Lower Ex. Muscles

Latissimus dorsi

Attachments: Lower six thoracic vertebrae, lumbar vertebrae, iliac crest, lower ribs; Innervation: Thoracodorsal nerve; Spinal Segments: C6-C8; Action: Adduction, extension, and medial rotation of the humerus.

Levator scapulae

Attachments: Transverse processes of C1-C4; Innervation: Dorsal scapular nerve; Spinal Segments: C3-C5; Action: Elevates and downward rotates the scapula.

Trapezius

Attachments: Occipital bone, nuchal ligament, spinous processes of C7-T12; Innervation: Accessory nerve (CN XI), C3-C4; Spinal Segments: C1-C4; Action: Elevation, depression, retraction, and upward rotation of the scapula.

Serratus posterior superior

Attachments: Spinous processes of C7-T3; Innervation: Intercostal nerves T1-T4; Spinal Segments: T1-T4; Action: Proprioception of the thoracic wall.

Erector spinae

Attachments: Iliac crest, sacrum, spinous and transverse processes of lumbar and thoracic vertebrae; Innervation: Dorsal rami of spinal nerves; Spinal Segments: Lumbosacral plexus; Action: Extension and lateral flexion of the vertebral column.

Semispinalis

Attachments: Transverse processes of cervical and thoracic vertebrae; Innervation: Dorsal rami of spinal nerves; Spinal Segments: C2-T10; Action: Extension and contralateral rotation of the vertebral column.

Biceps femoris

Attachments: Ischial tuberosity and linea aspera of the femur; Innervation: Tibial division of the sciatic nerve (long head), fibular division (short head); Spinal Segments: L5-S2; Action: Flexes and laterally rotates the knee.

Flexor digitorum longus

Attachments: Posterior surface of the tibia; Innervation: Tibial nerve; Spinal Segments: L5-S2; Action: Plantar flexes the ankle and flexes digits 2-5.

Extensor digitorum longus

Attachments: Lateral condyle of the tibia and proximal fibula; Innervation: Deep fibular nerve; Spinal Segments: L5-S1; Action: Dorsiflexes the ankle and extends digits 2-5.

Gluteus maximus

Attachments: Posterior iliac crest, sacrum, coccyx; Innervation: Inferior gluteal nerve; Spinal Segments: L5-S2; Action: Extends and laterally rotates the hip.

Adductor longus

Attachments: Body of the pubis; Innervation: Obturator nerve; Spinal Segments: L2-L4; Action: Adducts, medially rotates, and flexes the hip.

Tibialis anterior

Attachments: Lateral condyle of the tibia; Innervation: Deep fibular nerve; Spinal Segments: L4-L5; Action: Dorsiflexes the ankle and inverts the foot.

Flexor hallucis longus

Attachments: Distal phalanx of the great toe; Innervation: Tibial nerve; Spinal Segments: L5-S2; Action: Plantar flexes the ankle and flexes the great toe.

Quadratus femoris

Attachments: Ischial tuberosity; Innervation: Nerve to the quadratus femoris; Spinal Segments: L5-S1; Action: Laterally rotates the hip.

Inferior gemellus

Attachments: Ischial spine; Innervation: Nerve to the quadratus femoris; Spinal Segments: L5-S1; Action: Laterally rotates the hip.

Plantaris

Attachments: Lateral supracondylar ridge of the femur; Innervation: Tibial nerve; Spinal Segments: L5-S1; Action: Flexes the knee and plantar flexes the ankle.

Obturator externus

Attachments: Outer surface of the obturator membrane; Innervation: Obturator nerve; Spinal Segments: L3-L4; Action: Laterally rotates the hip.

Soleus

Attachments: Soleal line of the tibia and fibula; Innervation: Tibial nerve; Spinal Segments: S1-S2; Action: Plantar flexes the foot at the ankle joint.

Dorsal interossei

Attachments: Adjacent sides of metatarsals 1-5; Innervation: Lateral plantar nerve; Spinal Segments: S2-S3; Action: Abducts and flexes the toes.

Flexor hallucis brevis

Attachments: Cuboid bone and lateral cuneiform; Innervation: Medial plantar nerve; Spinal Segments: S1-S2; Action: Flexes the great toe.