Al-Qattan Noha M, Al-Kharashi Sara K, Al-Hindi Ghada K, Dammas Nada M, Kattan Abdullah E, Al-Qattan Mohammad M
Department of Surgery, King Saud University, Riyadh, Saudi Arabia.
Division of Plastic Surgery, King Saud University, Riyadh, Saudi Arabia.
Plast Reconstr Surg Glob Open. 2019 May 16;7(5):e2144. doi: 10.1097/GOX.0000000000002144. eCollection 2019 May.
The second-to-fourth digit ratio is measured by dividing the length of the index finger by the length of the ring finger. A ratio <1 means that the ring finger is longer; this is known as the male pattern or "A" pattern. A ratio >1 means that the index finger is longer; this is known as the female pattern or "C" pattern. When both fingers are equal in length (ratio = 1), the pattern is labeled as "B" pattern; this may be seen in both sexes. None of the previously reported studies on this topic were reported in the plastic or hand surgery literature. Our aim is to increase the awareness of plastic and hand surgeons to these types of hand patterns and to correlate such patterns to sex, body mass index (BMI), and physical activity in a group of healthy medical students and interns.
We conducted a cross-sectional study on 160 healthy medical students/interns. There were 82 females and 78 males between the ages of 20 and 30. A male pattern (pattern A) was defined as pattern A in both hands or pattern A in one hand and pattern B in the other hand. A female pattern (pattern C) was defined as pattern C in both hands or pattern C in one hand and pattern B in the other hand. The correlation between hand pattern and sex, BMI, and physical activity was done using the chi-square test and Fisher's exact test. A value of <0.05 was considered statistically significant.
Five participants (3.1%) had pattern B in both hands. Another 15 participants (9.4%) had a male pattern in one hand and a female pattern in the other hand. Both of these groups were excluded from the statistical analysis. Pattern A was significantly higher in males, and pattern C was significantly higher in females ( < 0.001). BMI and physical activity did not significantly affect the hand pattern in males. However, the correlations between hand pattern and both BMI and physical activity were significant in females ( = 0.005 for BMI) ( = 0.042 for physical activity).
About 12.5% of the study group did not fit into a male or female pattern. In the remaining 87.5% of the participants, sex correlated with hand pattern. BMI and physical activity significantly affected the hand pattern in females. We believe that our study will encourage plastic surgeons to further investigate the correlation of different hands patterns to other variables of interest in plastic surgery such as masculine facial anthropometric values, hypoplastic breasts, gynecomastia, and lipodystrophy.
食指与无名指长度之比通过将食指长度除以无名指长度来测量。该比值<1意味着无名指更长；这被称为男性模式或“A”模式。比值>1意味着食指更长；这被称为女性模式或“C”模式。当两指长度相等（比值 = 1）时，该模式被标记为“B”模式；男女均可出现这种情况。此前关于该主题的研究均未在整形或手外科文献中报道。我们的目的是提高整形和手外科医生对这类手部模式的认识，并将这些模式与一组健康医学生和实习生的性别、体重指数（BMI）及身体活动情况相关联。
我们对160名健康医学生/实习生进行了一项横断面研究。其中有82名女性和78名男性，年龄在20至30岁之间。男性模式（模式A）定义为双手均为模式A或一只手为模式A且另一只手为模式B。女性模式（模式C）定义为双手均为模式C或一只手为模式C且另一只手为模式B。使用卡方检验和费舍尔精确检验来分析手部模式与性别、BMI及身体活动之间的相关性。P值<0.05被认为具有统计学意义。
5名参与者（3.1%）双手均为模式B。另有15名参与者（9.4%）一只手为男性模式而另一只手为女性模式。这两组均被排除在统计分析之外。模式A在男性中显著更高，模式C在女性中显著更高（P<0.001）。BMI和身体活动对男性的手部模式没有显著影响。然而，手部模式与BMI及身体活动在女性中均存在显著相关性（BMI的P值 = 0.005）（身体活动的P值 = 0.042）。
研究组中约12.5%的人不符合男性或女性模式。在其余87.5%的参与者中，性别与手部模式相关。BMI和身体活动对女性的手部模式有显著影响。我们认为我们的研究将鼓励整形外科医生进一步研究不同手部模式与整形手术中其他感兴趣变量（如男性化面部人体测量值、乳房发育不全、男性乳房发育症和脂肪营养不良）之间的相关性。
