Movement in lumbar rehabilitation program on the mat includes pilates, stretching, and gym, etc. Lumbar rehabilitation exercise program increased erector spinae muscle size and reduced a pain and disability ( Lee et al., 2012). However, exercise therapy for pain control has not widely been used clinically. For the LBP persons, exercise program reducing lumbar pain has been recommended ( Grgić, 2014). The experience back pain avoids physical activity to decrease pain, which induces muscular atrophy. Many studies have been made to identify the cause and treatment of LBP. In this study, we compared the effects of mat exercise and I-Zer exercise device on pain level and muscle activity in the patients with LBP. This device has wide been used clinically, however the exact efficacy has not been proved. I-Zer exercise device is developed for isometric exercise, and this device induces intermittent movement in the spinal vertebrae by traction, and results in correction of alignment in the balance of the left and right muscles. Traction therapy has been used for reducing pain in the LBP ( Diab and Moustafa, 2013 Wegner et al., 2013). Traction techniques for patients with LBP reduce pressure on the nerve roots. And it reduces the load of the pressure within the disc. Traction therapy relaxes ligaments and muscles around the spine. The device also has the effect on intermittent traction with isometric contraction. In the present study, Medex device was to use as a device for I-Zer isometric contraction of the lumbar spine. Medex device isotonic contraction was accompanied by an extension of the lumbar spine. Medex device showed improvement in pain relief and increment in muscle activity of the lumbar muscle ( Hong et al., 2010). The majority of isometric and resistance exercise program used the Medex device. Mat exercise is the most used type of isometric exercise, however this exercise has difficult in controlling muscle power ( Kim, 2005). Isometric exercise is safe from injury and has potent efficacy for increasing muscle strength, and it can apply to the patients with motion limitation ( Kurt and Pekünlü, 2015). Isotonic, isokinetic, and isometric exercise has been used to improve muscle strength and endurance of muscles in lumbosacral area. Increasing strength of lumbar muscle is the most important therapeutic modality for the patient with LBP. Most of patients with LBP show weakened muscle strength in lumbar spine area ( Solomonow et al., 2012).
LBP is known to be induced by tissue damage, muscle weakness, and psychological factor, etc ( Mayer et al., 2012). The 80% of the population suffer from low back pain (LBP) at least once or twice in a life time. Especially, LBP I-Zer exercise type showed more effectiveness in reducing pain degree and enhancing muscle activity. Therefore, LBP patients performed isometric exercise may have positive effect to reduce pain degree and to increase muscle activity. LBP I-Zer exercise group and LBP mat exercise group showed increased mean frequency in LT, IL, M, and RA muscles than the LBP control group. The present results showed that muscle activity in the LBP I-Zer exercise group was increased compared to the LBP mat exercise group and LBP control group ( P<0.05). The two-way ANOVA with repeated measure was used to check the pain degree and muscle activity. LBP mat exercise program and LBP I-Zer exercise program were conducted 5 sets once time, 3 times per week during 6 weeks. Root mean square (RMS), median frequency (MDF), and mean frequency (MNF) were checked by EMG power spectrum analysis on longissimus thoracic (LT), iliocostalis lumborum (IL), mulitifidus (M), and rectus abdominis (RA). Visual analogue scale (VAS) and electromyography (EMG) were used to evaluate the degree of pain and the muscle activity in LBP patients. Subjects were divided into 3 groups: LBP control group, LBP mat exercise group, and LBP I-Zer exercise group in 23–25 aged men. Isometric exercise types were mat exercise and I-Zer exercise. The purpose of the present study is to evaluate the effects of isometric exercise types on low back pain (LBP) patients.