The purpose of this study was to investigate relationship between the shoulder pain and the flexibility of the shoulder in Japanese elite male water polo players. We also conducted to find the physical characteristics of the range of shoulder rotation. Subjects were Japanese elite male water polo players that was 30 (study 1) and 40 (study 2). We measured and compared shoulder flexibility by finger vertebral distance (FVD). In study 2, a standard universal goniometer was utilized to measure range of shoulder rotation with the arm in 90 degrees of abduction. There is significant correlation range of motion on the dominant shoulder showed significant decrease in internal rotation and increase external rotation. The results indicate that decrease exists in the shoulder flexibility of elite water polo players with pain. Furthermore, our findings suggest that prevention or rehabilitation of painful water polo player’s dominant shoulder is considered to be existing two reasons that are at risk of developing shoulder pain because of the repetitive nature of swimming combined with throwing.

This study was conducted to examine the effects of different types of swimming on vision, including contrast sensitivity, depth perception, static visual acuity, number of eyeblinks, and pain scale. Six college water-polo players swam (A) at a water flow rate of 0 m·sec^-1 with floating, (B) at 0.83±0.04 m·sec^-1 with floating, (C) at 1.09±0.05 m·sec^-1 with floating, (D) at 0.83±0.04 m·sec^-1 doing the front crawl (50%VO₂max), and (E) at 1.09±0.05 m·sec^-1 doing the front crawl (80%VO₂max) for 15 min on a swimmill. To avoid the effect by chlorine, the free radical residual chlorine concentration was fixed at 0 ppm in the swimmill.
We found no significant differences in vision before and after A. On the other hand, contrast sensitivity during the test decreased significantly in C and E (p<0.05) . Depth perception and number of eyeblinks increased significantly in C and E (p<0.05) . Subjects had a high pain scale in C and E (p<0.01) . Thus it seems that water flow may disturb of vision. We conclude that it is impor. tant for swimmers to prevent impairment of vision.

The purpose of this study was to investigate the status of contact lens use in the pool for water polo players. A total of 627 male subjects were studied : junior high school players (n=190), high school players (n=188), college players (n=121) and water polo club players (n=128).Results were summarized as follows : 1) The percentage of players using vision correction devices in daily life was 43.38%, and use of contact lenses during water polo play was 30.14% for all subjects. 2) Junior high school players using contact lenses during water polo play showed a significantly lower rate compared with other players (X²=34.38, p<.01). 3) There were a lot of users of disposable type contact lenses during water polo play. 4) Players using contact lenses during water polo play had significantly higher corneal and conjunctival damage than subjects using vision correction devices in daily life and subjects without vision correction devices (X²=13.64, p<.01).We concluded that it was a problem for junior high school players with low vision acuity during water polo play.

This study examined the effects of the use of contact lenses on static and kinetic visual acuity, ocular pain, and blurred vision during a water polo match. Eleven male water polo players participated in this study, and were assigned to one of two groups: contact lens users (CL, n=5) and non-users (NCL, n=5). Both groups participated in a typical water polo match with four 7-min periods and 2-min resting intervals between the four periods. Static and kinetic visual acuity, subjective ocular pain, and blurred vision were measured before the match (pre-test), during the match (after each of four 7-min periods), and during the recovery phase at 5, 15, and 30 min after the completion of the match.Results showed that kinetic visual acuity was significantly lower for the NCL group than for CL in the 4^th period of the match. In addition, for the NCL group, kinetic visual acuity was significantly lower in the 3^rd and the 4^th periods than at the pre-test time. On the other hand, static visual acuity did not significantly differ between the two groups; but, for NCL, static visual acuity was significantly lower in the 4^th period than at the pre-test time. According to self-evaluation scores, ocular pain significantly increased in NCL compared to CL in the 3^rd and 4^th periods. Ocular pain in NCL was significantly higher between the 2^nd period and recovery phase at 5 min than at the pre-test time. Blurred vision was significantly higher in NCL than CL between the 2^nd period and recovery phase at 5 min. Blurred vision in NCL was significantly higher at the same duration than at the pre-test time.These findings indicate that the use of contact lenses may prevent ocular pain and blurred vision, maintaining both the static and kinetic visual acuity at a normal level during a water polo match. Further, the results of this study suggest that the use of contact lenses is effective for water polo players.