Name at least three muscles that actively contracts during the following activities and name its action and innervation:
- Turning a door knob
- Supinator
- Action: Supinates forearm at radioulnar joints.
- Innervation: Median Nerve
- Brachioradialis
- Action: Flexes forearm at elbow joint; supinates and pronates forearm at radioulnar joints to neutral position.
- Innervation: Musculocutaneous and radial nerves.
- Biceps Brachii
- Action: Flexes forearm at elbow joint, supinates forearm at radioulnar joints, and fl exes arm at shoulder joint.
- Innervation: Musculocutaneous nerve.
- Throwing a baseball overhead
- Subscapularis
- Action: Medially rotates arm at shoulder joint
- Innervation: Upper and lower subscapular nerve
- Latissimus Dorsi
- Action: Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly.
- Innervation: Thoracodorsal nerve.
- Pectoralis Minor
- Action: Abducts scapula and rotates it downward
- Innervation: Medial pectoral nerve.
- Kicking a ball
- Iliacus
- Action: Hip joint: Thigh/trunk flexion
- Innervation: Femoral nerve
- Psoas Major
- Action: Psoas major flex thigh at hip joint, rotate thigh laterally, and flex trunk on hip as in sitting up from supine position.
- Innervation: Lumbar spinal nerves L2–L3.
- Psoas Minor
- Acton: Weak trunk flexion (Pirie, 2022)
- Innervation: Anterior ramus of spinal nerve L1 (Pirie, 2022)
- Doing sit-ups
- Rectus Abdominis
- Action: Flexes vertebral column, especially lumbar portion, and compresses abdomen.
- Innervation: Thoracic spinal nerves T7–T12.
- Rectus Femoris
- Action: Extends leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint.
- Innervation: Femoral Nerve
- Iliopsoas
- Action: Psoas major and iliacus muscles acting together flex thigh at hip joint, rotate thigh laterally, and flex trunk on hip as in sitting up from supine position.
- Innervation: Lumbar spinal nerves L2–L3.
- Walking
- Semitendinosus
- Action: Flexes leg at knee joint and extends thigh at hip joint.
- Innervation: Tibial nerve from sciatic nerve.
- Soleus
- Action: Talocrural joint: Foot plantar flexion (Jurkovicova, 2022).
- Innervation: Tibial nerve (S1, S2) (Jurkovicova, 2022).
- Gastrocnemius
- Action: Talocrural joint: Foot plantar flexion
Knee joint: Leg flexion
- Innervation: Tibial and fibular nerves from sciatic nerve.
- Breathing
- Diaphragm
- Action: Depresses costal cartilages, acts as primary muscle of breathing (inspiration)
- Innervation: Phrenic nerves (C3-C5) (sensory innervation of peripheries via 6th-11th intercostal nerves)
- Internal Intercostals
- Action: Depress ribs during forced expiration; support intercostal spaces and thoracic cage
- Innervation: Intercostal nerves
- External Intercostals
- Action: Elevate the ribs during forced inspiration
- Innervation: anterior rami of spinal nerves T1-T11
References:
Pirie, E. (2022, July 19). Psoas minor muscle. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/psoas-minor-muscle
Jurkovicova, E. (2022, February 14). Soleus muscle. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/soleus-muscle
Gorman, N. (2022b, August 2). Diaphragm. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/diaphragm
Vasković, J., MD. (2022a, July 6). Internal intercostal muscles. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/internal-intercostal-muscles
Vasković, J., MD. (2022a, July 6). Intercostal muscles. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/intercostal-muscles
Vasković, J., MD. (2022d, July 19). Iliacus muscle. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/iliacus-muscle