1. Turning a door knob
- Muscle 1: Brachioradialis
- Action: flexes forearm at elbow joint
- Innervation: radial nerves
- Muscle 2: Supinator
- Action: supinates forearm at the radioulnar joints
- Innervation: deep radial nerve
- Muscle 3: Pronator teres
- Action: pronates the forearm at radioulnar joints
- Innervation: median nerve
2. Throwing a baseball overhead
- Muscle 1: Deltoids
- Action: flexion of arms towards overhead position, stabilizes the shoulder joint
- Innervation: axillary nerve
- Muscle 2: Latissimus dorsi
- Action: draws arm posteriorly, inferiorly, extends, adducts, and medially rotates arm at shoulder joint
- Innervation: thoracodorsal nerve
- Muscle 3: Teres major
- Action: extends arm at the shoulder joint, assists in adduction and medial rotation of arm at shoulder joint
- Innervation: lower subscapular nerve
3. Kicking a ball
- Muscle 1: Rectus femoris
- Action: flexion of thigh at the hip joint
- Innervation: lumbar spinal nerves, femoral nerve
- Muscle 2: Gluteus maximus
- Action: locks knee in extension, extends thigh at hip joint
- Innervation: inferior gluteal nerve
- Muscle 3: Adductor longus
- Action: adducts and flexes thigh at hip joint
- Innervation: obturator nerve
4. Doing sit-ups
- Muscle 1: External oblique
- Action: flexion of vertebral column bilateral/unilateral, bilateral compression of the abdomen
- Innervation: thoracic spinal nerves, iliohypogastric nerve
- Muscle 2: Rectus abdominis
- Action: flexes vertebral column, compresses abdomen (defecation, urination, forced exhalation, childbirth)
- Innervation: thoracic spinal nerves
- Muscle 3: Transversus abdominis
- Action: compression of abdomen
- Innervation: thoracic spinal nerves, iliohypogastric nerve, ilioinguinal nerve
5. Walking
- Muscle 1: Tibialis posterior
- Action: plantarflexor of the foot, support of medical longitudinal arch of foot
- Innervation: tibial nerve
- Muscle 2: Soleus
- Action: plantarflexor of ankle joint
- Innervation: tibial nerve
- Muscle 3: Gastrocnemius
- Action: plantarflexor of foot at talocrural joint
- Innervation: tibial nerve
6. Breathing
- Muscle 1: Diaphragm
- Action: contracts and flattens during inhalation
- Innervation: phrenic nerve
- Muscle 2: Internal intercostals
- Action: contracts and draws adjacent ribs together
- Innervation: thoracic spinal nerves
- Muscle 3: External intercostals
- Action: contracts and elevates ribs
- Innervation: thoracic spinal nerves