Rotator cuff in archers: Safari Zanjani 2022 study

Thirty male Iranian archers aged 18 to 24 were split into two groups of 15: one did six weeks of core stability exercises, the other carried on without them. At the end, the training group had more internal rotator strength at the shoulder and a better score on the Upper Quarter Y Balance Test, in which the athlete holds a push-up position and reaches with the free hand in three directions.

Few numbers are published. For internal rotator strength the paper gives only mean differences: in the training group it rose by 2.56 kg between the first and second test (p=0.001), while in the controls it fell by 0.25 kg (p=0.483); at the end of the programme the difference between the groups was 2.425 kg (p=0.001), having not been significant at the start. On the balance test the change within the training group was significant (p=0.001) and within the controls it was not (p=0.054); for the comparison between groups after the programme the authors report p=0.022. The starting and final means appear only in the charts, not in the tables.

The authors describe the study as quasi-experimental: the 30 archers, all men who had trained three times a week under a coach over the previous year, were picked by convenience and then split at random into two groups. The programme lasted six weeks, with three one-hour sessions a week supervised by the examiner: a 10-minute warm-up followed by six isometric trunk exercises, namely side plank, full plank, bird dog, diagonal crunch, abdominal bridge and an exercise the table calls hand-heel. Each exercise was done in 5 sets, with holds starting at 8 to 12 seconds and reaching 14 to 20 seconds in the final week, and with harder variations as the weeks went on (hands instead of elbows, one leg raised, opposite arm and leg, heels on a step). The control group followed no programme over the same period.

Before and after the six weeks, the strength of the shoulder girdle muscles was measured with a handheld dynamometer and shoulder motor function with the Upper Quarter Y Balance Test. The groups were compared with paired and independent t-tests. The paper comes from the second author's thesis at Islamic Azad University, Zanjan.

The design has more than one weakness. The paper does not say how strength was measured: which arm, in what position, with how many attempts; the abstract even refers to the strength of the lumbar muscles, while the tables and figures concern the shoulder's internal rotators. The control group did nothing at all, so the effect of the trunk exercises cannot be separated from that of three extra hours of supervised training a week, and nothing suggests the assessors were unaware of who was in which group.

The numbers do not always add up either. For the final comparison on the balance test the table reports t=1.710 with 28 degrees of freedom and p=0.022, yet with those values a two-tailed p is around 0.10. The participant table gives a mean body mass index of 66, which looks more like a weight in kilograms, and the inclusion criteria contain lines that make no sense for an all-male sample, such as one about the last trimester of pregnancy.

The type of bow is not stated and nothing about shooting was measured: no score, no group size, no aiming stability. The authors acknowledge that diet, sleep and activity outside the programme were not controlled. Their conclusion, that archers should add these exercises to their conditioning, goes beyond what the data show.

For anyone who shoots, this study says little. Six weeks of planks and their variations coincided with more internal rotator strength at the shoulder and a better score on a balance test performed on the arms, in young archers below elite level. What that means for shooting was not measured: nobody looked at scores, holding on aim or shoulder pain, and a stronger internal rotator is not in itself a proven advantage for an archer.

Core work remains a common part of physical preparation, and nothing here argues against it. With a control group that did no training, incomplete numbers and a statistic that does not add up at one point, though, the study is not enough to say that these exercises improve an archer's shoulder, let alone that they prevent injury.