Wheelchair archers' fitness: Erten 2021 study

Eighteen wheelchair athletes from two clubs in Istanbul, nine Paralympic archers and nine premier league basketball players, were compared on strength, shoulder flexibility, reaction time and trunk balance. The basketball players had higher values on almost everything to do with strength. In all six muscle groups measured with the hand-held myometer the difference was large, with p reported as 0.000: shoulder flexors 30.5 on the right and 31.5 on the left against 11.7 and 11.2, extensors 25.4 and 26.0 against 12.7 and 11.6, abductors 26.9 and 27.7 against 9.5 and 8.3, internal rotators 24.6 and 23.1 against 12.1 and 12.5, external rotators 21.6 and 21.2 against 6.8 and 7.0, elbow flexors 31.8 and 31.8 against 15.0 and 12.9, which is to say two to three times as much. For grip strength the difference was significant on the left (48.3 against 28.7 kg, p = 0.030) and not on the right (47.5 against 33.1, p = 0.171). In the reach tests the basketball players went further on the lateral reach (p = 0.015 right and 0.021 left) and the unilateral reach (44.8 against 30.8 cm, p = 0.031), while the bilateral reach did not separate the groups.

Shoulder flexibility and reaction time did not differ, which the authors flag as unexpected between two such different disciplines. The two teams were similar in age, height, weight and body mass index, but not in sporting history: the basketball players had 14.1 years of practice against 4.2 and 27 years of disability against 15.4, while the archers reported about three times the weekly training hours, 28.7 against 8.7. Above all, the two groups did not share the same conditions: among the archers were three athletes with tetraplegia from C7-C8 lesions, four with paraplegia and two with spina bifida; among the basketball players there was no tetraplegia, but five amputees, two cases of polio and two paraplegias at T5 and T7.

The measurements were taken between 20 and 29 April 2019 at the venues where the two teams train. Ten athletes per group had been recruited; one from each dropped out with an upper limb injury, and the study closed with 18 participants. Every measurement except reaction time was repeated three times for each limb and averaged.

Grip strength was measured with a Jamar hydraulic dynamometer at the second handle position. Shoulder flexibility was assessed with the back scratch test, the distance between the fingers of the two hands brought behind the back, one from above and one from below. Reaction time used the Nelson visual hand reaction test, twenty trials from which the five highest and five lowest values were discarded, with the mean of the remaining ten. The strength of the shoulder flexors, extensors, abductors, internal and external rotators and of the elbow flexors was measured with a hand-held myometer. Trunk balance used the modified functional reach test in three versions, unilateral, bilateral and lateral reach, which measures how far a seated athlete can take the hands without support. The data were not normally distributed and comparisons were made with the Mann-Whitney test.

The main limit is the comparison itself, and the authors say so in their conclusions: the two groups were not homogeneous in type of disability, so the differences cannot be attributed to the two disciplines. Three of the nine archers had tetraplegia from a C7-C8 lesion, which reduces grip and trunk control, and the basketball group had no tetraplegia at all; five of the nine basketball players were amputees, with trunk and upper limbs intact. With nine people per group, three athletes move a mean.

The other baseline differences point the same way. The basketball players had more than three times the years of practice and belonged to a premier league team. No variable was adjusted for, and there are around twenty comparisons with no correction.

In the strength tables the p value is reported once for each right-left pair, and the unit of the myometer readings is not stated. There is also an internal contradiction: the article's abstract says the significant grip difference is on the right hand and not the left, while the results section and the table say the opposite. This record follows the table. Nothing about shooting was measured: no score, no functional classification, no information on the bows used.

The study is about wheelchair archery and a comparison with another Paralympic discipline, not about how archers perform. What the figures show first is the make-up of the two groups: in this sample the archers were the athletes whose conditions most involve the trunk and the hands, and the strength values follow that distribution more than they follow the type of training.

One reading does survive: in nine wheelchair archers, shoulder strength measured with the myometer was low in absolute terms, between 7 and 15 depending on the muscle group, alongside the higher weekly training hours of the two teams. That says nothing about whether such strength is enough to shoot well, since no score was recorded, and nothing about what training it would change. For anyone working with wheelchair athletes the paper serves mainly as a methodological reminder: in a sport where functional classification exists precisely because conditions change what a body can do, a comparison between groups that ignores it says little.