This new shape diminishes the nerve cavity eventually causing pinched nerves. Whenever we continuously perform a movement that extends or flexes the spine in a contraindicated way, our intravertebral discs slowly acquire a new deformed shape. This isn’t completely worthless of course, but it comes at a cost: The stabilizers are likely to fail under the weight of the legs by the end of the set allowing spinal compression to occur concurrently with spinal extension. Not to mention the psoas will certainly tire from all of its action because it’s so deep in the abdominal cavity, it can feel like “abs” when fatigued. This causes the build-up of lactic acid that makes the muscles feel worked. In other words, in order to prevent the spine from extending (or arching) good ol’ RA and TVA have to remain engaged isometrically for the entire set. Now, what tends to happen during a leg raise that ends at 90 degrees is the degree of force exerted upon the spine by the weight of two legs is usually greater than can be isometrically resisted by the RA, the other spinal flexor muscles (the obliques) and stabilizers (TVA). Books of Discovery 2014 But I Feel it in My Abs! That’s also not to say some people don’t need hip flexor strengthening athletes that are kickers, gymnasts, and average fitness clients that have a posterior pelvic tilt can stand to add leg raises to their routine so long as they understand the purpose of the movement. And by work, we mean to move through a range of motion for the sole purpose of developing that muscle. It does not cross the hips and has no role in hip flexion In order to work RA, which is presumably what someone is trying to do with most of their exercises on ab day, but especially the leg raise, one would need to flex the spine. The rectus abdominis (RA) attaches from the ribs to the pelvis. Past 90 degrees, all but the iliopsoas becomes actively insufficient (they go slack). The rectus femoris, TFL, and all the adductors coordinate with the iliopsoas (which is really two muscles sharing common insertion points: the iliacus and the psoas) to flex the hip but only to 90 degrees. Which muscles perform that motion? There are 11 hip flexors, most of which assist in flexion including the adductors and abductors. Raising your leg is hip flexion, and hip flexors are what flex your hip, not abdominal muscles. Unfortunately for the majority of folks favoring this type of exercise, leg raises don’t actually work your abdominal muscles effectively, if at all. You’ll often see this move in the ab-day circuit along with Russian twists and side bends (also not ideal ab moves, btw), the perpetrator of the movement swinging legs all willy-nilly up and down. If there is any move personal trainers have seen or even programmed quite frequently and largely in vain, is the hanging leg raise, or lying leg raise.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |