Fizjoterapeuta sprawdza mięsień i więzadło.

They are the direct objects of sprawdza, so they are in the accusative case.

But in this sentence, their accusative forms happen to look the same as the nominative:

• mięsień — masculine inanimate
  
  • nominative: mięsień
  • accusative: mięsień
• więzadło — neuter
  
  • nominative: więzadło
  • accusative: więzadło

So yes, they are objects, but there is no visible change here.

In Polish, some masculine personal nouns end in -a. Fizjoterapeuta is one of them.

So even though the ending may look feminine to an English speaker, grammatically it is treated as a masculine personal noun when referring to a man.

For example:

• dobry fizjoterapeuta = a good physiotherapist
  not dobra fizjoterapeuta

Its case forms also behave like this type of masculine noun:

• nominative: fizjoterapeuta
• accusative/genitive: fizjoterapeutę / fizjoterapeuty

Sprawdza is:

• 3rd person singular
• present tense
• imperfective

from the verb sprawdzać = to check

So it can mean either:

• checks
• is checking

depending on context.

Because it is imperfective, it can describe:

• an action happening now
• a repeated/habitual action
• a general activity

Polish often uses the imperfective verb when describing an action as ongoing, repeated, or simply as a neutral present-time fact.

Here, sprawdza is natural because it means is checking / checks.

The perfective partner is sprawdzić. Its 3rd person singular form is sprawdzi, but that usually has a future meaning:

• sprawdza = is checking / checks
• sprawdzi = will check

So in a simple present-tense sentence like this one, sprawdza is the expected choice.

Polish has no articles. There is no direct equivalent of English a/an or the in ordinary sentences.

So Fizjoterapeuta sprawdza mięsień i więzadło can mean:

• A physiotherapist checks a muscle and a ligament
• The physiotherapist checks the muscle and the ligament

Context tells you which is meant.

Yes. Polish word order is more flexible than English because grammatical roles are often shown by case, not just position.

The sentence as given:

• Fizjoterapeuta sprawdza mięsień i więzadło.

is the most neutral order: subject – verb – object.

Other orders are possible, but they change the emphasis:

• Mięsień i więzadło sprawdza fizjoterapeuta.
  Emphasizes what is being checked.
• Sprawdza mięsień i więzadło fizjoterapeuta.
  Possible in context, but less neutral.

So yes, you can move things around, but the original version is the best basic one for learners.

It can mean both.

Polish present-tense imperfective verbs often cover both:

• habitual meaning: checks
• ongoing meaning: is checking

So without extra context, this sentence could mean either:

• The physiotherapist checks a muscle and a ligament
  or
• The physiotherapist is checking a muscle and a ligament

English forces you to choose more often than Polish does.

Yes. The singular here means one muscle and one ligament.

If you wanted the plural, you would say:

• mięśnie i więzadła = muscles and ligaments

So the choice depends on meaning:

• mięsień i więzadło = one muscle and one ligament
• mięśnie i więzadła = muscles and ligaments in general or several of them

Approximate English-style guides:

• mięsień ≈ MYEH-shyeń
• więzadło ≈ vye-ZA-dwo

A few useful sound notes:

• ś is a soft sh sound
• ń is like the ny sound in canyon
• ę is a nasal vowel, but in normal speech it is often pronounced less strongly than learners expect
• ł is pronounced like English w

So:

• mięsień has a soft middle sound and a soft final ń
• więzadło ends with -dło, which sounds roughly like -dwo

Yes. I is the basic Polish word for and.

In this sentence:

• mięsień i więzadło = muscle and ligament

It simply joins the two nouns together. Because both nouns are objects of sprawdza, they are both in the same case here: accusative.