heart rate accuracy can be adversely affected by wearing it facing the underside of your wrist.  Heart rate detection uses an emitter/sensor system called reflective photoplethysmography (PPG).  Now bear with me here.  Many of the muscles that control your fingers are in your forearm.  All of the tendons for those muscles are on the underside of the wrist.  Your finger movement causes a type of interference called optical noise.  There is more optical noise on the underside of your wrist than on the outside.  This optical noise is one, but not the complete, reason why wrist worn trackers give incorrect heart rate results.  We love our wrist worn trackers, but the wrist is really an awful place to be taking this measurement.

[Guy_]

@LZeeW  - in theory, but in practice the watch doesn't provide a very accurate readings worn on the top side during exercise, it hardly matters if it's worn underneath. If it means that actions aren't taken inappropriately that would be a good thing.

I wear my various watches both sides and never noticed any problems.

[SamIII]

Thank you for your reply. That makes sense to me. The challenge will be to wear a watch on the top of my wrist after 50 years of wearing it on the underside of my wrist.

Sam

[SamIII]

  What inaccuracies have you found with the data collected by the Sense during exercise?