Skeletal joint actions
Spine Upper limbsLower limbs
Front leg Back leg
Extension Scapular upward
rotation, abduc-
tion, and elevation;
shoulder flexion,
adduction, and
external rotation;
forearm supina-
tion; hand and
finger flexion
SI joint nutation, hip
flexion and exter-
nal rotation, knee
flexion, ankle plan-
tar flexion, foot
supination
SI joint counternuta-
tion; hip extension,
internal rotation,
and adduction;
knee flexion; ankle
plantar flexion
Muscular joint actions
Spine
Concentric contraction Eccentric contraction
To extend spine:
Spinal extensors
To neutralize twist from
position of back leg:
Internal oblique (front leg side);
external oblique (back leg
side)
To prevent hyperextension
at lumbar spine:
Psoas minor, abdominal
muscles
Upper limbs
Concentric contraction
To abduct, upwardly rotate,
and elevate scapula:
Serratus anterior, upper tra-
pezius
To stabilize, flex, and adduct
shoulder joint:
Rotator cuff, pectoralis major
(upper fibers), anterior del-
toid, biceps brachii (short
head)
To rotate forearm and grasp foot:
Supinator and flexors of hand and fingers
Lower limbs
Front leg Back leg
Eccentric contraction Concentric contraction Passively lengthening
To resist hip flexion:
Hamstrings, piriformis, obtu-
rator internus, superior and
inferior gemellus
To create hip extension
and knee flexion:
Hamstrings
To create hip extension, internal
rotation, and adduction:
Adductor magnus
Iliacus, psoas major, rectus
femoris
(continued)