Electromyographic activity of the trunk extensor muscles: Effect of varying hip position and lumbar posture during Roman chair exercise

A review of the specificity of exercises designed for conditioning the lumbar extensors

“…Roman chair or bench TEX exercise produces a significant activation of the lumbar extensors,55–61 which increases further when internal hip rotation and lumbar extension are accentuated during the movement; this being suggested to better isolate the lumbar extensors involvement 58. Indeed, even early analysis of lumbar extensor activation during exercise suggested that hyperextension from the prone position produced greatest activation 62.…”

“…During TEX based movement the hip extensors likely contribute significantly more torque during determination of MVC21–31 and thus EMG recordings for lumbar extensor MVC could be understated when determined this way, that is, may not be maximal themselves. As such this would affect the relative activation measured in the lumbar extensors during TEX exercise, potentially artificially decreasing the measured activation levels in studies that have used TEX based MVCs 45 46 56 58 59 63–67 69–72 74 75…”

The Use of Magnetic Resonance Imaging to Evaluate Lumbar Muscle Activity During Trunk Extension Exercise at Varying Intensities

“…The posture of the trunk maintained during exercise was standardized among exercise bouts and subjects as well, using a technique previously described. 35 Specifically, early rotation of the hip was limited, lumbar intersegmental extension was accentuated, and maintenance of lumbar lordosis was stressed throughout the full range of motion. Each repetition was completed in 4 seconds, 2 seconds for the concentric movement and 2 seconds for the eccentric movement.…”

Loading conditions in the spine, hip and knee during different executions of back extension exercises

“…During this test, subjects lie on a table with their held legs horizontal to the ground and attempt to hold their unsupported upper body stable for as long as possible. In a more recent development of the exercise, instead of a horizontal table, a variable-angle Roman chair is used, which allows the legs to be placed at an angle to the horizontal of, e.g., 45° [1, 5–8], and thereby allows the highest loading conditions (i.e., when the upper body is horizontal) to act at different hip flexion angles [9]. This idea has been supported by electromyography (EMG) measurements that demonstrated changes in lumbar muscle activity resulting from different starting postures and the associated changes in muscle lengths [10].…”

“…Changing the kinematic parameters during BE lead to different activation levels and different spine postures (e.g., +18% activation level for lumbar extensors with an accentuated lumbar lordosis of +25% by performing BE with an internal rotated hip) [8]. Therefore, different loading conditions act on the spine with different execution forms and lead to different risks of injury because disk deformation and ligament and spinal loading can be reduced if BE exercises are performed with neutral lordosis [11].…”