Arthokinematics

Question 1

What is Arthrokinematics?

Answer 1

The movement of joint surfaces (not to be confused with Osteokinematics)

Question 2

What is Osteokinematics?

Answer 2

Bone movement

Question 3

What are the typical End-Feels?

Answer 3

Soft-tissue approximation
Bony/hard
Elastic

Question 4

What is Soft-tissue approximation end feel?

Answer 4

This is the end feel in which motion is stopped by two masses of soft tissue pressing on one another e.g elbow flexion (forearm & bicep)

Question 5

What is Bony/Hard end feel?

Answer 5

A hard (abrupt) sensation that is blocked by bone, and is painless in the normal patient e.g elbow extension

Question 6

What is the Elastic end feel?

Answer 6

When the tissues stretches which restricts the joint moving any further e.g knee flexion (quad stretches)

Question 7

What are the abnormal End-Feels?

Answer 7

Empty/Laxity
Springy
Leathery

Question 8

What is the Empty/Laxity end feel?

Answer 8

Extra movement usually due to a torn ligament

Question 9

What is the Springy end feel?

Answer 9

There is a spring, or rebound, before the normal end range of motion, and it may be painful, usually because of a loose body in the joint

Question 10

What is a Leathery end feel?

Answer 10

The joint capsule becomes too tight and make it difficult for joint to move (there may be some minor give)

Question 11

What is the Open (Loose) Pack Position?

Answer 11

-Surfaces not congruent- Any position with least amount of joint contact/congruence
-Ligaments and capsule more/ most lax
-Bony components may be moved actively or passively i.e. accessory movement is maximised
-Some distraction of the joint possible
-Often the resting position of the joint

Question 12

What is the Closed Pack Position?

Answer 12

-Maximum congruence or contact of the joint surfaces
-Ligaments and capsule maximally taut
-Joint compressed by the tension in surrounding structures i.e. accessory movement is minimised
-Usually extreme end of range of motion.
-Greatest stability e.g. full extension of the knee, elbow or IP joints.

Question 13

What are the movement of joints?

Answer 13

Spin
Roll
Slide/Glide

Question 14

What is the spin movement of the joint?

Answer 14

Where one surface spins relative to the other around a central fixed axis.

Question 15

What is the Roll movement of the joint?

Answer 15

One bone rolls on top of another. Likened to a wheel rolling along the ground.

Question 16

What is the Slide/Glide movement of the joint?

Answer 16

One bone slides across the other. Likened to a wheel skidding across an icy road.

Question 17

What is the Convex/concave rule?

Answer 17

• When a convex surface moves on a stable
  concave surface, the movement of the convex
  articulating surface occurs in the opposite
  direction.
• When a concave surface moves on a stable
  convex surface, the movement occurs in the
  same direction as the bony lever