With bows up to 32 pounds the loads on the lower back stay below risk thresholds
2 studies · 28 archers measured
Estimated compression between the fourth and fifth lumbar vertebrae with 20, 25 and 32 pound bows
newtons
The numbers in the figure
| Study or group | Value (newtons) | Interval | n | Stance |
|---|---|---|---|---|
| men, 20 lb | 581 | ± 177.8 (mean ± standard deviation) | 7 | for |
| men, 25 lb | 618.1 | ± 266.5 (mean ± standard deviation) | 7 | for |
| men, 32 lb | 772.8 | ± 261.3 (mean ± standard deviation) | 7 | for |
| women, 20 lb | 511 | ± 97.9 (mean ± standard deviation) | 6 | for |
| women, 25 lb | 554.9 | ± 115.1 (mean ± standard deviation) | 6 | for |
| women, 32 lb | 488.4 | ± 43 (mean ± standard deviation) | 6 | for |
The summary today
There is a single research group on this question, which has published three papers on the same thirteen students from a US university club, shooting barebow recurves of 20, 25 and 32 pounds at ten and fifteen yards. The loads are estimated, not measured: inertial sensors reconstruct posture and ergonomics software calculates compression between the fourth and fifth lumbar vertebrae. The margin is wide: depending on the condition and the paper, compression runs from about 470 to about 890 newtons, against the 3,400 used as a safety limit, and shear forces sit between 18 and 64 newtons against a limit of 700. Going from 20 to 25 pounds changes nothing, while going to 32 raises compression in the men (from 581 to 773 newtons in one paper) but not in the women. Besides draw weight, the archer and the trunk matter: in one paper compression is linked mainly to body mass (r = 0.62), and in all three archers who flex the trunk forward load the lower back more and those who extend it backwards load it less, with a link that grows stronger with the heavier bow. This fits with the screening of fifteen young elite Israeli archers, none of whom had low back pain. There are three limits: one sample, forces calculated by a model and draw weights far from competition ones, so the claim holds for archers shooting light bows at short distances.
Also phrased as: "does archery hurt your back"; "lumbar load in archers"; "draw weight and back pain"; "spinal compression in archery"; "trunk posture and the lower back"
In practice
The usual line is that archery puts no strain on the back, because the draw is done with the shoulders, and that an archer's back pain comes from posture rather than from draw weight.
Evidence
-
2024
For Archers Published later
13 university students with 20 and 25 pound bows, aiming at targets centred 1.0 and 1.4 metres off the ground, at ten yards: estimated L4-L5 compression during the draw ranges from 511 to 558 newtons in the women and from 581 to 665 in the men, against a safety limit of 3,400. Going from 20 to 25 pounds or raising the target does not clearly increase it.
Exploring injury assessment using motion tracking technology and ergonomic tools in archery performance · Xiaoxu Ji, Irati Arzalluz, Xin Gao, Zainab Al Tamimi, Ethan Swierski, Davide Piovesan
-
2024
Context Archers Published later
In the same paper estimated compression is linked mainly to the archer's body mass (r = 0.62) and less to trunk flexion (r = 0.40).
Exploring injury assessment using motion tracking technology and ergonomic tools in archery performance · Xiaoxu Ji, Irati Arzalluz, Xin Gao, Zainab Al Tamimi, Ethan Swierski, Davide Piovesan
-
2024
For Archers Published later
The same thirteen with 25 and 32 pound bows, at ten and fifteen yards, at the instant before release: mean compression between 531 and 576 newtons in the women and between 631 and 891 in the men, the highest with the 32 pound bow at ten yards. Every value stays below 3,400 newtons.
An Ergonomics Analysis of Archers through Motion Tracking to Prevent Injuries and Improve Performance · Xiaoxu Ji, Jenna Miller, Xin Gao, Zainab Al Tamimi, Irati Arzalluz, Davide Piovesan
-
2024
Context Archers Published later
The correlation between compression and trunk flexion rises from 0.30 with the 25 pound bow to 0.45 with the 32. With the 32 pound bow the women lean the trunk back by about 17 degrees against the men's 5 (p = 0.001 and 0.0002).
An Ergonomics Analysis of Archers through Motion Tracking to Prevent Injuries and Improve Performance · Xiaoxu Ji, Jenna Miller, Xin Gao, Zainab Al Tamimi, Irati Arzalluz, Davide Piovesan
-
2025
For Archers Published later
The same thirteen with 20, 25 and 32 pound bows, at release: L4-L5 compression between 469 and 773 newtons depending on sex and condition, against 3,400; anteroposterior shear between 36 and 64 newtons and lateral shear between 18 and 55, against a limit of 700. None of the six combinations comes close to risk values.
