Disproportionate muscle growth, or having muscles on one side of the body grow more than on the other, is a normal problem in natural bodybuilding that beginners who are just getting started encounter. Listed below are my recommendations on how to deal with this problem, with sample natural bodybuilding routines on how to fix an uneven chest and shoulders.

My recommendations to fix this are:
1.Practice perfect form: By ensuring proper form not only you ensure that the targeted muscles are the ones doing the work but also that both sides are putting an equal amount of force as the movement is performed, thus preventing imbalances.
2.Concentrate on activating the muscles of the weak side: When performing the movement, really concentrate on using and squeezing the muscles of your weak side to move the weight. This extra concentration will ensure that your dominant side is not the one doing the work.
3.Perform extra sets of unilateral movements to only target the underdeveloped area: Doing a few extra sets that solely focus on your weak side will teach the body to better activate the muscle fibers of that side.
Sample Natural Bodybuilding Routines That Fix Disproportionate Muscle Growth
Listed below are a couple of examples of how you can set up a routine that will help you fix your imbalances.
Example #1: Chest Natural Bodybuilding Routine
Superset:
•Incline Bench Press 4 sets of 8-12 reps
•Unilateral Dumbbell Press 4 sets of 8-12 (Ensure that the dumbbell is light enough as you will need to balance yourself)
Superset:
•Chest Dips 3 sets of 8-12
•Unilateral Incline Flyes 3 sets of 8-12
Example #2: Shoulder Natural Bodybuilding Routine
Superset:
•Unilateral Lateral Raise 3 sets of 12-15
•Upright Rows 3 sets of 8-12
Superset:
•Bent Over Laterals 3 sets of 10-12
•Unilateral Shoulder Dumbbell Press 3 sets of 12-15
Routine Notes: Only rest 1 minute in between supersets and watch those lagging areas grow.
What If One Whole Side of the Body Is Visibly More Developed Than the Other One?
If one side of the body is visibly more developed than the other, as often happens to athletes who practice sports like bowling, where one side is used predominantly, then I would recommend dedicating whole workouts to exercising only the weak side.
The sample natural bodybuilding workouts below illustrate how to set up a unilateral bodybuilding routine that for example purposes is targeting the left side of the body (as the right side is the more developed one):
Workout (A) Chest/Back/Biceps/Triceps (Monday)
Workout (B) Delts/Thighs/Hamstrings/Calves (Tuesday)
Off (Wednesday)
Workout (C) Chest/Back/Biceps/Triceps (Thursday)
Workout (D) Delts/Thighs/Hamstrings/Calves (Friday)
Off (Weekend)
Workouts (A) and (B) train both sides of the body equally while Workouts (C) and (D) should just consist of unilateral movements for the left side only. See the sample unilateral workouts below:
Workout (C)
•Unilateral Incline Dumbbell Press 4 sets of 8-12 reps
•Unilateral Flat Dumbbell Press 4 sets of 8-12 reps
•Unilateral Pulldown (use a pulley) 4 sets of 8-12 reps
•Unilateral Dumbbell Row 4 sets of 8-12 reps
•Concentration Curl 3 sets of 8-12 reps
•Hammer Curl 3 sets of 8-12 reps
•Triceps Pushdown (Use Pulley; Palm of hand facing down) 3 sets of 8-12 reps
•Overhead Dumbbell Triceps Extension (left arm only) 3 sets of 8-12 reps
Workout (D)
•Unilateral Shoulder Press 3 sets of 8-12 reps
•Unilateral Rear Delt Machine 3 sets of 8-12 reps
•Unilateral Lateral Raise 2 sets of 8-12 reps
•Lunges (left side only) 4 sets of 8-12 reps
•Unilateral Leg Press (left side only) 3 sets of 8-12 reps
•Unilateral Leg Extensions 2 sets of 8-12 reps
•Unilateral Leg Curls 4 sets of 8-12 reps
•Unilateral Calf Press 3 sets of 8-12 reps
Workout Notes: Only rest 1 minute in between sets.
I hope that this gets your questions on uneven muscle growth answered!
Take care and train hard!
Until next time, take care and train hard!