Bone and muscle in young archers: Goh 2024 study

The study compares 33 Malaysian boys aged 13 to 18 (mean age 15.1): 11 archers, 11 badminton players and 11 peers who did no structured sport. For each of them the authors measured body composition, the speed of sound through the bone of the arm and leg (an indirect index of bone health) and shoulder and knee strength and power on an isokinetic dynamometer.

The archers were heavier than the non-athletes (67.5 kg against 50.7) and had more fat-free mass (49.4 kg against 40.9), with body fat of 24.3% against 16.8%, a difference that was not significant. Bone showed no differences between the three groups. At the shoulder the archers did not differ significantly from the non-athletes on any of the twelve measures; the only shoulder difference involved badminton (average power in extension at 180°/s). At the knee, archers and badminton players outscored the non-athletes on some measures: in the archers average flexion power was 96.51 W against 64.53 at 180°/s and 113.96 against 78.33 at 300°/s, and in extension at 180°/s peak torque was 84.23 Nm against 60.07 and average power 171.66 W against 115.72. In the archers height correlated with peak shoulder flexion torque at 180°/s (r = 0.626) and peak knee extension torque at 60°/s (r = 0.606).

Archers and badminton players had to have practised for at least three years, train at least three times a week and have represented their state in competition; the non-athletes could not be in formal training and had to exercise fewer than three times a week. The sample, all boys from the state of Kelantan, had been calculated at 10 per group plus an allowance for dropouts.

Body composition was measured with a Tanita TBF-140 bioimpedance analyser; bone with an ultrasound sonometer at the distal radius and mid-shaft tibia on the dominant side; strength and power with a Biodex System 3 Pro dynamometer, in shoulder and knee flexion and extension at 60, 180 and 300 degrees per second, again on the dominant side. Groups were compared with analysis of variance and Bonferroni tests, and the links between measures with Pearson correlations within each group of athletes.

With 11 boys per group and dozens of comparisons, some significant differences may appear by chance. Above all, the archers were on average 17 kg heavier than the non-athletes, and strength and power are reported in absolute terms, not relative to body weight: part of the knee difference may simply reflect a bigger body. The study is cross-sectional, so the conclusion that archery and badminton may increase strength and power goes beyond what the data allow; and in boys who are still growing, age and maturation weigh heavily on these measures.

For an archer the dominant side is not necessarily the bow arm or the string arm, and the paper does not specify which it was. Discipline, bow type, draw weight, scores and training volume are not reported. In the discussion the shoulder finding for the badminton players is supported with a study of high-level archers, whereas in this sample the archers show no shoulder difference.

For anyone who shoots, the study says little. In these Malaysian boys the shoulder, the area one would expect shooting to train most, was neither stronger nor more powerful than in peers who did no sport on the isokinetic measures; the differences showed up at the knee, in archers who were also much heavier. Nothing was measured on the shot, and no difference emerged in bone.

It does not follow that archery builds leg strength, or that it neglects shoulder strength: with this design and this sample, all that can be said is that, at around 15, a group of state-level archers did not differ from non-athletes in shoulder strength measured this way.