The Impact of Draw Weight on Archers’ Posture and Injury Risk Through Motion Capture Analysis · Xiaoxu Ji, Zainab Al Tamimi, Xin Gao, Davide Piovesan
-
2025
Context Archers Published later
From 20 to 32 pounds, at ten yards, compression rises in the men from 581.0 ± 177.8 to 772.8 ± 261.3 newtons and not in the women, who go from 511.0 ± 97.9 to 488.4 ± 43.0.
The Impact of Draw Weight on Archers’ Posture and Injury Risk Through Motion Capture Analysis · Xiaoxu Ji, Zainab Al Tamimi, Xin Gao, Davide Piovesan
-
2025
Context Archers Published later
The further the archer extends the trunk backwards, the lower the estimated compression, and the link grows with draw weight: r = 0.35 with the 20 pound bow, 0.39 with the 25, 0.53 with the 32. In the same way trunk rotation becomes increasingly tied to flexion of the string shoulder, from 0.29 to 0.76.
The Impact of Draw Weight on Archers’ Posture and Injury Risk Through Motion Capture Analysis · Xiaoxu Ji, Zainab Al Tamimi, Xin Gao, Davide Piovesan
-
2025
Context Archers Published later
In the pre-season screening of 15 young elite Israeli archers, mean age 17.2, none report low back pain; two of the fifteen report pain in the thoracic region.
Abdominal and Multifidus Muscle Morphology and Function, Trunk Clinical Tests, and Symmetry in Young Elite Archery Athletes · Gali Dar, Alon Yehiel, Kerith Aginsky, Yossi Blayer, Maya Calé-Benzoor
Status history
- 2024 Reported The question is asked of archers for the first time, and the same group publishes two papers on the same thirteen university students. With inertial sensors and an ergonomic model, estimated L4-L5 compression sits between 511 and 665 newtons with 20 and 25 pound bows and reaches 891 in the men with the 32 pound bow at ten yards, against a safety limit of 3,400. Going from 20 to 25 pounds or raising the target does not push it up, while trunk flexion does, and more so with the heavier bow. Forces calculated rather than measured, one sample: reported.
- 2025 Reported The third paper on the same sample brings the three draw weights together: at release compression stays between 469 and 773 newtons and shear well below 700, it rises in the men from 20 to 32 pounds but not in the women, and it falls in archers who extend the trunk backwards. The same year a screening of fifteen young elite Israeli archers finds no low back pain at all. Sample and tasks are the same, so it is not an independent replication: the status does not rise.
Related
Related articles
- The archer's back: how much draw weight loads it and what the asymmetry of shooting leaves behindHow much a 20 to 32 pound bow loads the lower back, why trunk and body mass matter, and what the studies say about asymmetry in archers' bodies.
- Injuries in archery: where they happen and how to prevent themFew serious injuries, frequent overuse: where archers get hurt, what the studies say about risk, and what can be done to prevent the damage.
Research lines
Cite
Campagna, M. (2026). With bows up to 32 pounds the loads on the lower back stay below risk thresholds (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/health/lower-back-load-draw-weight
@misc{campagna2026_carichilombarilibbraggio,
author = {Campagna, Matteo},
title = {With bows up to 32 pounds the loads on the lower back stay below risk thresholds},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/health/lower-back-load-draw-weight},
note = {Version 1; accessed 2026-10-16}
}
Follow this claim
RSS is an address you paste into a feed reader: each time this claim changes status, adds a year to its history or is revised, a new item appears there.
Registry updates by email
At most one email a month, sent only when something has changed: claims that change status, new claims, Lab predictions registered or resolved, new studies and new books.
Sign-ups are handled by Systeme.io, the service that runs the newsletter. Every email has a link to unsubscribe with one click.
Other claims in this domain
- ReportedA carotenoid and omega-3 supplement improves the archer's sleep1 study · 29 archers measuredStatus since 2026
- ReportedA day of competition does not lower an archer's salivary IgA2 studies · 48 archers measuredStatus since 2021
- ReportedA few nutrition education sessions change how an archer eats and raise blood glucose in competition1 study · 8 archers measuredStatus since 2021
- ReportedA few weeks of breathing exercises improve young archers' respiratory function1 study · 36 archers measuredStatus since 2025
- ReportedA few weeks of shooting alone improve shoulder mobility1 study · 24 archers measuredStatus since 2026