A preparticipation examination for athletes should be performed to prevent severe athletic injury by examining physical characteristics related to various injuries. The general joint laxity test has been included among the check-up items considering as relating factor of joint injury. Authors investigated the relationship between the score of general joint laxity for freshmen examination and the incidence of major joint injury, during the succeeding 5 athletic seasons, in eighty-seven collegiate American football players.
Significant higher scores were observed in athletes affected by shoulder injury, and slightly higher scores in those affected by knee joint injury. But, the scores were similar between athletes with and without elbow or ankle injury.
The degree of laxity was associated with shoulder and knee joint injury in a comparison of incidence of these injuries among tight, medium and lax groups.
Authors concluded that general joint laxity is related to the incidence of shoulder and knee joint injury.

The purpose of this study is to investigate the degenerative change of the cervical spine in American football (AF) players. The subjects were 27 collegiate AF players who had an annual radiological examination of the cervical spine. X-ray films of the lateral view were read by digital scanner and the anterior and posterior height of each spine (C 3-C 6) was measured. The subjects were divided into two groups based on experience of AF in high school (inexperienced and experienced) or the position played (lines and backs) .
Although the anterior height did not change from the first grade to fourth grade, the posterior height of C 4, C 5 and C6 significantly increased (P <0.05) . The experienced group showed a faster increase in the rate of posterior height than the inexperienced group. Also, the backs group showed a faster increase in the rate of posterior height than the lines group. The increased posterior height, which sometimes includes bony spur, results in kyphotic change of cervical alignment and impingement of the cervical nerve root. The faster growth rate in experienced or backs groups suggests that higher mechanical stress to the cervical spine and younger start of AF caused degeneration.