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Pelvic Stabilization During Resistance Training


    Arthur Jones’ MedX Lumbar Extension machine has been effective in the treatment and prevention of low back pain. The goal of this research study was to determine how exercise training affects the development of lumbar extension strength. This study was also dependent on the presence or absence of pelvic stabilization. The study included different subject groups with different measurements being observed. The success of the MedX machine and improvement in lumbar muscular strength is displayed in the study.


    Staying in good physical health is a guaranteed way to prevent pain and injury to the muscles. Low back pain, specifically in the lumbar area of the spine, is usually caused by weak muscles that can easily be strained or injured. One nonoperative treatment that can be suggested to patients suffering from low back pain is rehabilitation through strength training. Throughout the training it is essential to isolate the lumbar muscles in order for them to regain strength. In order to stabilize the lumbar extensor muscles, the pelvis must be stabilized to prevent rotation of that area. The study conducted provides data that demonstrates how isolating these muscles can help strengthen them.

    Seventy-seven (77) subjects were included in this study. All subjects had no history of low back pain or other health problems and volunteered to be a part of the study. Before the study was conducted, subjects completed two lumbar extension strength tests to determine their starting point. The strength tests measured the subjects’ maximum isometric torque of the isolated lumbar extensor muscles. The tests prior to and during the study were conducted with the MedX Lumbar Extension machine as well as other machines to compare data.. The 77 subjects were split into three training groups, each using a different machine for their tests, or a control group that did not train. Subjects trained once a week with 8 to 12 repetitions for 12 weeks where isometric torque was measured through pelvic stabilization and strength was monitored.

    The two groups that did not use the MedX Lumbar Extension machine did not demonstrate dramatic progress in terms of increased strength. In fact, these two groups ended up being combined into one research group due to the lack of significance. The subject group that had pelvic stabilization through the MedX Lumbar Extension machine did show increased isometric torque and strength in the lumbar extensor muscles. The pelvic stabilization group showed greater progress at every measurement throughout the study.