How you perform lunges can increase or decrease their risk of causing injury.
Lunges are renowned in the bodybuilding world for being an effective leg builder. By working each leg independently you reduce muscular imbalances between sides; lunge variations like the walking barbell lunge or standing alternate dumbbell lunge can be a brutal way to finish a lower-body workout, or even to pre-exhaust the quads before leg presses or squats. That being said, many bodybuilders avoid the lunge as they feel it carries a high risk of injury.
Know the Basics
Lunges are typically performed by standing with your feet shoulder-width apart. From here, you take a step forward with one leg, plant your foot firmly on the floor, then bend your knees until both are at 90 degrees. Next, push back to the start. All lunge variations hit your quads, glutes, hamstrings and calves.
Add Some Variety
Rather than just sticking to the basic lunge, many bodybuilders include more challenging variations in their training. Eight-time Mr. Olympic Ronnie Coleman was famous for his walking barbell lunges, performed outside in the parking lot of his sweltering-hot Texas gym. Even the great Arnold Schwarzenegger would perform lunges at the end of his leg workouts, so it's no surprise they're still a favorite move among bodybuilders today.
Avoid Injury with Good Form
When performed correctly, with good technique and with no pre-exisiting injuries, lunges shouldn't cause you any bother. That being said, problems can arise when you get your lunges wrong. The two main issues are your knees caving inward and your knees travelling over your toes in tandem with your heels coming off the floor, according to physical therapist Joe Heiler. If either of these issues are occurring, you're risking injury and need to either drop lunges and find another exercise, or lower the weight until you can get the technique right.
What's the Damage?
Knee injuries that occur from performing lunges incorrectly are often ligament-based, with the two main injuries affecting the anterior cruciate ligament and medial cruciate ligament, both of which support the knee joint. Patellofemoral overuse injuries are the most common knee injury in non-athletes, notes exercise scientist and personal trainer Michael Behnken. This joint is the point between your knee cap and quadriceps and repetitive movements can cause symptoms of overuse, leading to soreness and inflammation.
Try Friendlier Lunges
If you have suffered knee injuries in the past, or get pain when performing regular lunges, strength coach Ben Bruno recommends the reverse lunge as an alternative. Reverse lunges have less decelerative forces and are kinder on your knees than forward lunges. Try reverse lunges with your body weight first, then look to add barbells or dumbbells, or do them with your front foot on a step to make them more challenging and create more muscle breakdown and growth.