Balance and body measures in archers: Patil 2019 study

The study measures balance in 93 Indian archers (51 men and 42 women, aged 16 to 25, mean age 19.45) and in 101 non-archers of similar age (51 men and 50 women, mean age 20.67), and relates it to a few body measurements. The archers did better on the Star Excursion Balance Test, in which the person stands on one leg and reaches with the other in eight directions: on the right leg, for example, the summed distance was 684.38 cm in male archers against 550.4 in male controls, and 661.61 against 573.98 in women. On the one-leg standing test, the female archers lasted longer (169.1 seconds on the left and 187.06 on the right) than the male archers (147.64 and 152.90), with very large standard deviations, around 100 seconds in the men.

Taking all the archers together, those with a thicker triceps skinfold stayed balanced on one leg for less time (r = -0.221 on the left and -0.401 on the right), and heavier archers reached a slightly higher sum on the Star Excursion test (r = 0.289 and 0.266). In the men, one-leg balance rose with height and fell with triceps skinfold and, on the right leg, with body mass index; in the women the only significant link was between right-leg balance and biceps skinfold (r = -0.318).

Data were collected between June and October 2018 at several archery academies in Mumbai, in the morning between 8 and 12. Height was taken with a stadiometer, weight with digital scales, and biceps and triceps skinfolds with a Harpenden caliper on the right side, each measured three times with the median kept. Body fat percentage was not measured: it was calculated from body mass index with a separate formula for men and women.

In the static balance test the person held a one-leg stance for as long as they could, after a minute's practice, and the best of three attempts was kept; timing stopped when the raised foot touched the floor or the person hopped. In the Star Excursion test the subject stood on one leg in the middle of a grid of eight tapes set 45 degrees apart and touched the furthest point they could reach in each direction with the other foot; the result is the sum of the distances, in centimetres, for each leg. Groups were compared with one-way analysis of variance and relationships with Pearson correlations.

The journal is flagged in the registry as a venue with questionable editorial standards, and the text has several inconsistencies. The title refers to inter-university players, the text to Indian national-level archers recruited from academies in Mumbai, without saying what bow they shot or what competitions they took part in. The abstract calls the correlations with body weight negative, but in the table they are positive, as the discussion acknowledges; the conclusion credits one-leg balance with links to body mass index, skinfolds and body fat that do not appear in the pooled group; and the abstract and results disagree on which group differences were significant. Because body fat percentage is derived from body mass index, the two rows in the tables are almost identical and should not be counted as two findings.

The Star Excursion sum is not normalised to leg length, so people with longer legs start with an advantage, which may also explain the correlation with body weight. Many correlations were calculated, with no correction for multiple comparisons, and nearly all are weak. Above all, the study measures nothing about shooting, neither score nor aiming steadiness: the fact that the archers had better balance than the controls does not say whether shooting improved it or whether balance helps shooting.

For archers the study says little. It shows that in this group the Mumbai archers reached further than non-archers of the same age on a dynamic balance test, and that those with more fat on the back of the arm generally lasted less time on one leg. These are weak associations, measured on a single occasion with no link to score or to steadiness on the shooting line, so they do not support the idea that working on balance or body composition improves shooting.

The authors conclude that the data can help with talent selection and core training; that is their suggestion, and the study does not test it. A measure of balance that relates to shooting needs studies that record body sway during aiming, not one-leg tests on the floor.