https://matteocampagna.com/en/registry/physical-training/instrumented-riser-draw-strength Changes to this claim in Matteo Campagna's evidence registry: its status, its year-by-year history, revisions of the page. en-gb https://matteocampagna.com/en/registry/physical-training/instrumented-riser-draw-strengthThere is only one device, the Holding Bow Digitec Test: a wooden riser connected to an 80 kg spring read by a load sensor, developed in Indonesia and validated in 2022 on 33 adult club and university archers, 18 men and 15 women aged 20 to 23. The same sample was published twice, in a regional journal and in conference proceedings, and counts as one study. Against the manual test the measurement agrees for strength (r = 0.939) and more closely still for holding time (r = 0.974), and in the table of measurements the means almost coincide: 18.18 against 18.54 kg and 20.34 against 20.48 seconds. The report is not clean, though. The later tables give a mean digital strength of 17.94 kg over two trials, different from the 18.18 in the earlier table, and do not make clear whether the two columns are a repeat of the test or the comparison with the manual test; and for validity the two papers give two different pairs of figures for the same comparison, 0.939 and 0.974 in one, 0.961 and 0.895 in the other, without explaining why. A correlation, moreover, shows that two measurements rise and fall together, not how far off a single test may be, and nobody has calculated the typical error. The studies that used the device afterwards, in 2023 and 2024, come from the same university and quote the 2022 coefficients without a fresh validation.claim:strumento-digitale-tenuta-arco:revision:2026-02-28:2Sat, 28 Feb 2026 08:00:00 GMT https://matteocampagna.com/en/registry/physical-training/instrumented-riser-draw-strengthclaim:strumento-digitale-tenuta-arco:new_claim:2026-02-11:riportatoWed, 11 Feb 2026 08:00:00 GMT