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