Front Matter

354 Canine Sports Medicine and Rehabilitation

This chapter offers an overview of some of the
common pelvic limb conditions seen clinically;
the first section discusses pelvic limb soft tis­
sue injuries. A keen diagnostician will palpate
all structures carefully to identify changes or
discomfort in soft tissues that may have yet to
be published as a specific condition. Applying
knowledge of pertinent anatomy with function,
physical examination findings, and appropriate
diagnostic tools will provide an accurate and
specific diagnosis, and proposal of treatment
options.

Iliopsoas strain

Anatomy

The iliopsoas muscle represents the fusion of the
psoas major and iliacus muscles (Figure 14.1).
The psoas major muscle arises from the trans­
verse processes of the lumbar vertebrae of the
ventral lower spinal column at L2 and L3 and
the bodies of L4 to L7. The iliacus muscle
arises from the ventral surface of the ilium.
The two muscles combine and have a common
insertion on the lesser trochanter of the femur.
The action of this muscle is hip flexion with
external femoral rotation, and lumber flexion
(Evans, 1993).

Pathophysiology

Iliopsoas muscle strains are believed to occur

during eccentric contraction, when the muscle is

contracting while lengthening (Breur & Blevins,

1997; Nielsen & Pluhar, 2005). The weakest area

is the muscle–tendon junction, and strains most

often occur at or near this junction. However,

midbody and proximal psoas major injury may

be noted as well. Iliopsoas strain may be a

primary injury or secondary to an underlying

orthopedic or neurological condition. Primary

strains can occur as acute stretch‐induced

injuries or from chronic repetitive use. In per­

formance dogs, there may be a long‐standing

cycle of microtearing, particularly if the strain is

ongoing due to poor fitness, repetitive training,

improper warm‐ups, and/or fatigue compensa­

tion. Slipping into sudden abduction, jumping

out of a vehicle or from give‐way footing, and

roughhousing with other dogs may be precipi­

tating events in any type of dog.

Pes anserinus injury

Anatomy

The pes anserinus (Latin for “goose foot”) is the

conjoined tendon group of the sartorius, gracilis,

semimembranosus, and semitendinosus mus­

cles on the medial aspect of the proximal tibia.

This web‐like structure is unique in that the four

muscles are innervated by three different nerves

(femoral, obturator, and tibial, respectively). The

four muscle groups also have very different

functions (Evans, 1993). The cranial sartorius is a

long muscle that spans from the ilium to the

patella and cranial medial aspect of the tibia.

Biomechanically, the sartorius primarily flexes

the hip and the stifle, but the cranial belly also

serves to extend the stifle. The gracilis is the only

adductor to cross the stifle. The semimembrano­

sus and semitendinosus extend the hip and tar­

sus and flex or extend the stifle (Evans, 1993).

Pathophysiology

Injury to this tendon group can cause lameness

and pain on palpation of the proximal medial

aspect of the stifle. Pain in this region may lead

Psoas minor

Psoas major

Iliacus

Figure 14.1 Iliopsoas muscle anatomy. The iliopsoas
muscle represents the fusion of the psoas major and
iliacus muscles. Source: Illustration by Dr. Faith Lotsikas.