Muscle imbalances and lack of range of motion about a joint are the main causes of any injury, inside or outside of the gym. Adequately strengthening all muscle groups and ensuring there is a good balance between opposing muscle groups is one of the best way to injury-proof your body while maximizing the gains you will get from your workouts. These are the ideal strength ratios between agonist/antagonist muscle groups, or in other words, muscles that opposed eachothers actions. Use these strength ratios as a guide for the muscle groups/movements you need to work on and strengthen in the gym as these are ideal ratios to maximize strength gains in full body movements such as squat, deadlift, and bench press, as well as reduce your risk of injury during exercise or sport.
Shoulder Flexors (Pecs, Deltoid, Biceps) : Shoulder Extensors (Posterior Rotator Cuff, Lats, Triceps) – 2:3
Elbow Flexors (Biceps) : Elbow Extensors (Triceps) – 1:1
Trunk Extensors (Lower Back, Quadratus Lumborum, Erector spinae) : Trunk Flexors (Rectus abdominus, Psoas) – 1:1
Hip Extensors (Glutes) : Hip Flexors (Psoas, Iliopsoas) – 1:1
Knee Extensors (Quadriceps) : Knee Flexors (Hamstrings) – 3:2
Plantarflexion/heel raise (Calves) : Dorsiflexion/toe raise (Tibialis anterior) – 3:1
Balance in Exercises (my personal thoughts on strength balance for exercises in the gym)
Bent Over Row : Bench Press – 1.5:1 (yes that means you should be able to barbell row 1.5x what you bench press)
Shoulder Press : Lat Pulldown/Chin Up – 1:1.25
Squat : Deadlift – 1:1
These are a combination of clinically proven ratios as well as my own ratios based on dealing with rehabing injuries and muscle imbalances with many patients over the years. Hope you found these ratios helpful and that is gave you some insight onto what muscle groups you may need to work on to improve your strength or get the PB you’ve been trying at. Any questions or comments feel free to write me.