Effekter av instruktion på transversus abdominis vid stabiliseringövningar

Sammanfattning: Aim The aim of this study was to evaluate the activity recorded with electromyography (EMG) fine-wire electrodes, in transversus abdominis (TrA) and rectus abdominis (RA) while performing various stabilization exercises, and to investigate how the level of activation was affected by specific instructions Method Ten physically active women (27.1 ± 5.5year, 1.74 ± 0.05 m, 67.1 ± 8.6 kg) performed six different stabilization exercises (four lying supine with bent knees and hips and two in four point kneeling). They performed two sets of exercises, the first without and the second with specific instructions. The specific instruction was “abdominal hollowing to activate” TrA. The fine-wire electrodes were inserted bilateral into TrA and RA with an injection needle with guidance from an ultrasound. EMG was recorded during the middle second (while the subjects were asked to withhold the final position) and data was normalized to maximal voluntary contraction (MVC) and value at rest. Results The effects from instructions were significant while looking upon muscle and exercise (p<0,05). All exercises but exercise number 4 (unilateral bridgening) were significant effected by instructions in TrA, but none of the exercises were effected in RA (p>0,05). The mean of the activity in TrA varied without instructions between 2,9% (± 4,4) to 39,5 % (± 20,0) and with instructions 15,2 % (± 14,7) to 45,6 % (± 23,5). In RA the mean of the activity varied without instructions between 0,3% (± 0,8) to 9,8 % (± 27,4) and with instructions between 2.4 % (± 2,9) to 11,3% (± 28,5). Conclusion It is possible to selectively increase the activity in TrA in the majority of selected stabilization exercises with supine position with bent knees and hips, and in four point kneeling.