Where is the correct position to set right or left of muscle names for anatomical names?

Question

Muscles and bones have Latin names as can be found on wikipedia.

I need to name muscles and bones with their Latin name and I also need to specify if it's the left or the right muscle in the human body.

Where is the correct position for the Latin words for left (sinistra) and right (dextra) for a muscle or bone name?

Is there a general rule where to position this word?

Does the form of the left and right also depend on the case?

Example

The musculus latissimus dorsi exists on the humans back on the left and right side.

What is the correct naming if I explicitly want to point to the left muscle?

1. musculus latissimus dorsi sinistra
2. musculus latissimus sinistra dorsi
3. musculus sinistra latissimus dorsi
4. sinistra musculus latissimus dorsi

Edit

Since I also need the plural forms of left and right in Latin for muscles which are described as groups I think I need to use those:

Singular

• sinister sinistra sinistrum
• dexter dextra dextrum

Plural

• sinistrī sinistrae sinistra
• dextrī dextrae dextra

Source: Wikipedia sinister, Wikipedia dexter

Answer 1

Where is the correct position for the Latin words for left and right for a muscle or bone name and is there a general rule where to position this word?

In modern (English) usage, the Latin for left and right is not commonly used. Nevertheless, I think we can deduce a general rule by (1) looking at early anatomy books and (2) extrapolating from the use of other adjectives in anatomical works, both early and modern.

Thus, in Vesalius (1514-1564), we see the following examples:

ramus dexter and ramus sinister [masc. sing. nom.]

vena gastroomentalis dextra and vena gastroomentalis sinistra [fem. sing. nom.]

ostium atrioventriculare dextrum [neut. sing. nom]

From this, I think we can deduce that (a) the case, number, and gender of dexter and sinister agrees with the anatomical part under consideration (in these examples, ramus, vena, and ostium respectively); (b) the case is always in the nominative; and (c) dexter and sinister comes at the end.

If we look at other adjectives, we can see the same pattern. Again, in Vesalius:

vena mesenterica superior and vena mesenterica inferior

venae gastricae breves

aorta carotis interna

References to muscles follow the same pattern; for example:

musculus flexor pollicis brevis and musculus abductor pollicis longus

This pattern is still used in modern editions of anatomy books (I have used Moore & Dalley, 4th ed., Clinically Oriented Anatomy and Williams, Warwick, Dyson & Bannister, Gray's Anatomy, 37th ed.):

abductor pollicis longus and extensor pollicis brevis

gluteus medius

obturator internus

adductor magnus

So far, we can see a pattern like this:

• a muscle/vein/bone etc. in the nominative case

• plus the part of the body to which it belongs (typically in the genitive)

• plus an adjective describing its location/position, especially when relative to another similar structure and/or an imagined mid-line of the body (inferior and superior; internal and external; right and left), in the nominative case, agreeing with the first part

Your particular question contains a superlative (latissimus) which none of my examples include. However, I think we can make a case for it to stay with musculus as it describes the muscle, rather than locates it, in the same way abductor or flexor does in the examples above. Thus, I would write:

musculus latissimus dorsi sinister

"the widest muscle [masc. sing. nom.] of the back [gen.] left side [specifying location, masc. sing. nom. agreeing with musculus latissimus "

ADDIT: if you have more than one adjective giving location, it seems both should go at the end but dexter and sinister still always seem to be last, as in the following examples (from Vesalius):

arteria carotis interna dextra

nervus laryngeus recurrens dexter

Answer 2

It seems usage of Latin name for muscles many times does not specify the side of the body in Latin. Instead, they use English (or other languages), e.g. "left/right latissimus dorsi" (e.g. left here). However, the Latin for right and left are still used in some cases. Most of the cases I could find (without attempting to provide an exhaustive statistical analysis) seem to use the nominative case ("the right muscle X"), with a few using the genitive form ("the muscle X of the right").

For example, from this book:

(Atlas of Human Anatomy: Latin Terminology, 7th edition, by Frank H. Netter)

The above uses the nominative (as cnread noted, these are in plural).

Other examples are in this book, which lists some body parts and in parenthesis has Dextri et Sinistri (also plural) (Normal Lymph Node Topography, by Eckart Richter and Thomas Feyerabend).

Examples with singular use of nominative (dexter) can be seen here and here.

This nominative case is also suggested in the Wikipedia entry about anatomical terms of location.

Finally, regarding the order of words, in Latin this is sometimes irrelevant. Still, if you want to follow some of the medical uses referred above, a common choice seems to be

musculus latissimus dorsi sinister

(i.e the side at the end). In any case, I would not advice to use musculus latissimus sinistri dorsi, since you are breaking the muscle name apart [pun intended].