Skeletal joint actions
Spine Upper limbs Lower limbs
Top armLower armKneeling legExtended leg
Lateral flex-
ion, cervical
rotation and
extension
Scapular
upward rota-
tion and
elevation,
shoulder
abduction,
elbow exten-
sion
Shoulder abduc-
tion, forearm
supination
Hip extension
and adduc-
tion, knee
flexion, ankle
dorsiflexion
Hip flexion,
external
rotation,
and abduc-
tion; knee
extension;
ankle plan-
tar flexion
Muscular joint actions
Spine
Concentric contraction Eccentric contraction
To orient torso to front:
Internal oblique (flexed leg side);
external oblique (extended leg
side)
To resist falling into gravity:
External oblique, quadratus lumborum (flexed leg side)
Upper limbs
Upper arm
Concentric contraction Eccentric contraction
To upwardly rotate, abduct,
and elevate scapula:
Serratus anterior
To stabilize shoulder joint:
Rotator cuff
To extend elbow:
Triceps brachii, anconeus
To extend arm overhead without falling into gravity:
Teres major, latissimus dorsi
Lower limbs
Extended leg Kneeling leg
Concentric
contraction
Eccentric
contraction
Concentric
contraction
Eccentric
contraction
Passively
lengthening
To rotate and
abduct leg:
Sartorius, pirifor-
mis, superior
and inferior
gemellus,
obturator
internus
To keep from
collapsing
into hip:
Hamstrings
To extend,
adduct, and
internally
rotate hip:
Hamstrings,
adductor
magnus, glu-
teus maximus
To resist hip
extension and
knee flexion:
Rectus femoris
To resist knee
flexion:
Articularis genu,
vastii
Gluteus medius
and mini-
mus, tensor
fasciae latae
(continued)