While aiming, the bow's tremor concentrates around two frequencies

The summary today

The only measurement of the spectrum of bow tremor while aiming comes from a Japanese engineering group, in 2017, which wanted to tune a damper to the person shooting: accelerometers at three points on the sight, sampling at 500 Hz for five seconds, three people seated with the bow at full draw, and nothing to say they were archers. The published spectrum belongs to a single person, measured three times in the direction with the largest amplitude: the amplitude changes each time, while two peaks, near 8 and 14 Hz, stay where they are. Whether they are the same in everyone is not shown, which is why the claim itself gives no figures. In the example of the model fit, done on the three directions together, the peaks sit at 4.6 and 12.8 Hz, and the two dampers built for two further people are tuned to 9.30 and 8.70 Hz. The measurements were taken seated precisely to remove trunk and leg sway below 3 Hz, so they say nothing about what happens standing on the shooting line. In 2020 another group, tracking bow movement in five intermediate and expert archers, treats everything above 5 Hz as the bow's own vibration and filters it out: it is a methodological choice rather than a measurement, but it assigns to the equipment a band the first study calls tremor, and nobody has set the two readings side by side.

Also phrased as: "tremor frequency while aiming"; "sight vibration while aiming"; "physiological tremor and the bow"; "damper tuned to tremor"; "the shaking sight pin"; "bow tremor at 8 and 14 Hz"

Evidence

• 2017
  For General population Published later

  Accelerometers at three points on the sight, sampling at 500 Hz for 5 seconds, 3 people seated with the bow at full draw, with no information on their shooting experience: the published spectrum, from one person, shows two dominant peaks near 8 and 14 Hz in the direction with the largest amplitude.

  Suppression of tremor on bow by using dynamic vibration absorber · Yusuke Mizuno, Ikuma Ikeda, Nobuyuki Iwatuki

• 2017
  For General population Published later

  Three repeated measurements on the same participant: the acceleration amplitude is different each time, while the two peaks around 8 and 14 Hz are always there.

  Suppression of tremor on bow by using dynamic vibration absorber · Yusuke Mizuno, Ikuma Ikeda, Nobuyuki Iwatuki

• 2017
  Context General population Published later

  The frequencies differ from one graph to the next: in the example of the model fit, done on the amplitude of the three directions together, the peaks sit at 4.6 and 12.8 Hz, and the two dampers built for two other people are tuned to 9.30 and 8.70 Hz (aluminium beams of 23.5 and 26.5 millimetres with 60 grams at the tip).

  Suppression of tremor on bow by using dynamic vibration absorber · Yusuke Mizuno, Ikuma Ikeda, Nobuyuki Iwatuki

• 2017
  Context General population Published later

  The analysis looks only at the band between 3 and 20 Hz: below 3 Hz the authors treat movement as voluntary sway of trunk and legs, above 20 Hz the amplitude is negligible. To remove the former, participants drew the bow seated.

  Suppression of tremor on bow by using dynamic vibration absorber · Yusuke Mizuno, Ikuma Ikeda, Nobuyuki Iwatuki

• 2020
  Context Archers Published later

  Angular velocities of the Olympic bow in 5 intermediate and expert archers: to remove the bow's own vibration from the movement data the authors apply a low-pass filter with a 5 Hz pass band and a 10 Hz stop band. It is a methodological choice, not a measurement of the spectrum.

  Archery shots visualization by clustering and comparing from angular velocities of bows · Midori Kawaguchi, Hironori Mitake, Shoichi Hasegawa

Status history

1. 2017 Transferred The first spectrum comes from an engineering study that wants to tune a damper to bow tremor. Accelerometers at three points on the sight, 500 Hz for five seconds, three people seated at full draw, with nothing to say whether they shoot. The spectrum shown belongs to a single person measured three times: two dominant peaks near 8 and 14 Hz, with the amplitude changing from one repetition to the next and the peaks staying put. In the example of the model fit, though, the peaks sit at 4.6 and 12.8 Hz, and the dampers for two more people are tuned to 9.30 and 8.70. The tremor measured is that of ordinary people, seated, not of archers on the line: transferred.
2. 2020 Transferred A group using an angular velocity sensor to measure the movement of the Olympic bow in five intermediate and expert archers filters out everything above 5 Hz, treating it as the bow's own vibration rather than the archer's movement. It does not measure the spectrum, so it adds nothing on the two peaks, but it reads as equipment vibration the band that in 2017 had been called tremor. There is still no spectrum from archers, and the status stays transferred, with one more question about what that band actually is.

Related

Related articles

• Bow arm tremor in archery: why it happens and how to reduce itBow arm shake at full draw is two movements, a slow sway and a fast tremor. What the studies measure, where the tremor comes from and how to reduce it.

Research lines

• 27 studiesTremor and sway while aiming: telling two phenomena apart since 1990
• 35 studiesTeaching and learning archery: sixty years of instructional trials

Other claims in this domain

• CorroboratedAlong its flight the arrow loses an appreciable part of its launch speed12 studiesStatus since 2011
• CorroboratedAs it leaves the bow, the arrow flexes and snakes around the riser instead of leaving straight19 studies · 47 archers measuredStatus since 2012
• ReportedA camera-based scoring system misreads some arrows: the ones barely sticking out and the ones that shift the target face7 studies · 2 archers measuredStatus since 2017
• ReportedA chest band with fibre optic sensors measures breathing and mean heart rate with small errors, and an archer can wear it while shooting2 studiesStatus since 2019
• ReportedA compound bow stores between 70 and 100 joules and sheds about two thirds of the force at full draw4 studiesStatus since 2015

See all claims on equipment and tuning