In more experienced archers the transversus abdominis plays a larger part in stabilising the trunk

The summary today

Two cross-sectional studies find that the transversus abdominis carries more weight in more experienced archers. In kyudo, in nine practitioners measured with electromyography of eight trunk muscles, the coordination module working in the second half of the shot loads on the internal oblique and transversus abdominis in the four experts and on the external oblique in the five less experienced archers. Outside kyudo, in twenty-eight Indian archers of three levels, the transversus works at 22.9% of maximal contraction at anchor and 32.9% at release in the elite group, against 7.4 and 12.2% in the beginners, and level weighs far more on the transversus than on the multifidus; the superficial abdominals were not measured there, though, so the comparison with them exists only in kyudo. These are comparisons between groups at a single point in time, with no link to score, and where score is measured the picture gets more complicated: in eight French elite archers, after the release of arrows scoring 8 or less the transversus is more active, not less, than on the 9s and 10s.

Also phrased as: "deep core in archery"; "engage the transversus abdominis while aiming"; "don't brace the abs"; "trunk stability in expert archers"; "hold the trunk with the core"

Evidence

• 2017
  For Kyudo archers Published later

  9 male kyudo practitioners (22 ± 1 years, 7 ± 3 years of practice), 4 experts at level 4 or above in the kyudo proficiency test and 5 at level 3 or below, surface electromyography of 8 trunk muscles broken down into coordination modules: the second module, active in the second half of the shot in both groups, loads mainly on the internal oblique and transversus abdominis in the experts and on the external oblique in the less experienced archers, with a similarity between groups of 0.44 against an equality threshold of 0.75. A pilot study, with no statistical test on the weights.

  Comparison of Modular Control of Trunk Muscle by Japanese Archery Competitive Level: A Pilot Study · Naoto Matsunaga, Atsushi Imai, Koji Kaneoka

• 2017
  Context Kyudo archers Published later

  In the same sample two modules explain more than 90% of the variance in each of the 9 archers, not only in the group average. The first module, carried by the erector spinae and active in the first half of the shot, is the same in both groups (similarity 0.99), and the erectors are also the muscles that vary most from archer to archer; in the experts the first module stays more active in the second half of the shot, but only descriptively. What changes in the second module is the muscles, not the timing of its activation.

  Comparison of Modular Control of Trunk Muscle by Japanese Archery Competitive Level: A Pilot Study · Naoto Matsunaga, Atsushi Imai, Koji Kaneoka

• 2021
  For Archers Published later

  28 Indian male archers, 9 beginners, 10 trained and 9 elite, 10 arrows at 10 m with electromyography of the transversus abdominis and multifidus: in the elite group the transversus rises from 22.90 ± 8.14% of maximal contraction at anchor to 32.85 ± 13.88% at release, in the trained group from 18.54 to 23.89%, in the beginners from 7.42 to 12.15%. The group effect is much stronger on the transversus (partial eta squared 0.563) than on the multifidus (0.271) or the co-contraction index (0.267). The superficial abdominal muscles were not measured.

  EMG Activity of Transversus Abdominis, Multifidus and Co-Contraction Index in Different Phases Amongst Varied Level Archers: A Cross-Sectional Study · Sheikh Azhar, Saurabh Sharma, Shalini Sharma, Tarushi Tanwar

• 2021
  Context Archers Published later

  In the same study anchor is the moment when the core works least at every level, and the only phase transition that really changes activity is the one from anchor to release, for the transversus alone (p = 0.001); the multifidus stays stable across all phases (p = 0.649). Over the ten shots of the series the average level of co-contraction does not change (p = 0.742), but it shifts between phases (interaction p = 0.001).

