The document describes the anatomy and characteristics of the phalanges in the hand. There are 14 phalanges total in each hand. The proximal phalanges are the largest and articulate with the metacarpals at the metacarpophalangeal joints. The middle phalanges are present in each finger except the thumb. The distal phalanges are the shortest and attach to the pulps of the digits. Together the phalanges provide flexion, extension, adduction and abduction of the fingers at the interphalangeal joints. They are stabilized by various ligaments and muscles that insert onto the phalanges.

1. PHALANGES
Upper limb

2. Characteristics
 Long Bone
 Phalanges have:
 Base
 Shaft
 Head
 14 Phalanges in each hand.
 Except thumb all 4 digits have Proximal, Middle, Distal
Phalanx.
 Connected by Interphalangeal Joint.
 Vascularized by :
 Palmar Digital Arteries.

3. PROXIMAL PHALANX
 Total 5, 1 in each Digits.
 Largest Phalanges, except for thumb which is
shortest & stout.
 Base:
Concave, oval shaped Articular Facet.
Articulate with Metacarpal Head to form MCP
Joint.
Contains non-Articular Tubercle for attachment of
Various Soft Tissue.

4. BODY/ SHAFT
 Tapers Distally
 Has 2 surfaces :
 Dorsal Surface
 Palmar Surface
 Dorsal Surface:
 Round & Smooth.
 Convex in Transverse Plane.
 Palmar Surface:
 Flat & Rough especially on the sides where Flexor
Fibrous Sheath of digits attach.
 Flat in Transverse Plane.
 Concave in Sagittal Plane.

5. HEAD
 Expanded & Round distal part.
 Pully shaped articular Surfaces with base of
Middle Phalanx to Form the Proximal
Interphalangeal PIP Joint.
 Smooth groove on palmar side.
 Groove represent the attachment point of
Collateral Interphalangeal Ligament of Hand.

6. CHARACTERISTICS
• Various Ligament attach to Proximal Phalanges
• Digital Fascial Complex which attaches the
surrounding Subcutaneous & Neurovascular to
Bony Phalanges.
• Collateral & Palmar Metacarpophalangeal
Ligament attach to the head supporting PIP
Joint.
• Proximal Phalanges covered by the Extensor
Expansion of Hand.
• Function: Flexion, Extension, Adduction &
Abduction.

7. INSERTION
 Posterior Forearm Muscle:
Extensor Digitorum
Extensor Pollicis Brevis
Extensor Digiti Minimi
Extensor Indicis
 Metacarpal Muscle:
Lumbricals
Palmar Interossei
Dorsal Interossei
 Thenar Muscle:
Flexor Pollicis Brevis
Adductor Pollicis
 Hypothenar Muscle:
Abductor Digiti Minimi
Flexor Digiti Minimi

9. MIDDLE PHALANGES
 Middle Phalanges present in each Finger except Thumb.
 Consist of :
 Base
 Body
 Head
 Base of each Middle Phalanx have 2 concave shaped articular facet.
 Head of Middle Phalanx have Pully-like Shape.
 Articulate with base of Distal Phalanges to form Distal Interphalangeal Joint
(DIP Joint).
 Middle Phalanges are reinforced by Collateral Interphalangeal Ligaments &
Extensor Expansion of Hand.

10.  Collateral Interphalangeal Ligament attach Base
& Head of middle Phalanges to reinforce the PIP
& DIP Joints
 Function:
Flexion (at PIP Joint)
Extension (at PIP Joint)
 Insertion:
Flexor Digitorum Superficialis Muscle attach to
side of Middle Phalanges, Flexing them at PIP
Joints

11. DISTAL PHALANGES
 5 Distal Phalanges
 Shorter & Slightly Thicker
 Have:
 Base
 Body
 Head
 Base:
 Have Double Articular Facet, which articulate Middle
Phalanx.
 Have Smooth, round Dorsal Surface
 Palmar Surface is wrinkled and Irregular.

12.  Head:
 Non-Articular
 Irregular, Curved Shaped Distal Tuberosity.
 Serve as anchor point for Pulps of Digits
 Distal Phalanges are stabilized by :
 Distal Fascial Complex
 Collateral Ligament
 Extensor Expansion
 Collateral Ligament Attach to Base of Distal
Phalanges to Reinforce DIP Joint
 Distal Phalanges Function :
 Flexion (at DIP Joints)
 Extension (at DIP Joints)
 Insertion: 2 Forearm Extensor & 1 Flexor Muscle
 Flexor Digitorum Profundus
 Flexor Pollicis Longus
 Extensor Pollicis Longus