RESUMEN
Although decreased dorsiflexion range of motion (DROM) is linked to ankle inversion sprains and other lower limb injuries, the mechanisms underlying these links are not well understood. The purpose of this study was to examine the relationships between DROM and the ankle dorsiflexion and inversion, and the foot progression angles during a sidestep cutting maneuver. Nineteen healthy subjects participated in this study. The loaded DROM in a flexed- knee position was measured. The foot and ankle motions were assessed during the sidestep cutting maneuver using a 3D motion analysis system. The low DROM group displayed smaller dorsiflexion and inversion angles, and greater external foot rotation, and performed the task using a significantly greater percent of their DROM than the high DROM group during the sidestep cutting maneuver. In addition, the smaller DROM was associated with smaller dorsiflexion angles, greater external foot rotation, and greater maximum dorsiflexion angles as a percentage of DROM during the sidestep cutting maneuver. The decreased DROM may prevent the ankle from becoming stable during the sidestep cutting maneuver, therefore the ankle may be vulnerable position to an inversion sprain. The kinematic patterns displayed by individuals with a decreased DROM may be a compensatory strategy for dorsiflexion deficits, which may be associated with ankle and knee injuries.
RESUMEN
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) .<BR>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.
RESUMEN
Injury of the anterior cruciate ligament (ACL) occurs frequently in female gymnasts and basketball players. However, there is no effective method for preventing ACL injury. Recently, a fatigue phenomenon of the ligament tissue has been considered to be the main causative factor in ACL injury.<BR>The present study was done to investigate the relationship between knee laxity and general joint looseness in 34 female college basketball players at an orthopedic medical check-up.<BR>Knee laxity was evaluated in terms of the anterior displacement (AD) value measured by a KT-2000 knee ligament arthrometer at 20 lb. General joint looseness was evaluated in terms of the general joint laxity (GL) score including six major joints and the spine.<BR>There was a significant correlation between the AD value and GL score, the correlation coefficients being 0.48 (p<0.01) at the right knee and 0.54 (p<0.01) at the left knee.<BR>The ACL of athletes with a higher AD would always be exposed to higher anterior stress than in athletes with a lower AD, thus possibly leading to a fatigue state. Therefore, we consider that athletes with a high AD are at greater risk of ACL injury. Our results suggest that the easy GL test is an effective screening method for differentiating those with a high AD and a greater risk of ACL injury.