כאב המפרקים חזק יותר אחרי תרגול ביתי.

In present-tense Hebrew, sentences like this usually do not use a verb meaning is.

So:

כאב המפרקים חזק יותר
literally looks like
the joint pain stronger

but it means
The joint pain is stronger.

This is very normal in Hebrew. The missing is is understood automatically.

This is because כאב המפרקים is a construct chain (סמיכות), which is very common in Hebrew.

It is built like this:

• כאב = pain
• המפרקים = the joints

Together, it literally means the pain of the joints.

In a construct chain, the first noun usually does not take ה־, even when the whole phrase is definite. The definiteness is determined by the last word.

So:

• כאב מפרקים = joint pain / pain of joints
• כאב המפרקים = the joint pain / the pain of the joints

That is why כאב does not have ה־ here.

Yes. That is the literal structure.

Hebrew often expresses noun combinations this way:

• כאב המפרקים = pain of the joints
• natural English translation: joint pain

So even if the English meaning shown to the learner is joint pain, the Hebrew grammar is literally a possession/association structure.

Hebrew uses מפרקים = joints because the idea is pain connected with the joints in general.

So:

• מפרק = joint
• מפרקים = joints

English often uses a singular noun before another noun, as in joint pain, but Hebrew does not build it that way here. Instead, it says something closer to pain of the joints.

Because it agrees with כאב, which is a masculine singular noun.

• כאב = pain, masculine singular
• therefore חזק = strong, masculine singular

If the subject were feminine singular, you would expect חזקה.
If it were plural, you would use a plural adjective.

So the agreement is with כאב, not with מפרקים.

Because חזק here is a predicate adjective, not an adjective directly attached inside a noun phrase.

Compare:

• כאב המפרקים חזק = the joint pain is strong
  Here חזק is part of the statement about the subject, so it does not take ה־.

But:

• כאב המפרקים החזק = the strong joint pain
  Here החזק is directly modifying the noun phrase, so it does take ה־.

This is a very important Hebrew difference.

יותר means more, and Hebrew usually forms comparatives with:

adjective + יותר

So:

• חזק = strong
• חזק יותר = stronger / more intense

This is how Hebrew normally says stronger instead of changing the adjective itself the way English often does.

Examples:

• גדול יותר = bigger
• מהיר יותר = faster
• קשה יותר = harder

So חזק יותר literally means more strong, but the natural English meaning is stronger.

The sentence does not explicitly say than X, but the comparison is understood from context.

In a sentence like:

כאב המפרקים חזק יותר אחרי תרגול ביתי

the idea is usually:

• stronger after home practice/exercise than before it, or
• stronger at that point than it normally is

Hebrew, like English, can leave the comparison unstated when it is obvious from context.

If you wanted to say it explicitly, Hebrew often uses מ־ for than:

• חזק יותר מלפני כן = stronger than before
• חזק יותר מאתמול = stronger than yesterday

Yes. In Hebrew, חזק is very commonly used for pain, symptoms, feelings, sounds, and other things that are intense.

So for pain:

• כאב חזק = strong pain
• natural English: severe pain or intense pain

So even though the literal meaning is strong, the best English sense is often severe or intense.

אחרי means after.

It introduces a time relationship:

• אחרי תרגול ביתי = after home practice / after doing exercises at home

So the sentence says that the pain becomes stronger after that activity.

It means home practice, at-home practice, or in a medical/rehab context often home exercises.

The parts are:

• תרגול = practice, exercising, drill work
• ביתי = home, domestic, home-based

So תרגול ביתי is practice or exercise done at home.

Depending on context, English could translate it as:

• home practice
• home exercise
• at-home exercise

Because Hebrew adjectives usually come after the noun they describe.

So:

• תרגול ביתי = home practice / home-based practice

This is normal Hebrew word order for noun + adjective.

Also, the adjective must agree with the noun in gender and number:

• תרגול is masculine singular
• so the adjective is ביתי, masculine singular

Because here the phrase is being used in a more general sense: after home practice/exercise, not necessarily after the specific home practice session.

So:

• אחרי תרגול ביתי = after home practice / after doing home exercises
• אחרי התרגול הביתי = after the home practice / after the specific home exercise session

Both are possible in Hebrew, but they mean slightly different things. The version in your sentence sounds more general.

Yes. The structure is very natural:

• כאב המפרקים = the joint pain
• חזק יותר = is stronger
• אחרי תרגול ביתי = after home practice

So the full sentence follows a common Hebrew pattern:

subject + predicate + time phrase

Because present-tense is is omitted, it may feel shorter than English, but the order itself is normal and clear.