While aiming, the posterior deltoid and the middle trapezius are among the hardest-working shoulder muscles

The summary today

Two samples from 2024 point to these two muscles, but neither is a recurve sample. In 24 Malaysian compound archers the posterior deltoid and the middle trapezius on the string side are the muscles in which most archers hold a sustained contraction during the shot, 74.6 and 68.6 per cent of the archers according to the authors, and the middle deltoid is the least active; in 20 Polish traditional archers measured while aiming the posterior deltoid gives the largest signal. The limits are concrete: the Polish study compares different muscles in microvolts, without normalising them, and the Malaysian one measures the whole shot rather than the aim alone, and on average finds the anconeus of the bow arm the most active in the elite and junior groups. For elite recurve the measurements are few and small: in eight French archers, in the three for whom the value is reported, the bow-arm middle deltoid works at between 46 and 66 per cent of maximum contraction while aiming, and on the worse arrows the string-side posterior deltoid and middle trapezius are more active, not less. That these two muscles are among the hardest-working is documented; that they do most of the work on their own, and that more work is better, is not.

Also phrased as: "aiming with the back"; "muscles working while aiming"; "posterior deltoid in archery"; "middle trapezius and shoulder blade"; "which muscles hold the draw"

Evidence

• 2016
  Context Model Published later

  A mathematical model of a compound archer's upper limb, twelve muscles and six joints, with forces estimated by minimising muscle stress: in the bow arm the largest force falls on the middle trapezius, from 4,118 at preparation to 6,176 while aiming and 7,882 at release, followed by the triceps (between 954 and 1,310), while the middle deltoid and the brachioradialis stay at zero in every phase. In the drawing arm, according to the authors, the middle trapezius works only during preparation and then stops, because the compound's pulleys carry the load. The posterior deltoid is not in the model, the units are not stated and some forces come out negative, which the model itself rules out: this is context, not evidence.

  Optimization of upper extremity muscles using compound bow via Lagrange multiplier method (LMM) · Muhammad Shahimi Ariffin, Azmin Sham Rambely

• 2022
  Context Review Published later

  Systematic review of 41 studies on performance assessment: it reports that elite archers actively engage the posterior deltoid and middle trapezius up to full draw, while intermediate archers and beginners rely on the lower trapezius and pull the shoulder blade down, with a less stable arm. These are findings of cited studies, without figures, and they concern the draw more than the aim.

  Performance assessment in archery: a systematic review · Eleonora Vendrame, Valeria Belluscio, Luigi Truppa, Lorenzo Rum, Aldo Lazich, Elena Bergamini, Andrea Mannini

• 2024
  For Archers Published later

  24 compound archers from a Malaysian state squad, aged 14 to 22, surface electromyography as a percentage of maximum contraction over 9 arrows at 18 metres: the string-side posterior deltoid and middle trapezius are the muscles in which most archers hold a sustained contraction during the shot, 74.6 and 68.6 per cent, against 55.9 for the anconeus and 49.6 for the lower trapezius. Out of 24 archers these percentages do not match a whole number of people, and the paper does not say how they were calculated.

  Shoulder Girdle Muscles Activation of Compound Archers · Fatin Nurfatehah Mat Salleh, Mon Redee Sut Txi

• 2024
  Context Archers Published later

  In the same study, the mean values across the three levels: posterior deltoid between 23.4 and 27.1 per cent of maximum contraction, middle trapezius between 24.4 and 32.0, lower trapezius between 15.6 and 27.3, triceps between 17.4 and 20.6, anconeus between 25.1 and 35.6, middle deltoid between 15.2 and 18.9. The middle deltoid is the least active in every group; the most active on average is the bow-arm anconeus in the elite and juniors and the posterior deltoid only in the intermediates, and no difference between levels is significant. The measurements cover the whole shot, not the aim alone.

