48 This ratio changes with increasing or decreasing UV values: e.g., on the positive UV wrist ratio is 69:31 while on the negative UV the

ratio is 94:6.49 However, Rikli et al.50 demonstrated that the BIBW2992 molecular weight forces transmitted across the ulnar side of the radioulnacarpal joint were much higher than previously stated (the load percentage in neutral wrist position had a relative distribution of 35/55 between radius and ulna). This discrepancy in results may be due to the methodology used and, consequently, to static or dynamic forms of load distribution, but might also be related to age, individual activities, and/or the non differentiation of UV categories. It is common knowledge that supports of the upper limb in all gymnastics apparatus are performed, mostly, with extended wrists, both with the forearm in neutral or prone or

supine position, and/or with wrist deviations (radial or ulnar deviation). According to the results from Rikli et al.50 the relative distribution of forces was localized more ulnarly, and, hypothetically, may predispose gymnasts to wrist pain due to the load-bearing. Mandelbaum et al.47 draws our attention to the fact that gymnasts with wrist pain consistently present positive UV. In contrast, other authors state that there is a higher tendency to find wrist pain in gymnasts with negative UV,4 and 12 while others do not even consider Unoprostone UV to be a determinant factor PLX3397 in vitro in pain onset.18 Contrary to the data gathered by DiFiori et al.12 we did not find significant differences in the UV negative values between gymnasts with and without wrist pain, independently of gymnasts’ hand dominance. These contradictory results may be attributed either to intrinsic such as

different UV values in the same category, radio and ulna areas, articular surfaces, maturational status, ligament laxity, strength, height, weight, previous injuries, cysts presence, extrinsic factors such as training methodology, intensity, volume and duration of training, equipment and apparatus used. UV may not be per se a determinant factor of wrist pain and/or wrist injuries. Another factor which cannot be excluded is the possible damage to the soft tissues. In fact, wrist pain has long been a problem in terms of diagnosis, partially because of its complex anatomy and the many possible causes of pain in this region. 51 The negative UV has been associated with Kienböck’s disease (avascular necrosis of the lunate),38 and 40 however this theory remains controversial.52 One possible reason to explain the avascular necrosis of the lunate in negative UV wrists may be that during its movements the loads are distributed in the medial part of the distal radius, in the lunate fossa and sigmoid notch.