Body movements are essential for daily activities and sports. They involve various joint types, each allowing specific motions. Understanding these movements helps us appreciate how our bodies function and move efficiently.

Joints like the ball-and-socket and hinge joints enable different ranges of motion. The shoulder offers more mobility than the hip, while the elbow and knee primarily allow flexion and extension. These differences impact how we use our limbs in everyday life.

Types of Body Movements

Types of body movements

• Flexion decreases the angle between two bones by bending a joint (elbow, knee, or hip)
• Extension increases the angle between two bones by straightening a joint (elbow, knee, or hip)
• Abduction moves a limb away from the midline of the body (raising arm laterally)
• Adduction moves a limb toward the midline of the body (lowering arm to side)
• Rotation involves turning or revolving a body part around a fixed point
  • Internal rotation rotates the limb toward the midline (rotating arm inward)
  • External rotation rotates the limb away from the midline (rotating arm outward)
• Circumduction combines flexion, extension, abduction, and adduction to create a circular motion (moving arm in a circle)
• Supination rotates the forearm so the palm faces anteriorly or superiorly (palm facing up)
• Pronation rotates the forearm so the palm faces posteriorly or inferiorly (palm facing down)

Joint structures for movement

• Hinge joints allow flexion and extension in one plane (elbow, knee, interphalangeal joints)
• Ball-and-socket joints allow flexion, extension, abduction, adduction, circumduction, and rotation (shoulder and hip joints)
• Pivot joints allow rotation around a single axis (atlantoaxial joint between C1 and C2 vertebrae, radioulnar joint between radius and ulna)
• Condyloid (ellipsoidal) joints allow flexion, extension, abduction, adduction, and circumduction (metacarpophalangeal joints or knuckles)
• Saddle joints allow flexion, extension, abduction, adduction, and circumduction (carpometacarpal joint of the thumb)
• Gliding (plane) joints allow limited sliding or twisting movements (intercarpal joints, intertarsal joints, acromioclavicular joint)
• Synovial joints are the most common type of joint in the body, allowing for a wide range of motion

Movements at different joints

• Shoulder vs. hip joint
  • Both are ball-and-socket joints allowing a wide range of motion
  • Shoulder has greater mobility due to its shallower socket
  • Hip is more stable due to its deeper socket
• Elbow vs. knee joint
  • Both are hinge joints primarily allowing flexion and extension
  • Knee allows slight rotation when flexed
  • Elbow allows supination and pronation of the forearm
• Wrist vs. ankle joint
  • Wrist is a condyloid joint allowing flexion, extension, abduction, adduction, and circumduction
  • Ankle is a hinge joint primarily allowing dorsiflexion (flexion) and plantarflexion (extension)
• Interphalangeal joints of fingers vs. toes
  • Both are hinge joints allowing flexion and extension
  • Fingers have greater range of motion and dexterity for precise movements
  • Toes have limited range of motion and primarily assist in balance and locomotion

Joint Components and Movement

• Articulations refer to the points where two or more bones meet, forming joints
• Ligaments connect bones to other bones, providing stability and limiting excessive movement
• Tendons attach muscles to bones, transferring force to produce movement
• Range of motion describes the extent of movement possible at a joint
• Biomechanics studies the mechanical laws relating to movement and structure of living organisms