  Shoulder Girdle Muscles Activation of Compound Archers · Fatin Nurfatehah Mat Salleh, Mon Redee Sut Txi

• 2024
  For Archers Published later

  20 adult Polish traditional archers, electromyography while aiming at baseline and after 50 and 100 arrows: the posterior deltoid gives the largest signal, from 288.5 to 419.8 microvolts depending on group and time point, followed by the middle deltoid (151.8 to 276.7), middle trapezius (129.7 to 227.0), upper trapezius (115.7 to 200.4) and infraspinatus (108.7 to 186.4). These are raw amplitudes, not normalised to maximum contraction, and across different muscles they say little about how hard each one works.

  Analyzing the Impact of Accumulated Training Shots on Electromyography Parameters in Trained Archery Athletes: Exploring Fatigue and Its Association with Training Practices · Weronika Naderza, Bartłomiej Niespodziński, Rafał Studnicki

• 2025
  Context Archers Published later

  8 elite French recurve archers, 549 arrows at 70 metres: while aiming, in the three archers for whom the value is reported, the bow-arm middle deltoid works at between 46.5 and 65.5 per cent of maximum contraction, and in one of them the string-arm middle deltoid at between 31.8 and 35.1. The table only lists muscles that differ between arrows, so it gives no aiming values for the posterior deltoid and middle trapezius and allows no ranking.

  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

• 2025
  Context Archers Published later

  In the same sample, at group level, the string-side posterior deltoid and middle trapezius are more active while aiming on arrows scoring 8 or less than on 10s, with no difference between 8 or less and 9. The authors note that this runs opposite to the comparisons between beginners and elite, where more activity in these muscles goes with the higher level.

  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

• 2025
  Context Archers Published later

  5 elite Russian recurve archers, electromyography of 18 muscles on each side synchronised with the clicker: the asymmetry coefficient of the middle deltoid goes from -0.20 during the draw, favouring the bow side, to 0.09 at the clicker, 0.10 at the release and 0.22 in the follow-through, favouring the string side. The middle deltoid works, but it changes side over the course of the shot. Regional journal.

  Manifestation of asymmetry in muscle activity during the execution of shots from a recurve bow · A.M. Pukhov

Status history

1. 2016 Not studied The first figure on how hard the shoulder muscles work in the shot comes from a mathematical model of a compound archer, with no participants: in the bow arm the largest force falls on the middle trapezius, while in the drawing arm, according to the authors, the middle trapezius stops working after preparation because the pulleys carry the load. The posterior deltoid is not in the model and the units are not stated. Nobody has yet measured on archers which muscles work hardest while aiming: the question remains unstudied.
2. 2022 Not studied A systematic review reports that elite archers actively engage the posterior deltoid and middle trapezius up to full draw, while less experienced archers rely on the lower trapezius and pull the shoulder blade down. It is second-hand, about the draw rather than the aim, and without figures: no study of archers in the registry has yet ranked the shoulder muscles by how hard they work while aiming.
3. 2024 Reported Two independent samples arrive in the same year. In 24 Malaysian compound archers the shoulder girdle muscles work at between 15 and 36 per cent of maximum contraction, the middle deltoid is the least active, and the sustained contraction during the shot involves the posterior deltoid and middle trapezius in most archers; in 20 Polish traditional archers measured while aiming the posterior deltoid gives the largest signal and the infraspinatus the smallest. The status reaches reported and no higher: the measurements are descriptive, one is not normalised, the other covers the whole shot, and in the Malaysian sample the most active muscle on average changes with level.
4. 2025 Reported The first measurements on elite recurve arrive. In eight French archers, in the three for whom the value is reported, the bow-arm middle deltoid works at between 46 and 66 per cent of maximum contraction while aiming, above every mean in the 2024 Malaysian sample, and on the worse arrows the string-side posterior deltoid and middle trapezius are more active than on the 10s. In five elite Russian archers the middle deltoid shifts from the bow side to the string side over the course of the shot. The status remains reported, because neither study ranks the muscles, but they are a reminder that other shoulder muscles also work hard while aiming, starting with the bow-arm middle deltoid.

Related

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Research lines

• 46 studiesShooting EMG from 1971 to today
• 48 studiesWhat predicts the score, and how talent selection tried to use it

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