Human Body Muscles Diagram

Functions of Muscles

• Muscles enable movement by working together to perform various actions like walking, running, jumping, and picking up objects.
• They help maintain posture and support by keeping the spine upright and the body balanced.
• Muscles play a crucial role in breathing, with the diaphragm contracting and relaxing to facilitate inhaling and exhaling.
• Muscles in the digestive system facilitate the movement of food through the stomach and intestines for digestion and absorption of nutrients.
• The heart is a powerful muscle that pumps blood throughout the body, supplying oxygen and nutrients to cells.

Types of Movement

• Flexion occurs when the angle of a joint decreases, such as bending the elbow during a biceps curl.
• Extension occurs when the angle of a joint increases, such as extending the hip joint when preparing to kick a football.

Muscle Groups and Their Functions

Trapezius (Traps)

• Enable movement of the head
• Assist the upper back when lifting heavy objects

Shoulders (Delts)

• Allow for overhead lifting
• Facilitate arm rotation

Chest (Pecs)

• Control arm movement (pushing open doors, etc.)
• Play a crucial role in inhalation (breathing in)

Biceps

• Facilitate curling motion and flexing the elbow (pull-ups, lifting, etc.)
• Control the shoulder and elbow

Triceps

• Contract to straighten the arm and extend the elbow
• Counteract the action of biceps

Abs (Abdominal Muscles)

• Provide support structure and enable sitting up
• Facilitate bending the lower spine (back)
• Assist with breathing movements

Lats

• Aid in posture
• Enable pulling motions (opening a door, rowing, etc.)
• Assist when pulling heavy objects off high shelves

Forearm

• Facilitate forearm rotation (outward and inward) and flexing at the elbow
• Enable wrist movement in multiple directions

Quads

• Facilitate knee and hip movement (straightening and bending)
• Prevent knee buckling
• Used during squats, climbing stairs, standing up, and walking

Glutes

• Enable movement of legs (forwards, backwards, and sideways)
• Facilitate raising the knee to the chest, etc.

Hamstrings

• Facilitate triple extension of the ankle, knee, and hip (basis for running, jumping, and squatting)

Calves

• Enable plantar flexion of the ankle
• Facilitate toe curling and knee bending