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Effect of Training Frequency and Specificity on Isometric Lumbar Extension Strength


    This research study aimed to determine how exercise and strengthening can increase lumbar extension strength in isolated areas. Two groups, a training group and a control group, were observed as the training group engaged in exercise throughout the duration of the study. The training group used the MedX Lumbar Extension machine during testing to increase their strength levels. The significant improvements in strength are displayed in the study.


    Low back pain is an increasingly common injury in industrialized societies. Most people at some point will suffer from low back pain and the burdens that come with it. While every case of low back pain is different, weak soft tissue in the lumbar area of the spine usually contributes to it or is the initial cause. Individuals who have weaker tissue in the lumbar spine are more prone to injuries of this area while people with more muscular strength are not as likely to face low back pain. This study aims to prove how isolating the lumbar muscles can train the low back while gaining strength and ultimately reducing pain.

    One hundred fourteen (114) individuals completed the testing required for the study. Before the study began, every subject completed two isometric tests observing their lumbar extension strength using the MedX Lumbar Extension machine. The 114 participants got split up into groups that each had different training frequencies. The different groups exercised between once and three times a week for 12 weeks. Each subject’s first test was a practice to ensure that each subject understood how to use the machine and correctly perform the exercise.

    Each group, no matter the training frequency, demonstrated progress in their torque output and were able to perform exercises at the full range of motion. However, the groups that trained more often progressed in more significant ways. Flexion and extension of the lumbar spine showed potential to increase through using the MedX Lumbar Extension machines. The subjects in this study all had been untrained and had relatively low strength thus the significant increase. If the subjects had more training and strength prior to participating in the study, the results would not have been as drastic.