EMG activities between sit-and-reach and stand-and-reach: a pilot study

Some of the hamstring flexibility assessments used in Mainland China are the stand-and-reach test instead of the sit-and-reach test recommended by the American College of Sports Medicine (ACSM). The problem is that the back and leg muscles loading may be higher in stand-and-reach. This is a potential danger to the subjects when performing the stand-and-reach test. The main purpose of this study was to compare the myoelectric activities in hamstring and low back muscle during sit-and-reach test and stand-and-reach test. Four healthy physical education students participated in this study with no history of low back pain and hamstring injury. Muscle studied including semitendinosus, biceps femoris, and lumbar erector spinae. EMG activity was recorded with surface electrodes which were attached to the skin in a standardized manner. The EMG signals were received by the BTS TELEMG unit. The EMG signal was processed by ELITE data acquisition and analysis software. One-way ANOVA was employed to examine the difference in myoelectric activities between two flexibility tests. Results showed that muscle activity was relatively high during stand-and-reach test with low back muscle activity at 50%MVC in the recovery period. Furthermore, there was no significant difference in the performance of flexibility test between two different methods.