Kinematics of Joint Movement

Kinematic Principles of Joint Movement

Reminder: Kinematics

• Kinematics is a branch of mechanics that describes the motion of a body or its parts without regard to the forces or torques that produce the motion.

Types of Motion

• Translation: linear motion in which all parts of a rigid body move parallel to and in the same direction as every other part of the body. • Rectilinear • Curvilinear
• Rotation: circular motion around some pivot point, resulting in all points in the body rotating in the same angular path around the axis of rotation.

Osteokinematics

• Describes the motion of bones relative to the three cardinal planes of the body (curvilinear). • Sagital • Frontal • Horizontal
• Degrees of Freedom: planes of angular motion of each joint.

Open and Closed Kinetic Chains

• Open Kinetic Chain: the distal segment can rotate against the relatively fixed proximal segment.
• Closed Kinetic Chain: the proximal segment can rotate against the relatively fixed distal segment.

Arthrokinematics

• Describes the motion that occurs between the articular surfaces of joints.
• Accessory Joint Movement: occurs during osteokinematic movement, cannot be produced voluntarily in isolation. • Glide • Roll • Spin • Traction • Compression
• Combination of Arthrokinematic Movements: occurs during osteokinematic motion, e.g., roll-and-slide, roll-and-slide-and-spin.

Concave-Convex Rule

• Joint congruency: how well joint surfaces match/fit. • More congruent → more sliding • More incongruent → more rolling
• While concave surface moves on convex surface: rolling and gliding in the same direction as osteokinematic motion.
• While convex surface moves on concave surface: rolling and gliding in opposite directions.

Types of Joints

• Synarthroses: • Synostosis/Sutural • Syndesmosis • Gomphosis
• Amphiarthroses
• Diarthroses (Synovial): • Plane • Hinge joint (Ginglimus) • Pivot (Trochoid) • Elliptical (Condyloid) • Saddle (Sellar) • Ball and socket (Enarthroses)

Kinematic Analysis

• Includes an assessment of: • Position • Displacement • Velocity • Acceleration
• Methods to objectively measure human motion: • Goniometer • Electrogoniometer • Accelerometer (e.g., wearable sensors) • Imaging techniques:
  • Photography
  • Cinematography
  • Videography
  • Optoelectronics • Electromagnetic Tracking Devices

Understand the fundamental principles of kinematics, including translation and rotation, as applied to joint movement. Learn about the types of motion and their characteristics.