What is the Difference Between Male and Female Clavicle

The main difference between male and female clavicle (or the collarbone) is that the male clavicle is longer, thicker, more curved, and less smooth. But, the female clavicle is shorter, thinner, less curved, and smoother. Furthermore, the mid-shaft circumference value is higher in the male clavicle. But, the mid-shaft circumference value is lower in the female clavicle. Moreover, the acromial end of the male clavicle is on a level with or slightly higher than the sternal end when the arm is pendant. In contrast, the acromial end of the female clavicle is lower than the sternal end.  

In brief, the male and female clavicle are two types of long bones, which are horizontally located in the human body. Generally, they serve as one of the main factors of sex determination; especially, in cases where skeletal remains are available for forensic identification. 

Key Areas Covered 

1. What is Clavicle
     – Definition, Anatomy, Function
2. What is Male Clavicle
     – Anatomical Significance
3. What is Female Clavicle
     – Anatomical Significance
4. What are the Similarities Between Male and Female Clavicle
     – Outline of Common Features
5. What is the Difference Between Male and Female Clavicle
     – Comparison of Key Differences

Key Terms 

Acromial end, Clavicle, Collarbone, Female Clavicle, Male Clavicle, Sex Determination, Shaft, Sternal End

What is Clavicle 

The clavicle or the collarbone is the only horizontally-occurring long bone of the human body. They occur as a part of the anterior human thoracic skeleton and show a higher degree of variability in size and shape in different racial groups, as well as in the two genders.

Figure 1: Clavicle Anatomy

Anatomy 

Looking at its anatomy, the clavicle has a double-curved, S-shaped outline. Also, the three regions of a clavicle bone are the sternal end, acromial end, and the shaft.  

Sternal End  

Moreover, the sternal (medial) end is quadrangular, and it articulates with the clavicular notch of the manubrium of the sternum, and thus, forming the sternoclavicular joint. Also, the extension of the articular surface of the medial end attaches to the first costal cartilage.   

Acromial End  

But, the acromial (lateral) end is flat, and it contains facets for the articulation with the shoulder, and thus, forming the acromioclavicular joint. Further, its anterior is concave forward, while the posterior border is convex backward.   

Shaft  

Typically, two-thirds of the shaft is medial while the remaining one-third is lateral. Here, the medial shaft is thicker while the lateral shaft is thinner.  

Further, there are two clavicles, which occur on each side of the body. They are known as the right and the left clavicle according to the corresponding side of the body. Besides, all clavicles are bilaterally asymmetric; left clavicles being significantly longer in length, lighter in weight, smooth in texture and less curved than the right side bones.  

Function  

Each clavicle occurs just above the first rib. Functionally, both clavicles take part in the formation of the shoulder girdle or the pectoral girdle along with the two scapulae in humans. Here, each clavicle medially articulates with the sternum and laterally with the acromion of the scapula. Further, the shoulder girdle allows the attachment of each arm to the skeleton. Moreover, each clavicle provides rigid support to the upper limb together with the scapula. Thus, this provides the upper limb with a maximum range of movement while keeping it away from the thorax. In addition to these, the clavicles permit the free movement of the scapula through the thoracic wall. 

Figure 2: Pectoral Girdle

On top of the functions above, both clavicles provide sites for the attachment of muscles. Here, the lateral one-third attaches to the trapezius muscle in its posterior surface and deltoid muscle in its anterior surface. Meanwhile, the medial two-thirds attaches to the sternocleidomastoid muscle in the superior surface, pectoralis major muscle in the anterior surface, and subclavian muscle in the inferior surface – subclavian groove.

Importantly, the clavicle is the most commonly fractured bone in the body. Typically, it can be fractured either by a direct hit or due to impacts to the shoulder from a force of falling on outstretched arms.   

What is the Male Clavicle 

The male clavicle is the type of clavicle in males, and it is longer and thicker, comparatively. Generally, the main significant features of the male clavicle are its higher mid clavicular circumference (34.87 mm), linear length (141.30 mm), posterior curved length (151.65 mm), and medial 2/3 and lateral 1/3 junction circumference (40.50 mm). Also, the male clavicle has a large subclavian groove and nutrient foremen. Notably, according to the occupation-dependent osteological variations, thicker and more-curved clavicles occur in manual workers. 

