Of the clinical trunk tests, only the side plank is linked to how well an archer activates the deep back muscles
1 study · 15 archers measured
The summary today
A single 2025 study has set the clinical trunk tests against a direct measure of the muscles: 15 young elite Israeli archers, 10 boys and 5 girls with a mean age of 17, assessed before the season with ultrasound and with three holding tests, the side plank on each side and trunk extension. Only the side plank on the non-dominant side goes together with how much the back muscles at L5 thicken from rest to contraction, with r = 0.66 for the muscles on the dominant side and 0.75 for those on the non-dominant side (Spearman correlations). The dominant-side plank and trunk extension are linked to nothing, and none of the three tests says anything about the deep abdominals, transversus abdominis and internal oblique. The result needs care: fifteen people, twenty-four correlations calculated without correction for multiple comparisons, only two of them significant and both on the same test. It is a link between two measurements taken on the same day, and nobody has checked whether training the side plank changes activation or aiming.
Also phrased as: "side plank for archers"; "core tests for archers"; "trunk endurance tests"; "side plank and deep muscles"
In practice
In archers' test batteries the side plank and the trunk extension hold are often used as a measure of the core, on the assumption that whoever holds longer has better control of the deep muscles.
Evidence
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2025
For Archers Published later
15 young elite archers, 10 boys and 5 girls with a mean age of 17: holding time in the non-dominant side plank correlates with the change in thickness of the back muscles at L5 from rest to contraction, r = 0.660 (p = 0.01) on the dominant side and r = 0.751 (p = 0.01) on the non-dominant side; at L4 r = 0.239 (p = 0.43) and r = 0.514 (p = 0.07).
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
-
2025
For Archers Published later
The other two tests are not linked to any ultrasound measure: trunk extension with correlations between -0.168 and 0.278 (p between 0.33 and 0.99), the dominant-side plank between 0.065 and 0.454 (p between 0.12 and 0.83). There are 24 correlations in all, with no correction for multiple comparisons.
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
-
2025
Context Archers Published later
No clinical test tells us anything about the deep abdominals: the correlations of transversus abdominis and internal oblique with the three tests lie between -0.168 and 0.450, all with p of 0.12 or more.
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
-
2025
Context Archers Published later
Reference values: side plank holding time has a median of 92 seconds per side, with quartiles from 62 to 107 on the dominant side and from 60 to 127 on the non-dominant side, and no difference between sides (p = 0.34).
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
-
2025
Context Archers Published later
On ultrasound, on the dominant side, the back muscles go from 3.35 to 4.31 cm at L4 and from 3.07 to 3.83 cm at L5 between rest and contraction, about 29 and 25 per cent more; transversus abdominis from 0.47 to 0.70 cm and internal oblique from 0.84 to 1.07 cm (medians).
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
- 1990 Not studied In the registry's bibliography nobody has yet set the clinical trunk tests against a direct measure of muscle activation in archers: planks and holds are used as a measure of the core without knowing what they actually measure.
- 2025 Reported Fifteen young elite archers are measured with ultrasound and with three clinical tests: holding time in the non-dominant side plank goes together with the ability to thicken the back muscles at L5, while the dominant-side plank and trunk extension are linked to nothing, and no test says anything about the deep abdominals. It is a single cross-sectional study, with many correlations and no correction: evidence in favour, and limited.
Related
Related articles
- 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.
- Balance, core and proprioception: the training you never seeWhat balance and core exercises change in archers, which test is linked to score, and what shoulder position sense does and does not tell you.
Research lines
Cite
Campagna, M. (2026). Of the clinical trunk tests, only the side plank is linked to how well an archer activates the deep back muscles (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/physical-training/trunk-clinical-tests-muscle-activation
@misc{campagna2026_testclinicitroncoattivazione,
author = {Campagna, Matteo},
title = {Of the clinical trunk tests, only the side plank is linked to how well an archer activates the deep back muscles},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/physical-training/trunk-clinical-tests-muscle-activation},
note = {Version 1; accessed 2026-10-16}
}
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