NU518 Week 2- Biomechanics and Kinese

Types of Joint surfaces

Planar

Ovoid

Sellar or saddle

What is the most common joint surface in the body

Ovoid

Ovoid Joint

Can identify as concave or convex

Described as a moving part on a stationary part

Can be concave on convex OR convex on concave

Sellar/Saddle

Reciprocal surfaces

Convex on concave in one plane

Concave on convex in a different plane

Types of arthrokinematic movements

Roll

Glide

Spin

Roll movement

Where different points of the first surface are in contact with different parts of the second surface (think of a ball rolling down a hill)

Glide (or slide)

Where one set point on a surface is in contact with different points of another surface (think brick sliding down a ramp)

Concave-Convex Rules

When CONVEX bone is moving on a concave surface, roll and glide move in OPPOSITE directions

When CONCAVE bone is moving on a convex surface, roll and glide move in the SAME direction

Convex moving on a concave surface

Bone end rolls in direction bone moves

Bone end glides in opposite direction

Concave moving on a convex surface

Bone end rolls in direction bone ends

Bone end glides in same direction

Types of movement

Classical and Accessory

Types of classical movement

Active ROM and Passive ROM

Types of Accessory movement

Component and Joint Play

Types of Component movement

Adjunct rotation and Conjunct rotation

Adjunct rotation

Can be controlled

Occurs because of muscle force

Conjunct rotation

Cannot be controlled

Occurs because of joint geometry

Component movement

Occur during a classical movement

Two types

Joint play movement

Occurs in response to external force

Types of joint play movement

Medial/Lateral glide or gap

Anterior/Posterior glide or gap

Distraction/compression

Planar surface

Osteokinematics - Translatory

Arthrokinematics - Glide

Ovoid surface

Osteokinematic - Swing

Arthrokinematics - roll or glide

Both can be spin

Sellar/Saddle Joint

Osteokinematic - Swing

Arthrokinematic - Roll and glide

Different roll and glide in different planes

Joint positions

Closed packed position (CPP)

Loose packed position (LPP) or rest position

Closed packed position (CPP)

Hip Joint - extension, medial rotation, abduction

Knee Joint - Full extension and lateral rotation of the tibia

Loose packed position (LPP)

Hip Joint- 30 degrees flexion, 30 degrees abduction, slight lateral rotation

Knee Joint- 25 degrees flexion

Knee Joint in CPP

Joint surfaces are not congruent

Osseous instability

Ligamentous stability: Collateral and cruciate ligaments provide stability, tighten in full extension