UL Orthotics - Prehension Patterns

Question 1

Name 6 grasp (prehension) positions

Answer 1

• cylindrical
• tip
• hook or snap
• palmar
• spherical grasp
• lateral

Question 2

Which grasp positions are considered “power grips” ?

Answer 2

• Cylindrical
• spherical
• hook (or snap)
• lateral

Question 3

What are intrinsic factors that affect pretension?

Answer 3

1. Mobility (AROM)
2. Stability
3. Contractures (PROM)
4. Balanced strength between extrinsic and intrinsic muscles
5. Sensation
6. Pain

Question 4

What extrinsic factors affect prehension?

Answer 4

1. Shape, size, weight of the object

2. Type of activity

Question 5

What factors are needed to achieve efficient prehension and effectively grasp an object?

Answer 5

We need:

• stable wrist,
• two opposing stable digits
• palmar mobility,
• sensation, and
• absence of pain

Question 6

What does the term ‘dual obliquity’ refer to?

Answer 6

The concepts relating to the anatomy of the metacarpals.

This is because of the differing lengths of the metacarpals (radial side of the hand longer than the ulnar)