Muscle: Latissimus Dorsi
Action: Stretches, pulls inward, and rotates the arm toward the body's midline at the shoulder joint; moves the arm downward and backward
Innervation: Nerve supply from the thoracodorsal nerve
Muscle: Triceps Brachii
Action: Straightens the arm at the elbow joint and extends the arm at the shoulder joint
Innervation: Nerve supply from the radial nerve
Muscle: Biceps Femoris
Action: Bends the leg at the knee joint and extends the thigh at the hip joint
Innervation: Nerve supply from the tibial and fibular branches of the sciatic nerve
Muscle: Rectus Femoris
Action: Straightens the leg at the knee joint and lifts the thigh at the hip joint
Innervation: Nerve supply from the femoral nerve
Muscle: Rectus Abdominis
Action: Bends the spine and compresses the abdominal region
Innervation: Nerve supply from thoracic spinal nerves T7-T11
Muscle: External Oblique
Action: Compresses the abdominal cavity and bends the spine
Innervation: Nerve supply from thoracic spinal nerves and the iliohypogastric nerve
Muscle: Diaphragm
Action: Contracts to expand the thoracic cavity, increasing its volume
Innervation: Nerve supply from the phrenic nerve
Muscle: External Intercostals
Action: Contracts to raise the ribs and enlarge the thoracic cavity
Innervation: Nerve supply from thoracic spinal nerves T2-T12