Is the bean better? A comparison of abdominal and cervical muscle activity using surface EMG

PURPOSE: To compare superficial abdominal and cervical muscle activity while performing a traditional crunch with the same activity performed on a commercial device, The BeanTM. Manufacturers purport that a crunch performed on The BeanTM should produce 55-72% more activity in upper and lower rectus muscles and oblique muscles. METHOD: Thirty Four participants (males 21, females 13) performed 10 repetitions on both apparatus, in a randomly allocated order. Surface electromyography (EMG) measured the muscular activity of the upper and lower sections of the rectus abdominis (RA), the external oblique (EO) and the sternocleidomastoid (S). A repeated measures analysis of variance (ANOVA) was used to determine any significant difference in peak and half peak width for all the above muscles. RESULTS: The BeanTM did not produce significantly higher results in any of the measurements. There was significantly higher peak activity in the upper rectus performing a traditional crunch compared to a crunch performed using The BeanTM (p = 0.005), with no significant difference in the cervical EMG recordings for either peak height (mV) or half peak width (s). CONCLUSION: Our results demonstrate that this apparatus does not produce a significant increase in activity in any of the abdominal muscles, and significantly less in the upper rectus muscle group compared to a traditional abdominal crunch. The amount of work required by the long cervical flexor musculature is not significantly different between the two performances.