  EMG Activity of Transversus Abdominis, Multifidus and Co-Contraction Index in Different Phases Amongst Varied Level Archers: A Cross-Sectional Study · Sheikh Azhar, Saurabh Sharma, Shalini Sharma, Tarushi Tanwar

• 2025
  Context Archers Published later

  8 French high-level recurve archers, 4 women and 4 men, 549 arrows at 70 m: in the follow-through the transversus abdominis is more active on arrows scoring 8 or less than on the 9s and 10s, and the external oblique on the string side is less active on the 8-or-less arrows and on the 9s than on the 10s (p < 0.05, values readable only from the figure). It compares arrows from the same archer, not archers of different levels.

  A multi-parameter investigation of elite archery: distinguishing individual and shared performance strategies during the aiming and follow-through phases · Raphaël Jacquot, Khaireddine Ben Mansour, Kévin Bouillet, Jean-Philippe Jehl, Gérôme Gauchard

• 2026
  Context Archers Published later

  The doctoral thesis that contains the 2025 study reports the same 549 arrows from the same 8 archers and counts only once: transversus abdominis more active and string-side external oblique less active in the follow-through of the worst arrows. It adds the forearm of the bow arm, with the finger extensor more active and the superficial flexor less active on low-scoring arrows.

  Analyse multidimensionnelle de la performance en tir à l'arc · Raphaël Jacquot

Status history

1. 2017 Reported The first study to ask the question is on nine kyudo practitioners, measured with electromyography of eight trunk muscles. Two coordination modules are enough to describe every archer: the first, carried by the erector spinae, is identical in experts and less experienced archers; the second, active in the second half of the shot, switches on at the same moment in both groups but loads on the internal oblique and transversus abdominis in the four experts and on the external oblique in the five less experienced ones. It is a single pilot study, cross-sectional and on kyudo alone, which counts as archery but cannot take the claim beyond reported.
2. 2021 Reported The question moves beyond kyudo: twenty-eight Indian archers, nine beginners, ten trained and nine elite, measured on the transversus abdominis and multifidus across the five phases of the shot. Level shows mostly on the transversus, which in the elite group works at 22.9% of maximal contraction at anchor and 32.9% at release against 7.4 and 12.2% in the beginners, with a group effect twice the size of the one on the multifidus. The superficial abdominals were not measured, though, so the comparison with them is still the kyudo one. With two cross-sectional comparisons in favour, the status remains reported.
3. 2025 Reported For the first time the abdominal muscles are set against the score of each arrow, in eight French elite archers and 549 arrows at 70 m, and the result does not go the expected way: in the follow-through of arrows scoring 8 or less the transversus abdominis is more active than on the 9s and 10s, while the external oblique on the string side is less active. It compares arrows rather than archers, so it does not change the count, but it shows that more transversus does not automatically mean a better shot. The status remains reported.

Related

Related articles

• Muscle synergies in archery: the motor patterns of elite archersMuscle synergies in archery: what changes between elite and novice archers, and what happens on the best arrows, at the clicker and at the release.
• Experts and beginners: what really changes in the shotWhat an expert archer does that a beginner does not: consistency, muscles, balance, timing and years of practice, and how far the studies support each.
• Posture and stability in archery: what biomechanists revealCentre of pressure, bow movement while aiming, balance before and after the release, the trunk and balance tests: what the biomechanics of stability measures and how much it weighs on the score.

Research lines

• 46 studiesShooting EMG from 1971 to today
• 54 studiesMovement variability and individual technique since 1971

Other claims in this domain

• CorroboratedBetween one and a half and two tenths of a second pass between the clicker sounding and the arrow leaving7 studies · 94 archers measuredStatus since 1990
• ReportedA camera diagonally behind the archer measures the vertical sway of the aim well, but not the horizontal1 study · 3 archers measuredStatus since 2010
• ReportedA continuous final pull through the clicker leads to better shots9 studies · 56 archers measuredStatus since 1993
• ReportedA sound or light cue about the angle of the bow arm tightens beginners' groups2 studies · 1 archers measuredStatus since 2012
• ReportedA thumb grip on the string is less tiring than a finger grip3 studies · 9 archers measuredStatus since 1990

See all claims on technique and biomechanics