During the draw the load is shared between the rotator cuff and the deltoid, and no muscle comes close to its maximum

The summary today

Nobody has measured it in archers: the only estimate comes from a model. In 2015 a musculoskeletal model, built on motion capture of a single adult archer drawing a 48 lb bow, used inverse dynamics to compute shoulder muscle activity during the draw. Read off the graphs, the peaks are around 15% of maximum voluntary contraction for the infraspinatus, about twice the supraspinatus (around 6%), while the teres minor, which the text puts at the same level as the supraspinatus, sits slightly above it on the graphs, at around 8%; the deltoid reaches around 13%, the trapezius around 8% and the rhomboids stay below 3%. The load, then, is shared between the rotator cuff and the deltoid, which the authors class as an accessory muscle but which in their own model works harder than two of the three cuff muscles, and no muscle goes past a fifth of its maximum. The authors conclude that the cuff works harder than the accessory muscles, but in their graphs this holds for the infraspinatus, not for the supraspinatus and teres minor. A second model, from 2016, of a compound bow with no archer described, finds the drawing-arm forces lowest at the release and the middle trapezius inactive after the set-up. In 2021 a measurement on 15 Polish national team archers and 15 people with no experience reports shoulder moments of a few hundredths of a newton metre per kilogram in both groups, but it does not say which phase or which arm they refer to, does not say which muscles are working, and comes from a journal with questionable editorial standards. These are computed numbers, for a 48 lb bow: they say nothing about competition draw weights or about archers other than the one in the model.

Also phrased as: "shoulder muscles in the draw"; "rotator cuff and archery"; "you draw with your back"; "how hard the shoulder works in the draw"

Evidence

• 2015
  For Model Published later

  Inverse-dynamics musculoskeletal model built on motion capture of a single adult male archer, 48 lb bow. Read off the graphs in figures 6 to 11 (percentage of maximum voluntary contraction), the peaks are around 15% for the infraspinatus, 13% for the deltoid, 8% for teres minor and trapezius, 6% for the supraspinatus and below 3% for the rhomboids; the text gives only the ratios, not the values. The load is shared between the rotator cuff and the deltoid, and no muscle reaches a fifth of its maximum.

  Inverse Dynamic Analysis of Shoulder Muscle Activity During Archery Draw Back · Aviktha Reddy, Yahia M. Al-Smadi

• 2015
  Context Model Published later

  In the same model the infraspinatus works about twice as hard as the supraspinatus, and teres minor and supraspinatus work at the same level. The authors class the deltoid as an accessory muscle and conclude that the rotator cuff works harder than the accessory muscles, but in their graphs the deltoid exceeds the supraspinatus and teres minor.

  Inverse Dynamic Analysis of Shoulder Muscle Activity During Archery Draw Back · Aviktha Reddy, Yahia M. Al-Smadi

• 2016
  Context Model Published later

  Model of the drawing arm with a compound bow, five segments, 12 muscles and 6 joints, optimised with Lagrange multipliers and with no archer described: the release is the phase with the lowest muscle forces of the whole shot, and after the set-up the middle trapezius comes out inactive, with the load passing to the biceps and middle deltoid. The units of the forces are not stated.

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

• 2021
  Context Archers Published later

  15 Polish national team archers and 15 people with no experience: the paper reports shoulder moments when raising and drawing the bow, for example 0.092 Nm/kg in abduction for the experienced archers and 0.085 for the novices, and -0.035 and -0.029 Nm/kg in external rotation, and the authors write that the movement does not call for large moments. It does not say, though, which phase, which arm or which instant these values refer to, and for a shoulder holding a bow at full draw they look very low; nor does it report any statistical test: the figures can be read in the paper but cannot be interpreted. It measures the joint, not individual muscles. Journal with questionable editorial standards.

  Torque Power and Angle Movement of the Shoulder Joint in Archery Questionable venue · Andrzej Kępczyński, Michalina Błażkiewicz

Status history

1. 2015 Transferred The only estimate comes from a musculoskeletal model built on the movement of a single archer with a 48 lb bow: the infraspinatus works about twice as hard as the supraspinatus, the teres minor at the same level as the supraspinatus, and the deltoid, which the authors class as accessory, harder than two of the three cuff muscles, while no muscle goes past a fifth of maximum voluntary contraction. These are computed numbers and nobody has measured them in archers, so transferred.
2. 2016 Transferred A second model, of the drawing arm with a compound bow and no archer described, finds muscle forces lowest at the release and the middle trapezius inactive after the set-up, with the load passing to the biceps and middle deltoid. It does not look at the rotator cuff and measures nothing in archers: the status does not change.
3. 2021 Transferred A measurement in archers arrives, 15 from the Polish national team, alongside 15 people with no experience: it reports shoulder moments when raising and drawing the bow, but does not say which phase or which arm they refer to. It says how hard the joint works, not which muscles carry the load or how close they come to their maximum, and it comes from a journal with questionable editorial standards: it stays as context, and the status stays transferred.

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Research lines

• 63 studiesThe archer's physical profile: strength, endurance and size
• 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