Kręgosłup boli mniej dzięki temu, że używam wałka do rolowania.

In Polish, body parts often appear without a possessive adjective when it is already obvious whose body is meant.

So:

• Kręgosłup boli mniej = The spine hurts less / My spine hurts less

Adding mój is possible, but it usually sounds more emphatic than necessary:

• Mój kręgosłup boli mniej = My spine hurts less with extra stress on my

Polish often leaves out my, your, his, etc. when context makes it clear.

Because kręgosłup is singular.

• kręgosłup = spine
• boli = hurts, is hurting

Compare:

• Kręgosłup boli = The spine hurts
• Plecy bolą = The back hurts / The back is sore because plecy is grammatically plural in Polish

So the form of boleć depends on the grammatical subject.

Mniej means less.

In this sentence:

• Kręgosłup boli mniej = The spine hurts less

It means the pain has decreased, not necessarily that it is gone completely.

Useful comparison:

• boli = it hurts
• boli mniej = it hurts less
• boli bardziej / mocniej = it hurts more
• już nie boli = it doesn’t hurt anymore

Dzięki temu, że means thanks to the fact that or more naturally because in a positive-result sense.

So:

• dzięki temu, że używam wałka do rolowania
  = thanks to the fact that I use a foam roller

The comma appears before że because że introduces a subordinate clause.

Breakdown:

• dzięki = thanks to
• temu = that, this fact
• że = that

Literally, it is something like:

• thanks to that, that I use a roller...

But natural English is:

• because I use a foam roller
• thanks to using a foam roller

Also note that dzięki usually suggests a positive cause or benefit, so it fits well here.

Because the verb używać takes the genitive case, not the accusative.

So:

• nominative: wałek
• genitive: wałka

That is why we say:

• używam wałka = I use a roller

This is an important pattern:

• używać telefonu
• używać komputera
• używać kremu
• używać wałka

A learner often expects the direct object to be accusative, but używać is one of those verbs that requires genitive.

Wałek literally means roller or small roll/cylinder, and in this context it means a foam roller used for exercise or muscle release.

• wałek = roller
• do rolowania = for rolling

So wałek do rolowania is:

• a roller for rolling
• more naturally: a foam roller

The structure noun + do + verbal noun is very common in Polish for expressing purpose:

• szczotka do włosów = hairbrush
• kubek do kawy = cup for coffee
• maszyna do pisania = typewriter
• wałek do rolowania = roller for rolling

After do, Polish normally uses a noun form, not an infinitive.

Here, rolowania is a verbal noun formed from rolować.

So:

• rolować = to roll
• rolowanie = rolling
• do rolowania = for rolling

This is very common in Polish. Compare:

• coś do jedzenia = something to eat, literally something for eating
• buty do biegania = running shoes, literally shoes for running
• maszynka do golenia = razor, literally machine for shaving

English often uses an infinitive or an -ing form, but Polish usually uses do + noun in the genitive for this kind of meaning.

Yes. Polish word order is fairly flexible, and different orders can sound more natural depending on emphasis.

Your sentence is correct:

• Kręgosłup boli mniej dzięki temu, że używam wałka do rolowania.

But these are also possible:

• Dzięki temu, że używam wałka do rolowania, kręgosłup boli mniej.
• Kręgosłup mniej boli dzięki temu, że używam wałka do rolowania.

The first version puts more emphasis on the reason/cause first.

The original version sounds natural, but many speakers might prefer the version starting with Dzięki temu, że... if they want a clearer sentence rhythm.

Both are possible, but they are not exactly the same.

• kręgosłup = spine
• plecy = back

If you mean the spinal area specifically, kręgosłup works well.

If you mean back pain more generally, many speakers might more naturally say:

• Plecy bolą mniej dzięki temu, że używam wałka do rolowania.

That sounds a bit more everyday and conversational.

So:

• kręgosłup = more specific, anatomical
• plecy = broader and often more natural in daily speech

Yes. A few natural alternatives are:

• bo = because
• ponieważ = because
• odkąd = since, ever since

Examples:

• Kręgosłup boli mniej, bo używam wałka do rolowania.
• Kręgosłup boli mniej, ponieważ używam wałka do rolowania.
• Kręgosłup boli mniej, odkąd używam wałka do rolowania.

The differences:

• bo = very common, conversational
• ponieważ = a bit more formal
• dzięki temu, że = highlights a beneficial cause
• odkąd = emphasizes that the improvement started when you began using the roller

The trickiest words are probably kręgosłup and wałka.

A rough guide:

• kręgosłup ≈ kren-go-swoop
• wałka ≈ vauw-ka or vaw-ka
• używam ≈ oo-ZHI-vam
• mniej ≈ mnyay or mnyei

A few pronunciation notes:

• ę in krę- is often pronounced more like en/em before some consonants in normal speech
• ł sounds like English w
• ż sounds like the s in measure
• mn in mniej can be hard for English speakers; try saying it as one cluster, not with a full vowel between the sounds

So kręgosłup boli mniej should flow roughly like:

• kren-go-swoop BO-lee mnyay