Human Bursæ Enumerated.
The following is a list of bursæ in man of which some are normal or always present, and others which are both occasional in their appearance and often imperfectly developed.
Front of Neck.
(A)
One in front of the pomum adami.
(B)
One in the thyro-hyoid space extending to the under surface of the hyoid bone.
(C)
One beneath the stemo-hyoid muscle.
(D)
One above the hyoid bone.
Pharynx. A small central pit constituting a single bursa the bursa pharyngea.
Behind the angle of the lower jaw. One.
On the symphysis of the chin. One.
On the Acromion process. One.
Beneath the deltoid and the acromion process, one large bursa often opening into the shoulder-joint.
Elbow.
(A)
One over the olecranon.
(B)
One occasionally over the inner epicondyle.
(C)
One over the internal condyle of the humerus.
(D)
One over the external condyle of the humerus.
(E)
Small one between the biceps tendon and the head of the radius.
(F)
Often a second bursa which separates the tendon from the oblique ligament crossing it.
Wrist.
(A)
One over the styloid process of the radius.
(B)
One over the styloid process of the ulna.
Hand.
(A)
One over each of the metacarpo-phalangeal joints.
(B)
One over each of the phalangeal joints.
Region of hip.
(A)
One over the anterior superior spine of the ilium.
(B)
Large one between the great trochanter and the gluteus maximus muscle.
(C)
One between the gluteus medius and the bone.
(D)
One between the gluteus minimus and the bone.
(E)
One between the psoas and iliacus muscles often opening into the hip-joint.
Thigh.
(A)
One over external condyle of the femur.
(B)
One over internal condyle of the femur.
Knee-joint. The prepatellar bursæ.
(A)
Between the skin and superficial fascia at the lower edge of the patella there is often a small subcutaneous bursa.
(B)
Beneath the superficial fascia over the fascia lata there is always a large interfascial bursa, intersected by smooth fibrous bands extending downwards over the upper part of the patellar ligament.
(C)
One still deeper between the deep fascia and front of the bone there is a layer of lax connective tissue.
(D)
Sometimes a third or deep subfascial bursa.
“These bursæ over the knee-joint appear in fœtal life and vary in size in persons of different occupations, being often large in housemaids and carpet-nailers, and often communicating with each other.”[68]
(E)
Occasionally the upper part of the synovial pouch of the knee-joint is shut off from the general cavity and forms a separate bursa beneath the extensor muscles. It always communicates with the knee-joint though originating independently.
In the Ham.
| (A) | Large bursa between the inner condyle of the femur andthe gastrocnemius muscle, often opening into the joint. | ||
| (B) | A smaller one on the outer side. | ||
| (C) | One between the biceps tendon and the external lateral ligament. | ||
| (D) | One between the semimembranosus |  | and the bone. |
| (E) | One between the popliteus | ||
| (F) | One between the sartorius | ||
| (G) | One between the gracilis | ||
| (H) | One between the semitendinosus | ||
Tibia.
(A)
One over the tuberosity.
Ankle.
(A)
Over both malleoli.
(B)
Between the tendo achillis and the os calcis.
Foot.
(A)
Over plantar surface of the great toe.
(B)
Over plantar surface of the little toe.
(C)
Over the dorsal surfaces of all the phalangeal joints of the toes.
(D)
Over the dorsal surface of metatarso-phalangeal joint of the great toe.
(E)
Over the plantar surfaces of the metatarso-phalangeal joints of all the toes.
I calculate that there are at least fifty-two separate bursæ (about one hundred on the two sides of the body) in the normal or fully developed state, though of these many will be found either absent or with very little of the full structure of a bursa. One small but significant point may be referred to here. We are all familiar with the prominence of the knuckles of the hand and the very efficient bursæ which cover them, but most persons do not recognise that the foot has no such knuckles (or prominent metatarso-phalangeal joints) and no bursæ over these joints, except that of the great toe which happens to be very much more exposed to friction and has a much greater range of action than the other four metatarso-phalangeal joints. This might be called by some persons a beautiful bit of adaptation for locomotion and by others an equally admirable bit of adaptation produced by locomotion.