Shoulder kinesio tape and archery: Rajabzadeh 2019

Thirty female recurve archers from clubs in Tehran shot three arrows at 18, 30 and 50 metres, received elastic tape over the supraspinatus and deltoid of the drawing shoulder, and repeated the same tests half an hour later. They averaged 24.8 years of age, from 18 to 39, and had at least a year of practice behind them.

After taping, the median scores over the three arrows rose at all three distances: from 26 to 28 at 18 metres, from 23 to 27 at 30 metres and from 23 to 26 at 50 metres, out of a maximum of 30 (p = 0.004, p below 0.001 and p = 0.004). The minimum scores rose in the same way, from 22 to 24, from 17 to 23 and from 17 to 22.

The other measure was shoulder position sense, tested by asking each archer, lying down with her eyes shut, to reproduce two angles of external rotation. At 60 degrees the mean error went from minus 5.91 degrees to minus 0.99, a mean difference of 4.92 degrees (p below 0.001): before taping the archers tended to stop well short of the required angle, and afterwards they arrived almost on it. At 30 degrees nothing changed, 0.60 against 0.23 degrees (p = 0.637), and the authors connect the difference to the fact that shoulder rotation at full draw sits closer to 60 degrees than to 30. The spread narrowed considerably along with the error: the standard deviation at 60 degrees fell from 6.52 to 3.70 degrees.

This is a quasi-experimental intervention study: a single group measured before and after, with no control group and no sham tape. The participants came from three clubs in Tehran and took part voluntarily. Inclusion required no pain in the tested shoulder, at least six hours of training a week, at least a year of archery and an age between 18 and 40; archers were excluded if they had injured another joint of the upper limb in the previous six months, had surgery on the shoulder or shoulder blade, had forward head or rounded shoulder posture, felt pain during the test, showed muscle weakness on manual testing or had restricted range of motion.

The position sense test is done lying supine on a bed. An inclinometer is fixed to a wristband, with the shoulder at 90 degrees of abduction, the elbow at 90 degrees of flexion and rotation at zero. With the eyes shut, the examiner takes the arm to 30 degrees of external rotation and holds it for five seconds, then returns it; after fifteen seconds' rest the archer tries to find the position again on her own, three times, and the mean is used. The same is then repeated at 60 degrees. Shooting was three arrows per distance, scored under federation rules.

The taping uses three strips of sports tape at 10 to 15% tension, applied with the Kase technique: an I-shaped strip over the supraspinatus, anchored five centimetres below the greater tuberosity of the humerus with its tail above the scapular spine; a Y-shaped strip over the deltoid, with the two arms along its anterior and posterior borders; and a third I-shaped strip running from the coracoid process down below the scapular spine to hold the first two in place. Thirty minutes after application the repositioning test and the shooting were repeated, with half an hour of rest between the first shooting test and the later ones to limit the effect of fatigue. Scores were compared with the Wilcoxon test and repositioning errors with the paired t-test.

The design does not allow what was observed to be attributed to the tape. There is no control group, no sham tape, nobody was blinded to anything and the second test always comes after the first: thirty minutes and three arrows per distance separate the two shooting sessions, so warming up, getting used to the range and the athlete's own expectation all push in the same direction as the measured effect. A median improvement from 23 to 27 points over three arrows at 30 metres is large, which is one more reason not to take it as the size of the effect of a strip of tape.

The scores rest on three arrows per distance, too small a sample of shots to represent a performance: a single stray arrow moves the median. The paper states that all the athletes shot with the same bow and the same technique, which is unusual in a group of thirty club archers, and it does not explain how the differences in draw length and draw weight were handled.

The proprioceptive measure has two problems of its own. The first is its name: the table calls it absolute error, but the values are negative and run from minus 18.10 to plus 7.47 degrees, so it is a signed error, that is a tendency to stop short of or beyond the angle, not the size of the deviation. The second is the position: the test is done lying down while an archer shoots standing, and the authors themselves say it should be repeated seated or standing. The baseline table contains other incongruous numbers, such as a mean stature of 1.60 metres with a standard deviation of 7.34 and a mean internal rotation of 78.60 degrees with a minimum of 75 and a maximum of 98.

For an archer, what the study actually shows is narrower than its title suggests: thirty club archers, measured twice in the same afternoon, scored more on the second test and found the 60-degree external rotation angle of the drawing shoulder more accurately. Elastic tape was applied between the two tests, but since there was no comparison and none of the usual safeguards for separating the effect of the tape from the effect of having already shot, the number of points gained does not tell us what the taping is worth.

The underlying idea remains of interest to an archer: the 60 degrees used in the test is close to the external rotation of the string shoulder at full draw, while the 30 degrees, where nothing changed, sits at the start of the movement. If taping does affect position sense, the study suggests where to look for it. The literature the authors cite shows how unsettled the field is: in one study of handball throwing, taping increased speed and reduced accuracy; in another it impaired shoulder position sense at 90 degrees of elevation; and in one on archers it worked only after four weeks of tape on the bow-arm deltoid. None of this evidence is firm enough to support practical guidance, and here there is no follow-up at all: the archers were measured once, thirty minutes after application.