What is the Difference Between Metacarpal and Metatarsal

The main difference between metacarpal and metatarsal is that metacarpal bones occur in the hand, whereas metatarsal bones in the foot.

Metacarpal and metatarsal bones are two analogous bones that occur between the carpal and tarsal bones and phalanges. 

Key Areas Covered

1. What is Metacarpal
– Definition, Structure, Function
2. What is Metatarsal
– Definition, Structure, Function
3. Similarities Metacarpal and Metatarsal
– Outline of Common Features
4. Difference Between Metacarpal and Metatarsal
– Comparison of Key Differences

Key Terms 

Metacarpal, Metatarsal

What is Metacarpal

Metacarpal bones are long bones that occur in the intermediate part of the hand. They occur between the phalanges and the carpal bones. Significantly, they form a connection to the forearm. Also, they are analogous to the metatarsal bones in the foot. Metacarpus is another name for the metacarpal bones. In addition to that, metacarpal bones are smaller types of long bones consisting of a shaft, distal head, and a wide proximal base. Metacarpal bones articulate with the carpal bones forming carpometacarpal joints. Also, they articulate with phalanges, forming metacarpophalangeal joints. Notably, there are five metacarpal bones named in the radio-ulnar direction.

Figure 1: Metacarpal Bones

Furthermore, the first metacarpal bone articulates with the trapezium. The second metacarpal bone articulates with the trapezium, trapezoid and capitate. Also, the third metacarpal bone articulates with capitate. Further, the fourth metacarpal bone articulates with the hamate. Further, metacarpal bones contain a long shaft. However, the head of the metacarpal bones is rounded and occurs on the distal end. The knuckle is the prominence on the dorsal surface of the hand. Significantly, the function of the metacarpals is to form a longitudinal arch that accommodates the muscles, tendons, and nerves of the palm.

What is Metatarsal

Metatarsal bones are another type of small long bones that occur in the foot. Five metatarsal bones occur between the tarsal and phalanges of the foot. The first metatarsal starts beneath the big toe, and it moves towards the fifth metatarsal bone on the lateral side. Structure-wise, the three distinct parts of the metatarsal bones are the proximal base, the slender shaft in the middle, and the distal head. Also, the proximal base articulates with the tarsal bones, forming tarsometatarsal joints. In addition, the distal head articulates with the proximal phalanges forming metatarsophalangeal joints. Further, metatarsal bones articulate with each other, forming intermetatarsal joints.

Figure 2: Metatarsal Bones

Moreover, metatarsal bones are vital in forming arches of the foot. It is essential for bearing weight, balance, and walking.  

Similarities Between Metacarpal and Metatarsal

• Metacarpal and metatarsal bones are two types of bones that occur in the hand and foot, respectively.
• A group of five bones occurs in these bones.
• They occur between the carpal and tarsal bones and phalanges, respectively.
• They are long bones. 

Difference Between Metacarpal and Metatarsal

Definition

Metacarpal refers to any of several tubular bones between the wrist (carpal) bones and each of the forelimb digits in land vertebrates. In contrast, metatarsal refers to any bone of the foot between the ankle and the toes.

Occurrence

Metacarpal bones occur between the carpals and phalanges in the hand, while metatarsal bones occur between the tarsals and phalanges in the foot.

Structure

Metacarpal bones consist of a shaft, distal head, and a wide proximal base, while metatarsal bones are a group of five long bones located in the metatarsus of the foot.

Joints

Metacarpal bones form two types of joints: carpometacarpal joints and metacarpophalangeal joints, while metatarsal bones form three types of joints: tarsometatarsal joints, metatarsophalangeal joints, and intermetatarsal joints. 

Function

Metacarpal bones form a longitudinal arch that accommodates the palm’s muscles, tendons, and nerves. In contrast, metatarsal bones function in force absorption and support as a rigid lever during gait propulsion. 

Conclusion

In brief, metacarpal and metatarsal bones are long bones in the hand and foot. Metacarpal bones occur between the carpal and phalanges. They consist of a shaft, a distal head, and a wide proximal base. They accommodate muscles, tendons, and nerves of the palm. In comparison, metatarsal bones occur between the tarsal and phalanges. They function in force absorption, support, and as rigid gait propulsion. Therefore, the main difference between metacarpal and metatarsal is their occurrence and function. 

References:

1. Jana Vasković, (2023, April 12). Metacarpal Bones. Kenhub. 
2. O’Leary, C. (2023, April 4). Metatarsal Bones. Kenhub. 

Image Courtesy:

1. “Metacarpal bones (left hand) 01 palmar view with label” By DBCLS – Own work (CC-BY SA 2.1 jp) via Commons Wikimedia
2. “Metatarsal bones01 – superior view” By DBCLS – Own Work (CC-BY SA 2.1 jp) via Commons Wikimedia