Muscles Within The Body

Muscle	Location	Function	Sporting Example
Deltoid	Muscle on the upper arm and top of shoulder	Move the upper arm (shoulder) in all directions	Serve in tennis Front Crawl Cricket Bowling
Latissimus Dorsi	Back muscle from the lower spine to the upper arm.	Adducts and extends the arm at the shoulder	Butterfly stroke Pull ups Rowing stroke
Rotator Cuff	On the scapula in the shoulder	Rotation of the shoulder	Bowling in cricket Swimming front crawl
Pectoralis Major	Muscle covering the chest	Adducts the arm at the shoulder	Forehand shot Hand off in rugby Boxing hook
Abdominals	Side of the abdomen	Pulls the chest downwards Flexion of spinal column	Crunches
Biceps	Front of Upper Arm	Elbow flexion (bending)	Boxing uppercut Preparing to throw a javelin
Triceps	Back of Upper Arm	Elbow extension (straightening)	Throwing a javelin Hand off in rugby Boxing jab
Gluteus Maximus	Form the buttocks	Adducts & extends the hips pulling the leg backwards	Pull leg back before kicking a ball
Hip Flexors	Front of the hip	Flexes the hip, moves the hip upwards	Lifting knees when sprinting
Quadriceps	Front of Upper Leg	Knee extension (straightening)	Kicking a ball Jumping upwards on a lay-up shot
Hamstrings	Back of Upper Leg	Knee flexion (bending)	Bending knee before kicking a ball
Gastrocnemius	Calf muscle, attached by the Achilles tendon	Plantar flexion, points the toes	Running Diving Gymnastics
Tibialis Anterior	Muscle that runs down the shin	Dorsi flexion, pulls toes upwards	Ski jumping Hurdling

Functions of Muscles

• Movement: Muscles work in pairs to move bones at joints (e.g., the biceps and triceps).
• Posture: Muscles help maintain body posture by contracting and relaxing.
• Stabilization: Muscles stabilize joints to prevent dislocation during movement.
• Heat Production: Muscle activity generates heat, helping to maintain body temperature.

Muscle Types

• Skeletal Muscles: Voluntary muscles attached to bones, responsible for body movement.
• Cardiac Muscle: Involuntary muscle found only in the heart, responsible for pumping blood.
• Smooth Muscles: Involuntary muscles found in walls of internal organs, helping in movements such as digestion and blood flow.

Key Concepts

• Antagonistic Pairs: Muscles that work in opposition (e.g., biceps and triceps) to produce movement.
• Flexion and Extension: Bending and straightening movements at a joint.
• Abduction and Adduction: Moving a limb away from or toward the body's midline.
• Rotation: Movement around an axis (e.g., rotating the head or torso).