Core muscle exercises were reportedly the main reason for dryland when Dr. Krabak interviewed coaches. The reason for this was injury preven...
Core muscle exercises were reportedly the main reason for dryland when Dr. Krabak interviewed coaches. The reason for this was injury prevention. Unfortunately, coaches have limited education on injury prevention or rehabilitation, making their well intentions miss the mark. We've talked about the core and dry-land mistakes before in Dryland mistake: Spinal Flexion, now we will tackle another common core exercise and debunk a few myths, the straight-leg raise or leg lift. Head to any pool deck and you'll see athletes lying on their back kicking their legs. After the hip flexors cramp up a few times, you think a coach or athlete would put together the error with this exercise for core strengthening, but to no chagrin it remains on pool decks. Why leg raise is a mistake? Does it activate the core? Simply put, it is a mistake when used excessively and does it activate the core...not really. Stuart McGill a leading researcher on core muscle activaiton performed surface electromyography (EMG) on a group of subjects and found the leg raise was the greatest activator of the psoas and rectus femoris (both hip flexors), a moderate activator of the rectus abdominus (the 6-pack muscle) and external oblique, and a poor activator of the internal oblique, internal oblique, and transverse abdominus. As you see, the exercise clearly highly activates the hip flexors, while minimally activating the non-superficial core musculature. The leg raise activates the psoas muscle, a large hip flexor running from all five lumbar vertebrae to the inside of the hip. In the majority of mechanical back pain patients I treat during swimming physical therapy, this muscle is extremely overactive and often contributing to pain and dysfunction. YOUTUBE OF CORRECT LEG LIFT This muscle activation occurs with correct form. Head to any sports team and you'll certainly see poor form. This is because many teams have horrendous coach to swimmer ratios (in the pool and in dryland), inadequate monitoring, and overzealous programs (especially in youth swimmers). This results in swimmers arching their low back, increasing joint pressure, and increasing the risk of injury while minimally strengthening the core! Poor core activation and increased risk of injury...double whammy! YOUTUBE OF POOR LEG LIFT A muscle contraction occurs when the line of the muscle either shortens (concentric) or lengthens (eccentric). Dr. Stu McGill has a simple test to see if the core contracts during a leg lift. "To prove to you that lying or hanging leg raises don’t specifically work the abdominal muscles; let me get you to lie flat on your back as if you were performing a leg raise. Place your right hand at the top of your pubic bone and your left hand on the bottom of your rib cage. Now slowly raise your legs up to the ceiling, no more than 90 degrees. Did your hands come closer together? I don’t think so!" YOUTUBE OF CORE ACTIVATION TEST When I see swimmers with low back pain, I ask them: "Do you sit a lot?" "Do you sleep on your side with your knees to your chest?" "Do you do a lot of leg lifts for dryland?" These question are often a resounding yes and some of the reasons for the higher rate of disc degeneration in swimmers. Remember, dryland training should not further increase stress on the low back, especially when it doesn't increase core strength. If doing leg lifts, make sure the form is correct. Next, dose the volume of the exercise properly, realizing it is a hip strengthening exercise! Then develop a safe, multiplanar core strengthening routine. Don't rely on only hip and spinal flexion, build a complete athlete and maximize their strength, swimming performance, and minimize their injury risk. If you want to learn more about core training for swimmers, consider purchasing Swimming Core Training. If you are interested in having Dr. John, DPT and COR develop your dryland programs, contact us today we have 2 team positions remaining. Less
