Elite archers' aiming and follow-through: Jacquot 2025

Eight top-level French archers shot 72 arrows at 70 metres wearing fourteen channels of electromyography, standing on a force plate, with inertial sensors on the drawing arm and a chest belt, while two cameras filmed the movement and the clicker. There were four women and four men, mean age 19.1, all ranked in the top twenty of the 2024 French Olympic recurve ranking at 70 metres, with a mean best score of 654.62 out of 720 and around 21 hours of training a week. The 549 arrows left after discards for sensor problems were divided into three groups: 10, 9, and 8 or below.

The question is not which technique is right, but which parameters separate the good arrows from the rest across the whole group and which do so only within one archer at a time. At group level, during aiming, seven muscles, three postural measures and clicker reaction time were associated with the score. The posterior deltoid and middle trapezius on the drawing side were more active on the poorer arrows, as was the extensor digitorum on the bow side; conversely the extensor and the flexor digitorum superficialis on the drawing side, the flexor on the bow side and the multifidus on the drawing side were less active on the poorer arrows. The centre of pressure moved faster on the poorer arrows, both overall and along the shooting axis, and the interval between the clicker falling and the release was longer.

In the follow-through, after the release, the group-level differences involved four muscles and three postural measures: the extensor digitorum on the bow side and the transversus abdominis were more active on the poorer arrows, the flexor digitorum superficialis on the bow side and the external oblique on the drawing side less active; the range of centre-of-pressure movement perpendicular to the shot and its peak velocity were greater on the poorer arrows, while the range along the shooting axis was wider on the 10s than on the 9s. Shoulder and elbow angles on the drawing arm did not change with the score in either phase.

The remaining parameters, those that said nothing at group level, were then examined archer by archer, and there the picture breaks up. The middle deltoid on the bow side was less active on the good arrows in three archers out of eight, the upper trapezius on the drawing side during follow-through in three, the external oblique in two, and six muscles in one archer each. Aiming duration mattered for two archers, and in opposite directions: in the eighth, 10s had a median aiming time of 3.7 seconds against 2.0 for the arrows scoring 8 or less, while in the first, 9s lasted 1.6 seconds against 2.2 for the poorest arrows. Clicker reaction time, by contrast, showed no difference within any single archer.

The recordings were made on an outdoor shooting field, with the archers inside a cabin with open windows and official 122 cm faces at 70 metres. After a fifteen-minute warm-up following their usual routine, each archer shot eight ends of nine arrows with their own bow and arrows, at their habitual pace, with only the time needed to collect the arrows between ends.

Wireless surface electromyography sampled fourteen muscles at 2,000 Hz: on the drawing side the extensor digitorum, flexor digitorum superficialis, middle and posterior deltoid, middle and upper trapezius; on the bow side the flexor digitorum superficialis, extensor digitorum and middle deltoid; and five trunk muscles, the transversus abdominis, the multifidus on both sides and the external oblique on both sides. The skin was shaved, abraded and cleaned to below 5 kΩ impedance, and the electrodes were placed by a single researcher. Before the first end, each muscle underwent a maximal isometric voluntary contraction with a protocol described position by position, and all signals were then expressed as a percentage of that value, after a 20-500 Hz band-pass filter, rectification and averaging over the duration of each phase.

The centre of pressure came from a force plate sampling at 1,000 Hz, with the axis they call mediolateral aligned with the shooting direction and the feet kept still; from it they computed mean velocity overall and along each axis, peak velocity, range along each axis and the surface of the displacement. Two inertial sensors at 200 Hz, one on the forearm and one at the seventh cervical vertebra, gave shoulder abduction and elbow flexion on the drawing side. A chest belt at 32 Hz measured chest excursion. Two GoPro cameras at 240 frames per second served to identify the phases and to measure the interval between the clicker falling and the release, using the video analysis software Kinovea.

The analysis has two steps. First a comparison of the three score groups across the whole sample, with Kruskal-Wallis tests and Wilcoxon pairwise comparisons corrected with Bonferroni, at p < 0.05. Then, on the parameters that had shown no group-level difference, the same comparison repeated within each archer. Parameters significant at group level were excluded from the individual analysis, by the authors' stated choice, since they were taken to represent the shared behaviour already.

There are eight archers, and the authors put this first among the limitations: the sample is small and the results should be read with caution. All eight, moreover, are coached by the same person, which may have produced shared habits and, they add, may also have concealed individual strategies that would have shown up in a more varied group. Fatigue over the 72 arrows was not measured, although it affects both electromyography and postural control. The inertial system had been validated, the electromyography and the force plate had not: the authors say so and recommend device-specific validation in future work.

The design is cross-sectional and compares arrows, not archers over time: it says which parameters accompany a 10 in that session, not that changing them produces a 10. The effect sizes reported in the individual tables are small, between 0.06 and 0.22, and the number of comparisons is large: twenty-six parameters at group level, then eighteen repeated within each of the eight archers. The Bonferroni correction is applied to the pairwise comparisons after a significant test, not across the set of parameters, so some of the individual results may come from the number of tests run.

In several places the text describes as differences values that sit above the stated threshold of 0.05: p = 0.052 for a flexor, 0.054 and 0.058 for a trapezius and a deltoid, 0.068 for one archer's centre-of-pressure velocity. Two muscle names do not match: in two passages the results speak of the "extensor digitorum superficialis", which does not exist, where the list of muscles shows the extensor digitorum is meant. The group-level clicker reaction time values appear only in a figure, with no numbers in the text.

The sample consists of eight top archers and the comparison is between their good arrows and their less good arrows: there is no lower-level group, and the differences the authors find against the literature on experts versus beginners remain their own hypotheses about why. The study shares data with the same author's doctoral thesis, which adds seven regional-level archers; in the registry the two count once.

The study is interesting above all for how it is built: it separates what holds for all eight archers from what holds for one alone, and the second group is not small. At group level, clicker reaction time holds up, shorter on the 10s, as does centre-of-pressure velocity during aiming, lower on the good arrows; in the follow-through, instability along the shooting axis and peaks of velocity go with the poorer arrows. Shoulder and elbow angles on the drawing arm, by contrast, distinguish nothing: in these archers the difference between a 10 and an 8 does not show up in the position of the arm.

Aiming duration is the clearest case of a personal parameter. In archer number eight the 10s had a median aiming time of 3.7 seconds against 2.0 for the poorest arrows; in archer number one the direction was reversed. Two archers from the same group, coached by the same person, with opposite rules: anyone looking here for a correct aiming time in the abstract will not find one. The same goes for the middle deltoid on the bow side, less active on the good arrows in three archers out of eight and indifferent in the other five.

One point concerns how a measurement taken on oneself is read. The comparisons are between arrows from the same archer in the same session, so what emerges is a personal regularity rather than a prescription: an archer who discovered they shoot better with longer aiming would know something about themselves, not something that holds for the person on the next peg. The authors themselves, in their applications section, suggest building a shared foundation first and then adapting it by observing each archer's motor strategy; that is their reading, not a measured result, since no training was tested in this study.