What is Female Clavicle 

In contrast to male clavicle, the female clavicle is shorter and thinner. Therefore, it has lesser values in midclavicular circumference (28.67 mm), linear length (125.71 mm), posterior curved length (134.36 mm), and medial 2/3 and lateral 1/3 junction circumference (34.93 mm). Also, female clavicles are smoother and less-curved. 

Similarities Between Male and Female Clavicle  

• Male and female clavicle are two types of long bones, which occur horizontally in the body as a part of the appendicular skeleton.  
• They consist of two ends; the acromial (lateral) and the sternal (medial) ends and a shaft.  
• Also, the shaft is curved with a  forward convexity in its medial two-third and a forward concavity in its lateral one third.    
• They are one of the bones used for sex determination especially in cases where only skeletal remains are available for forensic identification.    
• Both metric (physical dimensions) and non-metric (characteristic appearance) features of the clavicle can have a decisive role in forensic identifications.  
• The clavicle measurements or metric features include the weight (W), linear length (L), anterior curved length (ACL), posterior curved length (PCL), mid-clavicular circumference (MC), medial 2/3rd and lateral 1/3rd junction circumference (JC), and mid-clavicular anteroposterior diameter  (APD).  
• Non-metric features include the subclavian groove, nutrient foramen and ‘type’ of the clavicle, etc. 

Difference Between Male and Female Clavicle 

Definition 

Male clavicle refers to the clavicle that occurs in males and comparatively, is longer, thicker, and more curved than female clavicle.  The female clavicle refers to the clavicle that occurs in females, and comparatively, it is shorter, thinner, and less curved. 

Metric Features 

The metric features of the male clavicle include: the weight is 16.57 g, the linear length is 141.30 mm, the anterior curved length is 137.15 mm, the posterior curved length is 151.65 mm, mid-clavicular circumference is 34.87 mm, medial 2/3rd and lateral 1/3rd junction circumference 40.50 mm, and mid-clavicular anteroposterior diameter is 11.71 mm. Meanwhile, the metric features of the female clavicle include: the weight is 10.78 g, linear length is 125.71 mm, anterior curved length is 122.27 mm, posterior curved length is 134.36 mm, mid-clavicular circumference is 28.67 mm, medial 2/3rd and lateral 1/3rd junction circumference 34.93 mm, and mid-clavicular anteroposterior diameter is 9.67 mm. 

Relative Positions of the Acromial and Sternal Ends 

The acromial end of the male clavicle is on a level with or slightly higher than the sternal end when the arm is pendant. But, the acromial end of the female clavicle is lower than the sternal end.  

subclavian Groove 

The male clavicle has a large subclavian groove, while the female clavicle has a small subclavian groove.  

Nutrient Foramen 

The nutrient foramen of the male clavicle may be larger, while the nutrient foramen of the female clavicle may be smaller. 

The ‘Type’ of Clavicle 

The male clavicle is long and robust, while the female clavicle is short and smooth. 

Conclusion 

In brief, the male clavicle is the type of clavicle that occurs in males. Comparatively, it is longer and thicker. Therefore, it has a higher linear length, mid clavicle circumference, and medial 2/3 and lateral 1/3 junction circumference. In addition to these, it has a higher posterior curved length. Meanwhile, the female clavicle is the type of clavicle that occurs in females. However, it is shorter and thinner. On that account, its linear length, mid clavicle circumference, and medial 2/3 and lateral 1/3 junction circumference are comparatively smaller similarly as the posterior curved length. Therefore, the main difference between male and female clavicle is their anatomical features, such as size and shape. 

References:

1. Sehrawat, Jagmahender Singh, and R.k. Pathak. “Variability in Anatomical Features of Human Clavicle: Its Forensic Anthropological and Clinical Significance.” Translational Research in Anatomy, vol. 3-4, 2016, pp. 5–14., doi:10.1016/j.tria.2016.08.001.
2. Doshi, M. A., and Bhaskar B. Reddy. “Determination of Sex of Adult Human Clavicle by Discriminant Function Analysis in Marathwada Region of Maharashtra.” International Journal of Research in Medical Sciences, vol. 5, no. 9, 2017, p. 3859., doi:10.18203/2320-6012.ijrms20173701.

Image Courtesy:

1. “Clavicle 4” By Anatomist90 – Own work (CC BY-SA 3.0) via Commons Wikimedia   
2. “802 Pectoral Girdle” By OpenStax College – Anatomy & Physiology, Connexions Web site. (CC BY 3.0) via Commons Wikimedia