Throwing a baseball overhead
1. Pectoralis Major
- Action: as the pectoralis major contracts, it applies a stabilizing anterior force to the glenohumeral joint and halting rotation as the shoulder reaches maximum rotation
- Innervation: innervated by the lateral and medial pectoral nerves (root value C5-T1) which stem from the brachial plexus
2. Latissimus dorsi
- Action: becomes active as the arm reaches maximum external rotation and continues towards humeral internal rotation and applies a stabilizing anterior force to the glenohumeral joint
- Innervation: thoracodorsal nerve of the brachial plexus (C6 to C8 with C7 predominant)
Kicking a ball
1. Quadriceps Femoris
- Action: eccentrically contract to decelerate the leg wherein the energy through this contraction is held in the muscles before releasing it in a forceful contraction to the opposite direction. Extension of the knee joint.
- Innervation: Femoral nerve
2. Hamstrings
- Action: the hamstring muscle in the back of the thigh contract to bend/flex the knee and swing the leg backward.
- Innervation: nerves from the lumbar and sacral plexuses
Doing sit-ups
1. Rectus Abdominus
- Action: act eccentrically to decelerate the anterior pelvis tilting created by the extension of the hip
- Innervation: Thoracoabdominal nerves (T7-T11)
2. Transversus Abdominus
- Action: pulls tension on the pelvic bones and squeezes around the lumbar spine and pelvis. It also compresses the abdomen
- Innervation: terminal branches of the lower five intercostal nerves and the subcostal nerve from the lower six thoracic spinal nerves (T7-T12)
Breathing
1. Diaphragm
- Action: When breathing in, the diaphragm contracts and it moves down towards the abdomen creating a vacuum allowing the chest to expand and pull air. When breathing out, it relaxes and curves back up as the lungs push the air out
- Innervation: Phrenic nerve (C3-C5)
2. Intercostal muscles
- Action: as they contract, they pull the rib cage upward and outward when you inhale.
- Innervation: intercostal nerves
References:
National Center for Biotechnology Information. (2023). Nih.gov. https://www.ncbi.nlm.nih.gov/
Kenhub. (2023). Kenhub. https://www.kenhub.com/
Experts in Physiotherapy throughout the UK - Response Physio. (2023, August 9). Response Physio. https://responsephysio.com/