Please do not use a leg extension machine. That's the best way to do more damage to your knees. It's well known among fitness professionals that the amount of shear stress is dangerous to the knee.

The squats are good, but avoid the leg press machine too. The type of exercise you really should be working on are closed chain exercises and pay close attention to your technique. This will train your agonists and antagonists to work together in stabilizing your knee which is what you need to move efficiently. Functional closed-chain exercises like split squats, step ups and single leg deadlifts will help you develop greater stability over your knee. Using machines will only reinforce or create new imbalances and develop poor muscle activation patterns.



Also, muscle definition doesn't equate to functional performance. I've trained plenty of people who appear strong, but have no functional strength, power or endurance. Being able to do the exercises recommended above with perfect technique will benefit you more than creating hypertrophy at the quads.

Vincent Vergara
Personal Trainer/ Coach
EatSleepTrainSmart.com
EatSleepTrainSmart@gmail.com