IJCRR

IJCRR - 9(7), April, 2017

Pages: 19-22

Date of Publication: 11-Apr-2017

A Comparative Study of Carrying Angle with Respect to Sex and Dominant Arm in Eastern Population of Nepal

Author: Rakesh Kumar Adhikari, Subodh Kumar Yadav, Abhishek Karn

Category: Healthcare

Abstract:Objective: To find the gender and dominant handedness difference in the carrying angle of adolescent males and females of eastern population of Nepal.
Methods: The carrying angle was measured by a goniometer in 100 healthy subjects without any anomaly, pathology or asymmetry in shoulder, elbow or wrist (50 males and 50 females) by extending, supinating and fixing each forearm and placing the fixed arm of the goniometer on the central longitudinal axis of the upper arm and the adjustable arm of the goniometer on the central longitudinal axis of the lower arm. The means were evaluated using the Student t-test where p < 0.05 was considered to be statistically significant.
Results: The mean carrying angle of males on the dominant upper limb was 11.72\?1.37 and the non-dominant upper limb was 10.02\?1.5 and the mean carrying angle of females on the dominant upper limb was 13.7\?2.09 and the non-dominant upper limb was 11.74\?2.03. The carrying angle was significant greater in females (p < 0.00001) and in the dominant arm in both sexes (p < 0.00001).
Conclusions: Our observation of carrying angle can be used to assess traumatic elbow injuries and as an adjunct to identification of skeletal remains in forensic practice in this population.

Keywords: Carrying angle, Gender, Dominant arm, Adolescents

Full Text:

Introduction

The arm and the forearm are not aligned in humans, which is most obvious when the elbow is straight and the forearm fully supinated. An acute angle at the elbow medially made by the long axis of the humerus and the long axis of the ulna in the anatomic position is recognized as the carrying angle.¹ A little degree of cubitus valgus is fashioned by the axis of a radially swerved forearm and the axis of the humerus which assists the arms whilst walking to move to and fro without thumping the hips.² The normal carrying angle in males is 5°-10° and slightly greater in females being 10°-15°. 3 If this angle is > 15°, it is called cubitus valgus whearas if it is < 5° it is called cubitus varus.³ The angulation is as a consequence of the configuration of the articulating surfaces of the humeral condyles that articulate with the radius and ulna. This angulation vanishes when the forearm is pronated and the elbow is in full extension and when the supinated forearm is flexed alongside the humerus in full elbow flexion.⁴

The angle differs noticeably between individuals and it is greater in females as compared to males and greater in adults as compared to children. Females have narrower shoulders and wider hips than males which may be a suitable cause for having a more acute carrying angle and is therefore deemed as one of the secondary sexual characters.^5-9

Nevertheless, there is a wide overlap in this angle between males and females, and a gender difference has not been steadily scrutinized in scientific studies.^{2, 10} Therefore, this present study was carried out to estimate the gender dominant handedness difference in the carrying angle of pubescent males and females of eastern population of Nepal. Furthermore, our study might be helpful in monitoring of traumatic elbow injuries which frequently necessitate appraisal of the carrying angle. Additionally, the forensic experts may employ our study to determine the gender of an individual of this area from skeletal remains.

Materials and Methods:

A total of 200 elbows of 100 healthy young males and females belonging to the age group of 16 to 24 years with normal bony configuration in equal sex ratio were examined at the Department of Human Anatomy of Nobel Medical College Teaching Hospital, which is situated in eastern Nepal. Individuals with shoulder, elbow or wrist pathologies, asymmetry, congenital malformations, history of elbow surgery, and fracture of limbs were excluded from the study. They were placed in anatomical position and the bony landmarks (olecranon process of the ulna, head of the radius, medial and lateral epicondyles of humerus and head of ulna) were acknowledged by means of palpation. Then the carrying angle was measured by a goniometer by extending, supinating and fixing each forearm. The fixed arm of the goniometer was placed on the central longitudinal axis of the upper arm and the adjustable arm of the goniometer was placed on the central longitudinal axis of the lower arm.¹¹

Figure 1

The angle thus measured was noted by two observers to evade interobserver disparity. The carrying angle of dominant and non-dominant hands was recorded separately.

Statistical Method:

The obtained data were statistically analyzed using the SPSS® for Windows, Version 17.0.  Continuous variables means were evaluated using the Student t-test where p < 0.05 was considered to be significant.

Results

 The mean carrying angle of males on the dominant upper limb was 11.72±1.37 and the non-dominant upper limb was 10.02±1.5 and the mean carrying angle of females on the dominant upper limb was 13.7±2.09 and the non-dominant upper limb was 11.74±2.03.

In this study we observed that there was a significant difference (p< .00001) between the carrying angles of dominant and non-dominant hands in the same gender as well as in the carrying angles of dominant hands in between males and females as shown in the tables below.

Table 1

Table 2

Table 3

Figure 2

Discussion

In this present study, the mean carrying angle of males on the dominant upper limb was 11.72±1.37 and the mean carrying angle of females on the dominant upper limb was 13.7±2.09. The mean carrying angle of dominant hand in females was more compared to that of males which was found to be statistically significant. The first researcher to carry out a study on variation of carrying angle in between males and females was Potter H.P who observed the carrying angle to be greater in females as compared to males.⁵ Except few researchers who found no significant difference between the carrying angles of males and females ^10-14 most of the study shows that the carrying angle of females was greater than males ^{2, 5- 9, 16-24} also observed by our study which shows that the carrying angle of dominant hand of females and males differ statistically.

We also observed that the mean carrying angle of the dominant hand was more as compared to the non-dominant hand in either sexes (males:11.72±1.32 vs 10.02±1.50; females: 13.7±2.09 vs 11.74±2.03) and this too was statistically significant finding also observed in other studies.^21,22,24  This significant difference between the carrying angles of the dominant and non-dominant sides may imply more laxity of the ligament at the medial elbow or bony remodeling to adapt more stress in the dominant hand.

However, we did not analyze the influence of variables like height, age and race of the individual, length of the arm, length of the forearm, and width of the hip to the carrying angle.

Conclusion

Our subjects were adolescents and the carrying angle was significantly more in females as compare to males which may be due to laxity of articular ligaments and a wider pelvis, the outcome of which is a greater tangential divergence of the forearm on the arm. The carrying angle of dominant arm was observed to be greater than the non-dominant arm in both males and females which was statistically significant. This may be because of bony remodeling to adapt more and repeated stress in the dominant arm due to its more frequent use as compared to the non-dominant arm.

Our observed values will be important in the management of traumatic elbow injuries and in the diagnosis of diseases of the lateral and medial epicondyles which frequently necessitate appraisal of the carrying angle. Our finding can also be used as an indicator of gender in this population and thus an adjuvant forensic parameter to aid in identification of human remains which is an important part of medicolegal practice.

Acknowledgement

Authors acknowledge the immense help received from the scholars whose articles are cited and included in references of this manuscript. The authors are also grateful to authors / editors / publishers of all those articles, journals and books from where the literature for this article has been reviewed and discussed.

Ethical Clearance

Ethical clearance was obtained from the Institutional Review Committee of Nobel Medical College and Teaching Hospital, Biratnagar-5, Morang.

Source of Funding

None declared.

Conflict of interest

None declared.

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