Learn about the anatomical structure and features of the hand, wrist and foot.
Structure of the Hand and Wrist
Each hand has five fingers. The outermost is the thumb, and the other four are the fingers in the narrow sense. The wrist contains joints formed by the radiocarpal joint, the radius, the ulna, the finger bones (phalanges) and the metacarpal bones.
- The fingers are the thumb, index finger, middle finger, ring finger and little finger.
- In the wrist joint, ligaments stabilize the many bones, while muscles and tendons support movement.
- The median and ulnar nerves and the radial and ulnar arteries run through the wrist.
Anatomical Form and Features of the Hand
Each finger except the thumb consists of one metacarpal bone and three phalanges.
- The metacarpophalangeal joints lie between the metacarpal bones and the phalanges.
- Horizontal skin creases are found over the joints between the finger segments.
- Each finger has flexor and extensor tendons, with nerves and blood vessels running along both sides.
- Many muscles that move the fingers and wrist are located in the wrist.
- Ligaments between the many bones of the wrist joint provide stability.
- The hand grasps objects and provides the sense of touch.
- It is capable of finer movements than any other part of the body.
- Tendons and ligaments of the wrist joint control bending and straightening of the wrist.
The foot supports the body. Its main roles are to support the body when standing or walking and to absorb the impact of movement. The foot has four arches: the medial longitudinal arch, the lateral longitudinal arch, the forefoot transverse arch and the midfoot transverse arch. These arches absorb shock when you stand, walk or run. Without them, the foot's ability to recover its shape would drop sharply, and it could not absorb shock during movement.
Structure of the Foot
Each foot consists of 26 bones and is divided into three parts: the hindfoot, the midfoot and the forefoot. It also includes joints, muscles and tendons.
- The heel bone is the largest bone of the foot and is the first to bear body weight when walking.
- The big toe has two bones, and each of the other toes has three.
- The big toe is the largest because it bears and supports the most force when moving and standing.
- The foot has 19 muscles and tendons, 18 of which are on the sole.
- 107 ligaments help the foot withstand tension and twisting.
- Sole (plantar side): the part that touches the floor or ground
- Top of the foot (dorsal side): the upper side, opposite the sole
- Heel: the part of the sole below the calcaneus (heel bone)
- Bones: 7 tarsal bones, 5 metatarsal bones and 14 phalanges
