Squash Player with Muscle Imbalance

Question:

I recently started training a squash player who plays national level squash. After doing postural assessments, I’ve found she has major muscle imbalances through the upper extremity due to the over use of the same arm to repeatedly hit a shot. I have started with a flexibility program and a small portion of core work with balance training. When I move on to resistance training, will it be worth doing more reps/sets on the weaker parts of her body to try and strengthen them?

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