I have a question about Lunge-Forward in the PTN Exercise Library. I agree with the instructions, but I do need more detail to back up why it is very important not to lean forward. Is there a paper or research available? The instructions state: “Keep upper torso erect. Leaning forward is potentially injurious to the spine, knee and ankle. Note: Leaning forward may be a result of poor hip joint flexibility and a weak core.”
The easiest way to answer your question is to first understand an exercise is nothing more than movement executed in a repetitive manner. To understand any movement, you must analyze the position and motion that is being performed. In addition, what forces are challenging the motion? With respect to your specific exercise mentioned, a forward lean in a lunge pattern can mean a lot of different things. For example, is a forward lean from the hips or spine, did the hips move first or spine, spine before hips? Is the forward lean driven from the bottom up or from the top down or both? How much load is being applied to the motion? What direction is the load relative to the body? These are just examples of the many questions we must ask BEFORE an exercise can be considered good or bad or a rule can be considered. In fact, there is no such thing as a good or bad exercise, just exercises (movements) that may be counterproductive to an individual’s structure, abilities and goals. There are times when we will train an individual to maintain an erect posture while lunging with the purpose of reducing hip flexion load and increasing knee flexion, therefore placing a greater load on the quadriceps during the deceleration phase of the lunge. There are also times we want to enhance a forward lean at the hips (hip flexion) to increase posterior hip (predominately glutes, adductors, hamstrings) contraction during the deceleration phase. There are also times we will want to increase hip flexion and spinal flexion while lunging to create a posterior chain deceleration action (no, this is NOT dangerous if sequenced correctly – in fact, it happens all the time). So again, ALL lunge variations can be viable IF one understands WHY. The key is not to get caught up in the NAME of the exercise or special rules; instead, understand the chain reaction that every exercise offers and select what’s best for the client. Human movement is defined as the sequencing of segments in all three planes of motion, which is the key principle to analyzing exercise safety (it’s not what you do – it’s how you do it).