Page 85 - Canine Lameness

Table 4.3 Myotatic and flexor reflexes of the thoracic and pelvic limbs.
Spinal cord
Reflex site Reflex name segments Named nerve(s) tested Efferent fibers Normal response
Thoracic limb Flexor C6–T2 Axillary, median, musculocutaneous, Flexor muscles of the shoulder, Shoulder, elbow, and
withdrawal radial, thoracodorsal, suprascapular, and elbow, carpus, and digits carpal flexion
ulnar
Biceps a C6–C8 Musculocutaneous Biceps muscle group Elbow flexion
Triceps a C7–T2 Radial Triceps muscle group Elbow extension
Extensor carpi C7–T2 Radial Extensors of the carpus and digits Carpal extension
radialis a
Pelvic limb Flexor L4–S1 Sciatic and femoral Femoral nerve − rectus femoris Hip, stifle, and hock
withdrawal muscle ± psoas muscles flexion
Sciatic nerve − flexor muscles of
the stifle, hock, and digits
Patellar L4–L6 Femoral Quadriceps muscle Stifle extension
Gastrocnemius a L7–S1 Tibial branch of sciatic Caudal thigh muscles: tarsal Hock extension
extensors and digital flexors
Cranial tibial a L6–S1 Fibular (peroneal) branch of sciatic Tarsal flexors, digital extensors Hock flexion
Anus Perineal S1–S3 and Caudal and Perineal and caudal rectal Caudal nerves − tail depressor Anal sphincter
caudal branches of pudendal muscles Pudendal nerve − anal contraction and tail
sphincter flexion
Skin overlying Cutaneous C8–T1 Lateral thoracic Cutaneous trunci muscles Skin twitch
thoracolumbar trunci a
vertebrae
a Sometimes may not be able to elicit in normal.

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