Throwing a baseball overhead:
Muscle 1: deltoid muscle
Action: shoulder joint movement by contracting to perform arm abduction; fundamental for raising arm overhead as the baseball is thrown
Innervation: axillary nerve
Muscle 2: Rotator cuff muscles
Action: maintain the stability of the shoulder joint during overhead movements, such as throwing, by ensuring that the head of the humerus remains properly centered within the glenoid cavity
Innervation: suprascapular nerve, axillary nerve
Kicking a ball:
Muscle 1: quadriceps femoris muscle group
Action: muscles enables the extension of the knee joint, which is essential for generating powerful leg extension during the kicking motion
Innervation: femoral nerve
Muscle 2: hamstring muscles
Action: flexing the knee joint and also play a vital role in controlling the movement of the leg during the kicking motion
Innervation: sciatic nerve
Doing sit-ups:
Muscle 1: Rectus abdominis
Action: contracts to flex the lumbar spine, bringing the torso closer to the pelvis during the sit-up movement
Innervation: lower six thoracoabdominal nerves, subcostal nerve
Muscle 2: external obliques
Action: help stabilize the trunk and provide support during the sit-up motion; work with the rectus abdominis to flex the spine forward and assist in rotational movements of the torso
Innervation: lower six thoracoabdominal nerves, subcostal nerve
Breathing:
Muscle 1: diaphragm
Action: contracts during inhalation as it flattens and increases the volume of the thoracic cavity, creating a negative pressure that draws air into the lungs
Innervation: phrenic nerves
Muscle 2: external intercostal muscles (for inhalation) and internal intercostal muscles (for forced exhalation)
Action: external intercostal muscles - elevate the ribs during inhalation, assisting in expanding the chest cavity, internal intercostal muscles - help with forced exhalation by depressing the ribs and decreasing the thoracic cavity's volume
Innervation: intercostal nerves