Edinburgh Handedness Inventory (EHI)

Purpose

The Edinburgh Handedness Inventory (EHI), sometimes referred to as the Edinburgh Handedness Questionnaire (EHQ), was developed by Richard Charles Oldfield to objectively determine a subject’s handedness in activities of daily living (ADL).[1] It is a common analytical tool for use of hands.[2][3]

Intended population

It has been used in a wide range of contexts from children with autism to adults with epilepsy.[2][3]

Method of Use

Its use is controversial due to the numerous variations in the instrument and a misunderstanding of the original test guidelines.[2][4] The old 20-item questionnaire contains instructions to be followed exactly when administering it. The items are compared or directly supervision or self-reporting.[1] A brief 10-item version was widely used to overcome sociocultural differences that included some related items that limited universal application.[1][3]

The original 20 items are:

1. Writing
2. Drawing
3. Throwing
4. Scissors
5. Comb
6. Toothbrush
7. Knife (without fork)
8. Spoon
9. Hammer
10. Screwdriver
11. Tennis racket
12. Knife with fork
13. Cricket bat
14. Golf club
15. Broom
16. Rake
17. Striking a match
18. Opening a box (lid)
19. Dealing cards
20. Threading a needle

From the above items 1 2 3 4 6 7 8 15 17 and 18 formed part of the 10-item EHI.

Scoring

For each of the items, the subject is requested to indicate the preferred side of the given activity (self-rating method) alternatively the subject can be made to perform the described activity and the observer is capable of presenting the findings (direct viewing method). [See the following document: https://rhd.talkbank.org/protocol/handedness.pdf] and you are done.

If the preference is left or right, then the column is + marked for that side.

If the preference for a particular category is so strong that one will not use the other category unless forced to do so, then that category is marked ++.

If neither side is desired, then + is marked on both sides.

For items involving a two-handed task such as playing a match, the hand involved in the use of the main object (i.e. the match) is considered the preferred side.

If the subject has no experience with any given task, then that item remains unmarked.

The final score is called the Laterality Quotient. It is calculated using the formula:

Laterality Quotient = (R-L)/(R+L) X 100

Here R & L refers to both the right and left marked + quantities.

The Laterality Quotient value is used to define handedness as given below:

• Left-handedness = Less than -40
• Ambidexterity = Between -40 and +40
• Right-handedness = More than +40

Psychometrics

According to Oldfield, results of self-reported EHI do not provide highly reliable results because subjects tend to overestimate the number of tasks performed by the dominant hand.[1]