1. Chapter 4 Arthrokinematics

2. Osteokinematic Motion―End Feel
Normal
Bony
Soft tissue stretch
Soft tissue approximation
Abnormal
Bony
Boggy
Muscle spasm
Empty
Springy block
Osteokinematics = classical or physiological motion;
End feels – quality of motion;
Bony = hard;
Soft Tissue Stretch = firm
Soft Tissue Approximation = soft
Abnormal:
boggy – acute; edema
muscle spasm – reflexive muscle guarding
springy block – cartilage involvement

3. Arthrokinematic Motion
Accessory motion terminology
Component movements
Joint play
Joint mobilization
Joint manipulation
Joint surface shape
Ovoid joint
Sellar (saddle-shaped) joint
Arthrokinematic Motion – joint surface motion
Component Movements – motions that accompany active motions but are not under voluntary control; scapula upward rotation with shoulder flex
Joint Play – spin, glide, roll
Ovoid – convex/concave
Sellar – both surfaces are conves & concave; CMC joint of thumb

4. Types of Arthrokinematic Motion
Roll
Glide or slide
Spin
Roll – new points contact new points
Glide or Slide – linear; one point on one surface contacts new points on another surface
Spin – rotation of moveable surface on fixed adjacent surface

5. Convex-Concave Rule Concave joint surface Convex joint surface
Moves in the same direction as the body segment’s motion
Convex joint surface
Moves in the opposite direction of the body segment’s movement

6. Joint Surface Positions (Joint Congruency)
When a joint is congruent, the joint surfaces
Have maximum contact with each other
Are tightly compressed
Are difficult to distract
Are in the close-packed position
See Table 4-1 page 35

7. Joint Surface Positions (Joint Congruency)
In all other positions, the joint surfaces are incongruent
Open-packed or loose-packed position
Resting position

8. Accessory Motion Forces
Traction
Approximation
Shear
Bending
Rotary
Joint Play; Requires External Force
Traction – distraction/tension; mobility
Approximation/Compression – stability
Shear – glide
Bending – compression on concave side & distraction on convex side
Rotary – twisting force