Glasoe Ward Mylo, Allen Mary K, Kepros Ted, Stonewall Laurie, Ludewig Paula M
J Orthop Sports Phys Ther. 2002 Nov;32(11):560-5; discussion 565-7. doi: 10.2519/jospt.2002.32.11.560.
Retrospective case-control study.
To examine the amount of dorsal first ray mobility in subjects having a history of stress fracture of the second or third metatarsal as compared to control subjects, and to test the influence of navicular drop, length of the first ray, and generalized joint laxity on the measure of dorsal mobility.
[corrected] Instability of the first ray may cause the lesser metatarsals to carry greater weight and contribute to the incidence of metatarsal stress fracture. Stability of the first ray is believed to be compromised when subtalar joint pronation continues into late stance, the first metatarsal is short, or an individual has generalized joint laxity. To date, no research has assessed the relationship of these etiological factors to the measure of first ray mobility.
Fifteen women athletes having a history of a second or third metatarsal stress fracture were matched by age, body mass, and sport activity to women athletes without fracture. Dorsal first ray mobility was quantified by a device using a standard load of 55 N. Change in vertical height of the navicular during stance was the measure of foot pronation. Relative length of the first ray navicular segment compared to the length of the second ray navicular segment was measured by caliper. Generalized joint laxity was evaluated using the Beighton 9-point scale. Within-day repeated measures assessed reliability. Differences between groups were determined by independent t test. Multiple polynomial regression analysis assessed the relationship between dorsal mobility and navicular drop, length of the first ray, and joint laxity.
Interrater reliability coefficients ranged from 0.36 for metatarsal length to 0.71 for navicular drop. The intrarater reliability coefficient for dorsal first ray mobility was 0.93. Dorsal first ray mobility was not significantly different between the 2 groups. With regression analysis, the Beighton score was the only variable retained as a significant predictor of dorsal mobility (R2 = 0.24).
Results do not support the theory that describes the unstable first ray as a common cause of metatarsal stress fracture. In addition, this investigation found generalized joint laxity to be a significant predictor of dorsal first ray mobility.
回顾性病例对照研究。
比较有第二或第三跖骨应力性骨折病史的受试者与对照受试者的第一跖骨背侧活动度，并测试舟骨下降、第一跖骨长度和全身关节松弛度对背侧活动度测量的影响。
第一跖骨不稳定可能导致较小的跖骨承受更大的重量，并导致跖骨应力性骨折的发生。当距下关节内旋持续到站立后期、第一跖骨较短或个体有全身关节松弛时，第一跖骨的稳定性被认为会受到损害。迄今为止，尚无研究评估这些病因因素与第一跖骨活动度测量之间的关系。
15名有第二或第三跖骨应力性骨折病史的女运动员与无骨折的女运动员按年龄、体重和体育活动进行匹配。使用标准负荷为55N的装置对第一跖骨背侧活动度进行量化。站立时舟骨垂直高度的变化是足部内旋的测量指标。用卡尺测量第一跖骨舟骨段与第二跖骨舟骨段长度的相对长度。使用Beighton 9分法评估全身关节松弛度。日内重复测量评估可靠性。组间差异通过独立t检验确定。多元多项式回归分析评估背侧活动度与舟骨下降、第一跖骨长度和关节松弛度之间的关系。
评分者间可靠性系数范围从跖骨长度的0.36到舟骨下降的0.71。第一跖骨背侧活动度的评分者内可靠性系数为0.93。两组之间的第一跖骨背侧活动度无显著差异。通过回归分析，Beighton评分是唯一保留为背侧活动度显著预测因子的变量（R2 = 0.24）。
结果不支持将不稳定的第一跖骨描述为跖骨应力性骨折常见原因的理论。此外，本研究发现全身关节松弛度是第一跖骨背侧活动度的显著预测因子。
