WristandHand
6
Plate448
LumbricalMusclesandBursae,Spaces,andSheaths:Schema
Thenar space
Midpalmar space
(Synovial) tendon
sheaths of fingers
Usual arrangement
Intermediate bursa
(communication
between common
flexor sheath [ulnar
bursa] and tendinous
sheath of flexor pollicis
longus [radial bursa])
Flexor digitorum
profundus tendons
1st and 2nd lumbrical muscles
(unipennate)
Distal lumbrical tendons
insert into extensor
expansion system
Common variation
3rd and 4th lumbrical muscles (bipennate)
Proximal lumbrical tendons arise from
flexor digitorum profundus tendons
Flexor digitorum
superficialis tendons (
cut
)
Lumbrical muscles: schema
Palmar ligaments (volar plates)
A2
C2
A3
C3
A4
C4
A5
Tendinous sheath of flexor
pollicis longus (radial bursa)
Common flexor sheath
(ulnar bursa)
Lumbrical muscles
(in fascial sheaths)
(Synovial) tendon sheath
Tendons of
flexor digitorum
superficialis
and profundus
muscles
Note: Flexor digitorum superficialis and
profundus tendons encased in synovial
sheaths are bound to phalanges by fibrous
digital sheaths made up of alternating
strong anular (A) and weaker cruciform (C)
parts (pulleys).
Camper chiasm
A1
C1
See±also±
Plate 445
±
